<b>Bijsluiter</b>. De hyperlink naar het originele document werkt niet meer. Daarom laat Woogle de tekst zien die in dat document stond. Deze tekst kan vreemde foutieve woorden of zinnen bevatten en de opmaak kan verdwenen of veranderd zijn. Dit komt door het zwartlakken van vertrouwelijke informatie of doordat de tekst niet digitaal beschikbaar was en dus ingescand en vervolgens via OCR weer ingelezen is. Voor het originele document, neem contact op met de Woo-contactpersoon van het bestuursorgaan.<br><br>====================================================================== Pagina 1 ======================================================================

<pre>β-Chloroprene
Evaluation of the effects on reproduction, recommendation for classification
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<pre>Gezondheidsraad                              Voorzitter
Health Council of the Netherlands
Aan de Staatssecretaris Sociale Zaken en Werkgelegenheid
Onderwerp           : Aanbieding advies ‘β-Chloroprene’
Uw kenmerk          : DGV/MBO/U-932542
Ons kenmerk         : U 96/AvdB/ra/543-K6
Bijlagen            :1
Datum               : 18 februari 2003
Mijnheer de staatssecretaris,
Bij brief van 3 december 1993, nr DGV/MBO/U-932542, verzocht de Staatssecretaris van
Welzijn, Volksgezondheid en Cultuur namens de Minister van Sociale Zaken en Werkgelegenheid
om naast het afleiden van gezondheidskundige advieswaarden ook te adviseren over andere
onderwerpen ten behoeve van de bescherming van beroepsmatig aan stoffen blootgestelde
personen. In 1995 heeft de Staatssecretaris van Sociale Zaken en Werkgelegenheid besloten tot het
opstellen van een zogenaamde niet-limitatieve lijst van voor de voortplanting vergiftige stoffen.
Op deze lijst komen stoffen die volgens de richtlijnen van de Europese Unie ingedeeld moeten
worden in categorie 1, 2 en 3 wat betreft effecten op de voortplanting en stoffen die schadelijk
kunnen zijn voor het nageslacht via de borstvoeding. De Gezondheidsraad is verzocht om voor
stoffen een classificatie volgens de EU-criteria voor te stellen.
      In dit kader bied ik u hierbij een advies aan over β-chloropreen. Dit advies is opgesteld door
de Commissie Reproductietoxische stoffen van de Gezondheidsraad en beoordeeld door de
Beraadsgroep Gezondheid en Omgeving.
Ik heb deze publicatie heden ter kennisname aan de Minister van Volksgezondheid, Welzijn en
Sport en aan de Minister van de Volkshuisvesting, Ruimtelijke Ordening en Milieu gestuurd.
Hoogachtend,
prof. dr JA Knottnerus
Bezoekadres                                                              Postadres
Parnassusplein 5                                                         Postbus 16052
2511 VX     Den Haag                                                     2500 BB    Den Haag
Telefoon (070) 340 7520                                                  Telefax (070) 340 75 23
E-mail: A.vd.burght@gr.nl                                                www.gr.nl
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<pre>β-Chloroprene
Evaluation of the effects on reproduction, recommendation for classification
Committee for compounds toxic to reproduction
A Committee of the Health Council of the Netherlands
to:
the Minister and State Secretary of Social Affairs and Employment
No. 2003/06OSH, The Hague, February 18, 2003
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<pre>The Health Council of the Netherlands, established in 1902, is an independent scientific
advisory body. Its remit is “to advise the government and Parliament on the current level
of knowledge with respect to public health issues...” (Section 21, Health Act).
     The Health Council receives most requests for advice from the Ministers of Health,
Welfare & Sport, Housing, Spatial Planning & the Environment, Social Affairs &
Employment, and Agriculture, Nature Preservation & Fisheries. The Council can
publish advisory reports on its own initiative. It usually does this in order to ask
attention for developments or trends that are thought to be relevant to government
policy.
     Most Health Council reports are prepared by multidisciplinary committees of Dutch
or, sometimes, foreign experts, appointed in a personal capacity. The reports are
available to the public.
Preferred citation:
Health Council of the Netherlands: Committee for Compounds toxic to reproduction. β-
Cloroprene; Evaluation of the effects on reproduction, recommendation for
classification. The Hague: Health Council of the Netherlands, 2003; publication no.
2003/06OSH.
all rights reserved
ISBN: 90-5549-465-8
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<pre>    Contents
    Samenvatting 7
    Executive summary 8
1   Scope 9
1.1 Background 9
1.2 Committee and procedure 9
1.3 Additional considerations 10
1.4 Labelling for lactation 11
1.5 Data 11
1.6 Presentation of conclusions 12
1.7 Final remark 12
2   β-Chloroprene 13
2.1 Introduction 13
2.2 Human studies 14
2.3 Animal studies 15
2.4 Overall conclusions 19
    Contents                       5
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<pre>  References 21
  Annexes 24
A The committee 25
B Comments on the public draft 27
C Directive (93/21/EEC) of the European Community 28
D Fertility and developmental toxicity studies 34
E Abbreviations 39
  Contents                                           6
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<pre>Samenvatting
Op verzoek van de Minister van Sociale Zaken en Werkgelegenheid beoordeelt de
Gezondheidsraad de effecten op de reproductie van stoffen waaraan mensen tijdens de
beroepsuitoefening kunnen worden blootgesteld. De Commissie Reproductietoxische
stoffen, een commissie van de Raad, adviseert een classificatie van reproductietoxische
stoffen volgens Richtlijn 93/21/EEC van de Europese Unie. In het voorliggende rapport
heeft de commissie β-chloropreen onder de loep genomen.
De aanbevelingen van de commissie zijn:
• Voor effecten op de fertiliteit is de commissie van mening dat er onvoldoende
    geschikte humane gegevens beschikbaar zijn en dat voldoende diergegevens laten
    zien dat β-chloropreen de fertiliteit niet schaadt. Daarom adviseert de commissie β-
    chloropreen niet te classificeren.
• Voor ontwikkelingsstoornissen is de commissie van mening dat er onvoldoende
    geschikte humane gegevens beschikbaar zijn en dat voldoende diergegevens laten
    zien dat β-chloropreen de ontwikkeling van het nageslacht niet schaadt. Daarom
    adviseert de commissie β-chloropreen niet te classificeren.
• Voor effecten tijdens lactatie adviseert de commissie om β-chloropreen niet te
    kenmerken wegens onvoldoende gegevens.
Samenvatting                                                                             7
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<pre>Executive summary
On request of the Minister of Social Affairs and Employment, the Health Council of the
Netherlands evaluates the effects on the reproduction of substances at the workplace.
The Health Council's Committee for Compounds Toxic to Reproduction recommends to
classify compounds toxic to reproduction according to the Directive 93/21/EEC of the
European Union. In the present report the committee has reviewed β-chloroprene.
The committee's recommendations are:
• For effects on fertility, the committee is of the opinion that a lack of appropriate
    human data precludes the assement of ß-chloroprene for fertility and sufficient
    animal data show that no classification for effects on fertility is indicated.
• For developmental toxicity, the committee is of the opinion that a lack of
    appropriate human data precludes the assement of ß-chloroprene for effects on
    development and sufficient animal data show that no classification of β-chloroprene
    is indicated.
• For effects during lactation, the committee is of the opinion that due to the lack of
    appropriate data β-chloroprene should not be labelled.
Executive summary                                                                       8
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<pre>Chapter 1
        Scope
1.1     Background
        As a result of the Dutch regulation on registration of compounds toxic to reproduction
        that came into force on 1 April 1995, the Minister of Social Affairs and Employment
        requested the Health Council of the Netherlands to classify compounds toxic to
        reproduction. The classification is performed by the Health Council's Committee for
        Compounds Toxic to Reproduction according to the guidelines of the European Union
        (Directive 93/21/EEC). The committee's advice on the classification will be applied by
        the Ministry of Social Affairs and Employment to extend the existing list of compounds
        classified as toxic to reproduction (class 1, 2 or 3) or labelled as may cause harm to
        breastfed babies (R64).
1.2     Committee and procedure
        The present document contains the classification of β-chloroprene by the Health
        Council's Committee for Compounds Toxic to Reproduction. The members of the
        committee are listed in Annex A. The first draft of this report was prepared by dr
        J Krüse and dr JAGM van Raaij of the OpdenKamp Registration & Notification, The
        Hague, The Netherlands, by contract with the Ministry of Social Affairs and
        Employment. The proposed classification is based on the evaluation of published human
        and animal studies concerning adverse effects with respect to fertility and development
        and lactation of the above mentioned compound.
        Scope                                                                                   9
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<pre>    Classification and labelling was performed according to the guidelines of the European
    Union listed in Annex C.
    Classification for fertility and development:
    Category 1        Substances known to impair fertility in humans (R60)
                      Substances known to cause developmental toxicity in humans (R61)
    Category 2        Substances which should be regarded as if they impair fertility in humans (R60)
                      Substances which should be regarded as if they cause developmental toxicity in humans
                      (R61)
    Category 3       Substances which cause concern for human fertility (R62)
                      Substances which cause concern for humans owing to possible developmental toxic
                      effects (R63)
    No classification for effects on fertility or development
    Labelling for lactation:
                      May cause harm to breastfed babies (R64)
                      No labelling for lactation
    In 2002, the President of the Health Council released a draft of the report for public
    review. The individuals and organisations that commented on the draft report are listed
    in Annex B. The committee has taken these comments into account in deciding on the
    final version of the report.
1.3 Additional considerations
    The classification of compounds toxic to reproduction on the basis of the Directive
    93/21/EEC is ultimately dependent on an integrated assessment of the nature of all
    parental and developmental effects observed, their specificity and adversity, and the
    dosages at which the various effects occur. The directive necessarily leaves room for
    interpretation, dependent on the specific data set under consideration. In the process of
    using the directive, the committee has agreed upon a number of additional
    considerations.
    • If there is sufficient evidence to establish a causal relationship between human
        exposure to the substance and impaired fertility or subsequent developmental toxic
        effects in the progeny, the compound will be classified in category 1, irrespective
        the general toxic effects (see Annex C, 4.2.3.1 category 1).
    • Adverse effects in a reproductive or developmental study, in the absence of data on
        parental toxicity, occurring at dose levels which cause severe toxicity in other
        studies, need not necessarily lead to a category 2 classification.
    Scope                                                                                                   10
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<pre>    •    If, after prenatal exposure, small reversible changes in foetal growth and in skeletal
         development (e.g. wavy ribs, short rib XIII, incomplete ossification) in offspring
         occur in a higher incidence than in the control group in the absence of maternal
         effects, the substance will be classified in category 3 for developmental toxicity. If
         these effects occur in the presence of maternal toxicity, they will be considered as a
         consequence of this and therefore the substance will not be classified for
         developmental toxicity (see Annex C, 4.2.3.3 developmental toxicity final
         paragraph).
    •    Clear adverse reproductive effects will not be disregarded on the basis of
         reversibility per se.
    •    Effects on sex organs in a general toxicity study (e.g. in a subchronic or chronic
         toxicity study) may warrant classification for fertility.
    •    The committee not only uses guideline studies (studies performed according to
         OECD standard protocols* for the classification of compounds, but non-guideline
         studies are taken into consideration as well.
1.4 Labelling for lactation
    The recommendation for labelling substances for effects during lactation is also based
    on Directive 93/21/EEC. The Directive defines that substances which are absorbed by
    women and may interfere with lactation or which may be present (including
    metabolites) in breast milk in amounts sufficient to cause concern for the health of a
    breastfed child, should be labelled with R64. Unlike the classification of substances for
    fertility and developmental effects, which is based on a hazard identification only
    (largely independent of dosage), the labelling for effects during lactation is based on a
    risk characterisation and therefore also includes consideration of the level of exposure of
    the breastfed child.
         Consequently, a substance should be labelled for effects during lactation when it is
    likely that the substance would be present in breast milk in potentially toxic levels. The
    committee considers a concentration of a compound as potentially toxic to the breastfed
    child when this concentration leads to exceedence of the exposure limit for the general
    population, eg the acceptable daily intake (ADI).
1.5 Data
    Literature searches were conducted in the online databases Toxline and Medline,
    starting from 1966 up 2000. Literature was selected primarily on the basis of the text of
*    Organisation for Economic Cooperation and Development
    Scope                                                                                       11
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<pre>    the abstracts. Publications cited in the selected articles, but not selected during the
    primary search, were reviewed if considered appropriate. In addition, handbooks and a
    collection of most recent reviews were consulted.
         Human studies on β-chloroprene regarding its effects on fertility and development
    are described in the text and summarised in Annex D. Of each study the quality of the
    study design (performed according to internationally acknowledged guidelines) and the
    quality of documentation are considered.
         Animal data are described in the text and summarised in Annex D.
1.6 Presentation of conclusions
    The classification is given with key effects, species and references specified. In case a
    substance is not classified as toxic to reproduction, one of two reasons is given:
    • Lack of appropriate data preclude assessment of the compound for reproductive
         toxicity.
    • Sufficient data show that no classification for toxic to reproduction is indicated.
1.7 Final remark
    The classification of compounds is based on hazard evaluation* only, which is one of a
    series of elements guiding the risk evaluation process. The committee emphasises that
    for derivation of health based occupational exposure limits these classifications should
    be placed in a wider context. For a comprehensive risk evaluation, hazard evaluation
    should be combined with dose-response assessment, human risk characterisation,
    human exposure assessment and recommendations of other organisations.
*   for definitions see Tox95
    Scope                                                                                     12
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<pre>Chapter 2
        β-Chloroprene
2.1     Introduction
        Name                  :    β-chloroprene
        synonyms              :    2-chloro-1,3-butadiene, 2-chlorobuta-1,3-diene,
                                   2-chlorobutadiene, chlorobutadiene, chloroprene,
                                   β-chloroprene
        CAS-no                :    126-99-8
        EINECS no             :    240-818-0
        Examples of use       :    as chemical intermediate in the production of polychloroprene
                                   (neoprene) elastomer
        Mol weight            :    88.5
        Molecular formula     :    C H Cl
                                     4 5
        Chem formula          :    CH =CCl-CH=CH
                                       2             2
                                                                              o
        Conversion factor     :    1 ppm = 3.68 mg/m3 at 760 mm Hg and 20 C
                                   1 mg/m3 = 0,272 ppm
        β-Chloroprene readily polymerizes when exposed to light and heat and can oxidize to
        form peroxides, acids and other products. In some studies, β-chloroprene vapour
        generation was achieved by bubbling air through chloroprene, but the methods used to
        prepare and generate the concentrations of β-chloroprene for inhalation studies are often
        not specified. Therefore many signs of toxicity reported in the literature may be due to
        the fact that the test animals were exposed to reaction products of β-chloroprene such as
        β-Chloroprene                                                                             13
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<pre>    dimers and peroxides. This may explain the observed inconsistencies between the
    results of different research groups (Cul78). Moreover, due to its reactivity
    β-chloroprene should be stored at 0ºC or below under nitrogen and may contain
    significant quantities of inhibitors.
2.2 Human studies
    Koëter et al reviewed several Russian studies (Koë89). In these studies, menstrual
    disorders, increased number of miscarriages and functional disturbances in
    spermatogenesis were described. Barlow et al (Bar82) cited a study concerning male
    workers in a polychloroprene factory in France. One hundred of 130 workers exposed to
    chloroprene showed symptoms of gross over-exposure (chemical burns). In addition, in
    some of these workers conjunctivitis, hair loss and sexual impotence, involving both
    libido and sexual dynamics, were observed. (Bar82). Sanotskii (San76) cited a Russian
    study with 143 workers in β-chloroprene shops. Functional disturbances in
    spermatogenesis and morphological abnormalities of sperm were described. In addition,
    an increased number of spontaneous abortions in the wives of β-chloroprene exposed
    workers was found
         The committee concluded that data on the human toxicity of β-chloroprene are
    scarce and that the quality of the available studies is limited. Moreover, it is possible that
    effects observed may be related to exposure to other compounds than β-chloroprene,
    since it is often used in a (rubber) industrial environment with exposure to several
    chemicals. This might explain the large differences between the no effect levels in
    studies from East and West-Europe. However, in none of the human studies the
    exposure was measured or specified.
    Fertility
    No publications were found concerning effects of pure β-chloroprene on human fertility.
    Developmental studies
    No publications were found concerning effects of pure β-chloroprene on human
    development.
    Lactation
    No publications were found concerning the effects on lactation and the excretion of pure
    β-chloroprene in human breast milk.
    β-Chloroprene                                                                                  14
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<pre>2.3 Animal studies
    Tables 1 and 2 (Annex D) summarise the fertility and developmental toxicity studies
    with β-chloroprene in experimental animals.
    Fertility
    In two dominant lethal tests, male C57BL/6 mice were exposed to 0, 0.064, 0.32 or 3.5
    mg/m3 β-chloroprene (14-15/group) or to 0, 0.05, 0.13 and 1.85 mg/m3 β-chloroprene
    (8-11/group) by inhalation for two months. After exposure the males were mated to 2 or
    3 untreated females. In both experiments, fertility (expressed as fertilizing ability) was
    unaffected. In the first experiment, the total embryonic mortality increased from 29% in
    the controls to 52, 50 and 63% at 0.064, 0.32 and 3.5 mg/m3, respectively. In the second
    experiment, embryonic mortality increased from 19% in the controls to 33, 36 and 42%
    at 0.05, 0.13 and 1.85 mg/m3 respectively (San76).
         In a dominant lethal study of Sanotskii (San76), male white rats (10/group; strain
    not specified) were exposed to 0, 0.057 and 0.14 mg/m3 β-chloroprene for 2.5 months
    (further specification of exposure not given) and thereupon mated to untreated females.
    The embryonic death rate was increased from 10% in the controls and the 0.057 mg/m3
    group to 21% in the highest dose group. The majority of the deaths occurred after
    implantation.
         In two studies of Immel and Willems (Imm78a, Imm78b), male Wistar rats (12/
    group) were exposed to 0 and 180 mg/m3 or to 0 and 360 mg/m3 β-chloroprene by
    inhalation for 6 hours/day during 5 days. Thereafter, they were mated with 2 untreated
    females/week during 8 weeks. Females were sacrificed 15 days after the mid-week of
    their mating with the males, and checked for pregnancy. No mortality or abnormalities
    of condition or behaviour were observed in the males during the exposure period and the
    eight weeks thereafter. However, during the exposure period the control group did not
    gain weight and the exposed rats lost weight. The number of corpora lutea, and live and
    dead implants were determined. In the survivors, no effects on fertility or on mortality of
    embryos and foetuses were observed.
         In a similar study by Immel and Willems (Imm78c), Swiss male mice (12/group)
    were exposed to 0, 36 and 360 mg/m3 β-chloroprene for 6 hours/day and 5 days/week
    during two weeks. Subsequently, they were paired to untreated females during 8 weeks.
    At the highest dose, 8 of the 12 males died during the first three days of exposure. In the
    survivors, no effects on fertility or on mortality of embryos and foetuses were observed.
         Immel and Willems (Imm79) exposed male rats (5/group) to 0, 36, 120 and 360
    mg/m3 (0, 10, 33 and 100 ppm) β-chloroprene by inhalation for 6 hours/day, 5 days/
    β-Chloroprene                                                                               15
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<pre>week during 3 or 6 months. No dose related changes in sperm concentration or
morphological abnormalities were found. However, evaluation of the study is difficult,
because of the small size of the treatment groups and the wide variations in different
types of abnormalities observed within and between the treatment groups (Imm79).
     Mice (C75BL/6, 7-8/dose), that were exposed to 0.06, 0.32, and 3.5 mg/m3 β-
chloroprene during two months, showed adverse effects on the spermatogenesis by an
increase in the number of tubules with desquamating germinal epithelium at the two
highest doses. The effect was dose-related. However, neither the spermatogenesis index,
nor the total number of spermatogonia were affected at these dose levels (San76).
     Appelman and Dreef-van der Meulen studied the effects of β-chloroprene on male
and female reproduction in a two-generation study in rats (App79). Male Wistar rats
(F0, 25/group) were exposed to 0, 36, 120, and 360 mg/m3 β-chloroprene by inhalation
for 6 hours/day, 5 days/week during 13 weeks. Thereupon, they were mated with
untreated females. No effects on the fertility of the males of the F0-generation were
observed, nor on the intra-uterine mortality and the litter size. Microscopic examination
of the testicles did not show any abnormality. However, a reduction in body weight gain
was observed in the highest dose group. Male and female animals from the F1-
generation (20/sex/group) were exposed to the same levels as the F0-generation during
10 weeks from week 4 after birth. No adverse effects with respect to intrauterine death
and litter size were observed. Again reduction in body weight gain (growth retardation)
was observed in the medium and high dose groups. The relative weights of liver and
ovaries in the female rats were elevated after exposure to 360 mg/m3. No effects on
postnatal mortality and general condition of the F1-generation were observed.
     In a similar two-generation study, female rats (F0, 25/group) were exposed to 0, 36,
120, and 360 mg/m3 β-chloroprene (6 hours/day, 5 days/week) during 13 weeks.
Thereupon they were mated with untreated males. The offspring was again exposed
during 10 weeks. No adverse effects with respect to intrauterine death, litter size,
postnatal death and general condition of the offspring were observed. In the F0-
generation, a decrease in body weight gain was observed in the highest dose group and
in the F1-generation both at 119 and 360 mg/m3. In the F1-generation, the reduction in
growth was more pronounced than in the F0-generation, but this was attributed to a
difference in diet between the two generations. The β-chloroprene used in these studies
was freshly purified (App79).
     In another study, male rats (Charles River-CD, 5/group) were exposed to 0 and 90
mg/m3 of β-chloroprene, 4 hours daily for 22 consecutive days. Thereupon they were
mated with untreated virgin females (3 new females/male each week) for 8 consecutive
weeks. Mated females were allowed to deliver and raise their pups to weaning. The
results showed that the reproductive capability of the male rats was not affected, as no
adverse effects were observed on fertility, litter size and postnatal survival of the
β-Chloroprene                                                                             16
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<pre>offspring. The mating index, number of pups/litter, the viability index and the lactation
index were not affected. The β-chloroprene used in the study had a purity of 99.9% and
contained less than 50 ppm dimers (Cul78).
     F344/N rats (10/group/sex) were exposed to β-chloroprene by inhalation at
concentrations of 0, 5, 12, 32, 80 and 200 ppm for slightly more than 6 hours/day, 5
days/week for 13 weeks. Sperm motility and vaginal cytology evaluations were
performed on all rats exposed at 0, 5, 32, and 200 ppm (0, 18, 115 and 720 mg/m3)
β-chloroprene. Reproductive parameters evaluated included testicular weight,
epididymal weight, caudal weight, sperm count, sperm motility, and sperm morphology
in males and oestrual cyclicity in females. Complete necropsy was performed on all
animals, 24 hours after the last exposure. One male rat in the 200 ppm (720 mg/m3)
group died on the second day of exposure, but no other early mortalities occurred. No
effects on body weights of males and females were observed. Clinical findings in the
200 ppm (720 mg/m3) males included red or clear discharge around the nose and eyes.
An exposure-related increase in mean absolute kidney weight was observed in males at
200 ppm (720 mg/m3) and in females at the two highest dose levels, but this increase
was not associated with histopathological changes in the kidney. In the rats, exposure to
80 ppm chloroprene or higher caused degeneration and metaplasia of the olfactory
epithelium. Exposure to 200 ppm (720 mg/m3) β-chloroprene caused anemia,
hepatocellular necrosis and a significant reduction in sperm motility, 80.0% vs. 86.7% in
the controls. No atrophy of the testes was observed. β-Chloroprene did not affect other
male reproductive parameters or interfere with oestrual cyclicity in females (Mel96).
     B6C3F1 mice (10/group/sex) were also exposed in this study in the same way as the
rats. In contrast to the rat study, the 200 ppm (720 mg/m3) exposure level was not tested
since all mice died in a two week pilot exposure at this level. Sperm motility and vaginal
cytology evaluations were performed at 0, 12, 32 and 80 ppm (43, 115, 288 mg/m3)
β-chloroprene. During the exposure period no deaths were observed. Body weight gain
in the highest exposure group was slightly lower than that of the controls. No exposure
related effects were observed in organ weights (including testes), haematology or
clinical chemistry parameters. No atrophy of the testes was observed. The exposure did
not affect the male reproductive parameters or alter the oestrual cyclicity in females. The
purity of the ß-chloroprene used in this study was greater than 97.9 % and contained less
than 0.2 % chloroprene dimers. The peroxide content was less than 0.2 mequivalent/kg
chloroprene (Mel96).
Development
In two studies by Culik et al (Cul 78), pregnant rats were exposed to 0, 3.6, 36 and
90 mg/m3 β-chloroprene by inhalation for 4 hours daily, using two different exposure
β-Chloroprene                                                                               17
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<pre>protocols. In the first study, dams (43-48/group) were exposed on days 1-12 and
sacrificed on day 17 to evaluate the embryotoxic potential of β-chloroprene. In a second
teratology study, dams (19-24/group) were exposed on days 3-20 of gestation and
sacrificed on day 21. In both studies, no maternal, embryonal or foetal toxicity was
observed. Litter size, average numbers of implantation sites per litter, and
pre-implantation losses among exposed females did not differ significantly from the
controls. Only in the teratology study at an exposure level of 36 mg/m3, a slight but
statistically significant increase in the number of dams with resorptions was observed.
However, this was judged not to be of toxicological significance, as it was not observed
at 90 mg/m3 or in the embryotoxicity study. In the teratology study, there was a slight
but statistically significant increase in the average body weight of the foetuses of dams
exposed to 90 mg/m3. Foetuses from dams exposed to 36 and 90 mg/m3 showed a
significantly increased crown-rump length. Also a significant increase in foetal body
weight was observed at he highest dose. No major external, skeletal or soft tissue
malformations were seen. The committee concluded that neither developmental toxicity
nor maternal toxicity was observed in this study. Therefore, these results were
considered inconclusive (Cul78).
     Koëter and Appelman (Koë80) exposed pregnant Wistar rats to 0, 36, 90, 270 and
360 mg/m3 β-chloroprene by inhalation for 6 hours/day. In a preliminary study (7
animals/group), the rats were exposed on gestation days 6-16, whereas in an extended
study with 30 animals/group, exposure occurred at days 4-16 of gestation. The animals
were sacrificed on day 21 of gestation and evaluated for maternal toxicity,
embryotoxicity and teratogenicity. In the extended study, the foetuses were examined for
visceral and skeletal effects. At the three highest doses reduction in growth and food
intake was observed. Apart from some foetal growth depression, which was not
considered to be biologically significant, no signs of embryotoxicity or teratogenicity
were observed.
     In an inhalation study, the potential of β-chloroprene to cause developmental
toxicity in New Zealand white rabbits following gestational exposure was investigated.
The rabbits were exposed to 0, 37, 147, 644 mg/m3 (0, 10, 40 and 175 ppm)
β-chloroprene vapours, 6 hours/day, 7 days/week. Each treatment group consisted of
approximately 15 artificially inseminated females exposed on day 6 through day 28 of
gestation. Body weights were measured throughout the study period, and uterine and
fetal body weights were obtained on day 29 of gestation. Implants were enumerated and
their status recorded and live foetuses were examined for gross, visceral, skeletal, and
soft-tissue craniofacial defects. There were no overt signs of maternal toxicity and the
maternal body weight gain was not affected. Exposure of the pregnant rabbits to
β-chloroprene had no effect on the number of implantations, the mean percentage of live
pups per litter, or on the incidence of resorptions per litter. Foetal body, kidney and liver
β-Chloroprene                                                                                 18
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<pre>    weights (as means of litter means) were not affected, nor the foetal sex ratio. The
    incidence of foetal malformations was not increased by exposure to β-chloroprene. No
    significant alterations in the incidence of total foetal variations or reduced ossifications
    were observed among the exposed groups. The results of the study indicate that
    gestational exposure of New Zealand white rabbits to 10, 40, and 175 ppm
    β-chloroprene did not result in observable toxicity to either the dams or the offspring
    (Mas94). The committee concluded that neither developmental toxicity nor maternal
    toxicity was observed in this study. Therefore, these results were considered
    inconclusive.
    Lactation
    No animal studies concerning effects on lactation were available.
2.4 Overall conclusions
    Sanotskii (San76), Barlow and Sullivan (Bar82) and Koëter et al (Koë89), cited and
    reviewed a number of East European studies in which the effects of β-chloroprene on
    fertility and development were studied. The Dutch Expert Committee on Occupational
    Standards (DECOS) (DEC93), a committee of the Health Council, recommended a
    health-based occupational exposure limit for β-chloroprene based on these East
    European studies. They concluded that there were weak indications for disturbance of
    sexual functions in men and women and for a negative influence on the pregnancy
    (increased number of abortions) after exposure of male workers to β-chloroprene.
    However, the present committee is of the opinion that due to the lack of experimental
    details, it is difficult to evaluate the outcomes of these studies properly. Especially
    information on the exposure levels in human studies and the purity of the β-chloroprene
    used in these studies is insufficient for a adequate evaluation of the results. Moreover, in
    several papers (e.g. Cul78, Bar82, Koë80), it is suggested that due to the presence of
    impurities in the test compound, these studies show a much higher toxicity than studies
    in which precautions are taken to avoid the presence of contaminants. Therefore, the
    committee is of the opinion that a lack of appropriate human data precludes the
    assessment of β-chloroprene for effects on fertility and development.
    In studies with animals in which the purity of the test compound was
    well-controlled, no biologically significant effects on fertility were observed in the
    absence of general toxic effects (Cul78, App79, Mel96). Therefore, the committee is of
    the opinion that the animal data show that no classification is indicated for effects on
    fertility.
    β-Chloroprene                                                                                19
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<pre>In studies with animals, no effects were observed on development by Culik et al and
Mast et al (Cul78, Mas94). However, no maternal effects were observed either and
therefore the committee considers these results as inconclusive. Koëter et al did not
observe effects on development at doses which caused maternal toxicity (Koë80).
Therefore, based on the study of Koëter et al, the committee is of the opinion that
sufficient animal data show that no classification is indicated for effects on
development.
No publications concerning the excretion of ß-chloroprene in human or animal milk
were available. Therefore, a lack of appropriate data precludes the assessment of
β-chloroprene for labelling for effects during lactation.
Proposed classification for fertility
A lack of appropriate human data precludes the assessment of β-chloroprene for fertility
and sufficient animal data show that no classification for effects on fertility is indicated.
Proposed classification for developmental toxicity
A lack of appropriate human data precludes the assement of β-chloroprene for
developmental toxicity and sufficient animal data show that no classification for effects
on development is indicated.
Proposed labelling for effects during lactation
Lack of appropriate data precludes assessment of β-chloroprene for labelling for effects
during lactation.
β-Chloroprene                                                                                 20
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<pre>       References
App79  Appelman LM, Dreef-van der Meulen HC. Reproduction study with ß-chloroprene vapour in rats. Central
       Institute for Nutrition and Food Research 1979, Report No. R 6225.
Bar93  Baranski B. Effects of the workplace on fertility and related reproductive outcomes. Environ Health
       Perspect 1993;101 (Suppl2): 81-90.
Bar82  Barlow SM, Sullivan FM. Reproductive hazards of industrial chemicals. Academic Press, London 1982;
       239-252.
Cul76  Culik R, Kelly DP, Clary JJ. ß-chloroprene (2-chlorobutadiene-1,3) Embryotoxic and teratogenic studies in
       rats. Toxicol Appl Pharmacol 1976; 37:172 (Abstract 194).
Cul78  Culik R, Kelly DP, Clary JJ. Inhalation studies to evaluate the teratogenicand embryotoxic potential of ß-
       chloroprene (2-chlorobutadiene-1,3). Toxicol Appl Pharmacol 1978; 44:81-88.
Dec83  Dutch Expert Committee on Occupational Standards (DECOS). Health-based recommended occupational
       exposure limit for ß-chloroprene. The Hague, The Netherlands: Sdu, 1993; report no RA4/93
IAR99  IARC Monographs on the evaluation of carcinogenic risks to humans. 1999;71:227-250.
Imm78a Immel HR, Willems MI. Dominant lethal assay with ß-chloroprene in male albino rats. Central Institute for
       Nutrition and Food Research, 1978; Report No. R 5625.
Imm78b Immel HR, Willems MI. Dominant lethal assay with ß-chloroprene in male albino rats. Central Institute for
       Nutrition and Food Research, 1978; Report No. R 5762.
Imm78c Immel HR, Willems MI. Dominant lethal assay with ß-chloroprene in male mice. Central Institute for
       Nutrition and Food Research, 1978; Report No. R 5756.
Imm79  Immel HR, Willems MI. Effect of ß-chloroprene exposure of rats on sperm concentration and sperm
       abnormalities. Central Institute for Nutrition and Food Research, 1979; Report No. R 6006.
IUC95  IUCLID Data set 1995, 2-chlorobuta-1,3-diene, CAS No. 126-99-8.
       References                                                                                                 21
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<pre>Koë80 Koëter HBWM, Appelman LM. Inhalation embryotoxicity/teratogenicity studies with ß-chloroprene in rats.
      Central Institute for Nutrition and Food Research, 1980; Report No. R 6387.
Koë89 Koëter HBWM, Dreef-van der Meulen HC, Zielhuis RL, Stijkel A. Schadelijke effecten van chloroprene op
      de voortplanting en nageslacht, anders dan via de inwerking op het erfelijk materiaal; een literatuurstudie.
      Voorburg, Directoraat-Generaal van de Arbeid 1989; S 73-7.
Mas94 Mast TJ, Evanoff JJ, Westerberg RB, Rommereim RL, Weigel RJ. Inhalation development toxicolgy
      studies: developmental toxicity of chloroprene (CAS No. 126-99-8) vapors in New Zealand White Rabbits.
      NTIS Technical Report (NTIS/DE94-012384) 1994 .
Mel96 Melnick RL, Elwell MR, Roycroft JH, Chou BJ, Ragan HA, Miller RA. Toxicity of inhaled chloroprene (2-
      chloro-1,3-butadiene) in F344 rats and B6C3F1 mice. Toxicology 1996; 108:79-91.
NIO77 NIOSH. Criteria Document for a recommended standard: Occupational exposure to Chloroprene.
      Cincinnatti, Ohio 1977 DHEW(NIOSH) Publication No. 77-210.
San76 Sanotskii IV. Aspects of the toxicology of chloroprene: immediate and long-term effects. Environ Health
      Perspect 1976; 17:85-93.
      Literature consulted but not referred to in the text of the report
Dav72 Davtyan RM. Toxicological chatracteristics of the action of chloroprene on the reproductive function of
      male rats. In "Toxicology and Hygiene of the products of Petroleum Chemistry and Petrochemical
      productions". 1972; 95-97. All Union Conference Yaroslave , USSR, 1971. Yaroslavskii Meditsinskii
      Institut.
Dav73 Davtyan RM, Fomenko VN, Andreyeve GP. On the question of the effect of chloroprene on the generating
      function of mammals (males). Toksikologiya Novykh Promyshlennykh Khymicheskikh Veschestv 1973;
      13:58-62.
Mel76 Melik-Alaverdian NO, Kagramanian RG, Kalatarova YC, Krupskaia NK. Reproductive function and sexual
      maturation in third generation rats born from mothers intoxicated with chloroprene. Zhurnal
      Eksperimentalnoi I Klinicheskoi Meditsiny-A N Armyanskoi SSR 1976; 16:54-59.
Mel99 Melnick RL, Sills RC, Portier CJ, Roycroft JH, Chou BJ, Grumbein SL, HA, Miller RA. Multiple organ
      carcinogenicity of inhaled chloroprene (2-chloro-1,3-butadiene) in F344 rats and B6C3F1 mice and
      comparison of dose-response with 1,3-butadiene in mice. Carcinogenesis 1999; 20:867-878.
Nol95 Nolte T, Harleman JH, Jahn W. Histopathology of chemically induced testicular atrophy in rats. Exp Toxic
      Pathol 1995; 47:267-286.
Sal73 Salnikova LS, Fomenko VN. Experimental investigation of the influence produced by chloroprene on the
      embryogenesis. Gig Trud Profzabol 1973; 8: 23-28.
Sal75 Salnikova LS, Fomenko VN. Comparative characterization of the embryonic effect produced produced by
      chloroprene, depending upon the mode of its action with different routes of entrance. Gig Trud Prof-zabol
      1975; 7: 30-33.
San80 Sanotskii IV, Davtyan RM, Glushchenko VI. Study of the reproductive function in men exposed to
      chemicals. Gig Trud Profzabol 1980; 5: 28-32.
      References                                                                                                   22
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<pre>San86 Sanotsky IV, Fomenko VN. Long-term effects of chemicals on the organism. Centre of International
      Projects, GKNT, Moscow, 1986.
She90 Shelby MD. Results of NTP-sponsored mouse cytogenetic studies on 1,3-butadiene, isoprene, and
      chloroprene. Environ Health Perspect 1990; 86:71-73
Sch93 Schwetz BA, Harris MW. Developmental toxicology: Status of the field and contribution of the National
      Toxicology Program. Environ Health Perspect 1993; 100:269-282
Van73 Vanuni SO. Concerning certain problems of the chemical composition of the milk of puerperants working in
      the synthetic rubber plant and living in nearly residences. Zhurnal Eksperimentalnoi i Klinicheskoi
      Meditsiny 1973; 13: 111-114.
Van74 Vanuni SO. Comparative characteristics of individual and total amino acids in breast milk of working
      mothers living in villages at various distances from a synthetic chloroprene rubber combine. Zhurnal
      Eksperimentalnoi i Klinicheskoi Meditsiny 1974; 14: 96-101.
Vol76 Volkova ZA. On the substantiation of the maximum permissible concentrations for chloroprene in the air of
      the working place. Gig Tr Zabol 1976; 20:31-36.
      References                                                                                                23
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<pre>A The committee
B Comments on the public draft
C Directive (93/21/EEC) of the European Community
D Fertility and developmental toxicity studies
E Abbreviations
  Annexes
                                                  24
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<pre>Annex A
      The committee
      •  BJ Blaauboer, chairman
         Toxicologist, Institute for Risk Assessment Sciences, Utrecht
      •  AM Bongers, advisor
         Ministry of Social Affairs and Employment, Den Haag
      •  HFP Joosten
         Toxicologist, NV Organon, Department of Toxicology and Drug Disposition, Oss
      •  D Lindhout
         professor of Medical Genetics, paediatrician, UMC, Utrecht
      •  JHJ Copius Peereboom-Stegeman
         Toxicologist, Catholic University Nijmegen, Nijmegen
      •  AH Piersma
         Reproductive toxicologist, National Institute of Public Health and the Environment,
         Bilthoven
      •  N Roeleveld
         Epidemiologist, Catholic University Nijmegen, Nijmegen
      •  DH Waalkens-Berendsen
         Reproductive toxicologist, TNO Nutrition and Food Research, Zeist
      •  PJJM Weterings
         Toxicologist, Weterings Consultancy BV, Rosmalen
      •  ASAM van der Burght, scientific secretary
         Health Council of the Netherlands, Den Haag
      The committee                                                                          25
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<pre>The first draft of the present document was prepared by K Kruse and JAGM van Raaij
of OpdenKamp Registration and Notification, the Hague, by contract with the Ministry
of Social Affairs and Employment.
Secretarial assistance: RA Aksel.
Lay-out: M Javanmardi/J van Kan.
The committee                                                                        26
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<pre>Annex B
      Comments on the public draft
      A draft of the present report was released in 2002 for public review. No persons and
      organisations have commented on the draft review.
      Comments on the public draft                                                         27
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<pre>Annex C
      Directive (93/21/EEC) of the European
      Community
      4.2.3         Substances toxic to reproduction
      4.2.3.1        For the purposes of classification and labelling and having regard to the present
                    state of knowledge, such substances are divided into 3 categories:
      Category 1:
      Substances known to impair fertility in humans
      There is sufficient evidence to establish a causal relationship between human exposure to the substance and
      impaired fertility.
      Substances known to cause developmental toxicity in humans
      There is sufficient evidence to establish a causal relationship between human exposure to the substance and
      subsequent developmental toxic effects in the progeny.
      Directive (93/21/EEC) of the European Community                                                             28
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<pre>Category 2:
Substances which should be regarded as if they impair fertility in humans:
There is sufficient evidence to provide a strong presumption that human exposure to the substance may
result in impaired fertility on the basis of:
•    Clear evidence in animal studies of impaired fertility in the absence of toxic effects, or, evidence of
     impaired fertility occurring at around the same dose levels as other toxic effects but which is not a sec-
     ondary non-specific consequence of the other toxic effects.
•    Other relevant information.
Substances which should be regarded as if they cause developmental toxicity to humans:
There is sufficient evidence to provide a strong presumption that human exposure to the substance may
result in developmental toxicity, generally on the basis of:
•    Clear results in appropriate animal studies where effects have been observed in the absence of signs of
     marked maternal toxicity, or at around the same dose levels as other toxic effects but which are not a
     secondary non-specific consequence of the other toxic effects.
•    Other relevant information.
 Category 3:
Substances which cause concern for human fertility:
Generally on the basis of:
•    Results in appropriate animal studies which provide sufficient evidence to cause a strong suspicion of
     impaired fertility in the absence of toxic effects, or evidence of impaired fertility occurring at around
     the same dose levels as other toxic effects, but which is not a secondary non-specific consequence of
     the other toxic effects, but where the evidence is insufficient to place the substance in Category 2.
•    Other relevant information.
Substances which cause concern for humans owing to possible developmental toxic effects:
Generally on the basis of:
•    Results in appropriate animal studies which provide sufficient evidence to cause a strong suspicion of
     developmental toxicity in the absence of signs of marked maternal toxicity, or at around the same dose
     levels as other toxic effects but which are not a secondary non-specific consequence of the other toxic
     effects, but where the evidence is insufficient to place the substance in Category 2.
•    Other relevant information.
Directive (93/21/EEC) of the European Community                                                                 29
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<pre>4.2.3.2       The following symbols and specific risk phrases apply:
Category 1:
For substances that impair fertility in humans:
T; R60: May impair fertility
For substances that cause developmental toxicity:
T; R61: May cause harm to the unborn child
Category 2:
For substances that should be regarded as if they impair fertility in humans:
T; R60: May impair fertility
For substances that should be regarded as if they cause developmental toxicity in humans:
T; R61: May cause harm to the unborn child.
Category 3:
For substances which cause concern for human fertility:
Xn; R62: Possible risk of impaired fertility
For substances which cause concern for humans owing to possible developmental toxic effects:
Xn; R63: Possible risk of harm to the unborn child.
4.2.3.3       Comments regarding the categorisation of substances toxic to reproduction
Reproductive toxicity includes impairment of male and female reproductive functions or capacity and the
induction of non-inheritable harmful effects on the progeny. This may be classified under two main
headings of 1) Effects on male or female fertility, 2) Developmental toxicity.
1    Effects on male or female fertility, includes adverse effects on libido, sexual behaviour, any aspect of
     spermatogenesis or oogenesis, or on hormonal activity or physiological response which would interfere
Directive (93/21/EEC) of the European Community                                                               30
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<pre>       with the capacity to fertilise, fertilisation itself or the development of the fertilised ovum up to and
       including implantation.
2      Developmental toxicity, is taken in its widest sense to include any effect interfering with normal
       development, both before and after birth. It includes effects induced or manifested prenatally as well as
       those manifested postnatally. This includes embrytoxic/fetotoxic effects such as reduced body weight,
       growth and developmental retardation, organ toxicity, death, abortion, structural defects (teratogenic
       effects), functional defects, peri/postnatal defects, and impaired postnatal, mental or physical develop-
       ment up to and including normal pubertal development.
Classification of chemicals as toxic to reproduction is intended to be used for chemicals which have an
intrinsic or specific property to produce such toxic effects. Chemicals should not be classified as toxic to
reproduction where such effects are solely produced as a non-specific secondary consequence of other toxic
effects. Chemicals of most concern are those which are toxic to reproduction at exposure levels which do
not produce other signs of toxicity.
The placing of a compound in Category 1 for effects on Fertility and/or Developmental Toxicity is done on
the basis of epidemiological data. Placing into Categories 2 or 3 is done primarily on the basis of animal
data. Data from in vitro studies, or studies on avian eggs, are regarded as ‘supportive evidence’ and would
only exceptionally lead to classification in the absence of in vivo data.
In common with most other types of toxic effect, substances demonstrating reproductive toxicity will be
expected to have a threshold below which adverse effects would not be demonstrated. Even when clear
effects have been demonstrated in animal studies the relevance for humans may be doubtful because of the
doses administrated, for example, where effects have been demonstrated only at high doses, or where
marked toxicokinetic differences exist, or the route of administration is inappropriate. For these or similar
reasons it may be that classification in Category 3, or even no classification, will be warranted.
Annex V of the Directive specifies a limit test in the case of substances of low toxicity. If a dose level of at
least 1000 mg/kg orally produces no evidence of effects toxic to reproduction, studies at other dose levels
may not be considered necessary. If data are available from studies carried out with doses higher than the
above limit dose, this data must be evaluated together with other relevant data. Under normal circumstances
it is considered that effects seen only at doses in excess of the limit dose would not necessarily lead to
classification as Toxic to Reproduction.
Effects on fertility
For the classification of a substance into Category 2 for impaired fertility, there should normally be clear
evidence in one animal species, with supporting evidence on mechanism of action or site of action, or
chemical relationship to other known antifertility agents or other information from humans which would
Directive (93/21/EEC) of the European Community                                                                  31
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<pre>lead to the conclusion that effects would be likely to be seen in humans. Where there are studies in only one
species without other relevant supporting evidence then classification in Category 3 may be appropriate.
Since impaired fertility may occur as a non-specific accompaniment to severe generalised toxicity or where
there is severe inanition, classification into Category 2 should only be made where there is evidence that
there is some degree of specificity of toxicity for the reproductive system. If it was demonstrated that
impaired fertility in animal studies was due to failure to mate, then for classification into Category 2, it
would normally be necessary to have evidence on the mechanism of action in order to interpret whether any
adverse effect such as alteration in pattern of hormonal release would be likely to occur in humans.
Developmental toxicity
For classification into Category 2 there should be clear evidence of adverse effects in well conducted studies
in one or more species. Since adverse effects in pregnancy or postnatally may result as a secondary
consequence of maternal toxicity, reduced food or water intake, maternal stress, lack of maternal care,
specific dietary deficiencies, poor animal husbandry, intercurrent infections, and so on, it is important that
the effects observed should occur in well conducted studies and at dose levels which are not associated with
marked maternal toxicity. The route of exposue is also important. In particular, the injection of irritant
material intraperitoneally may result in local damage to the uterus and its contents, and the results of such
studies must be interpreted with caution and on their own would not normally lead to classification.
Classification into Category 3 is based on similar criteria as for Category 2 but may be used where the
experimental design has deficiencies which make the conclusions less convincing, or where the possibility
that the effects may have been due to non-specific influences such as generalised toxicity cannot be
excluded.
In general, classification in category 3 or no category would be assigned on an ad hoc basis where the only
effects recorded are small changes in the incidences of spontaneous defects, small changes in the
proportions of common variants such as are observed in skeletal examinations, or small differences in
postnatal developmental assessments.
Effects during Lactation
Substances which are classified as toxic to reproduction and which also cause concern due to their effects on
lactation should in addition be labelled with R64 (see criteria in section 3.2.8).
For the purpose of classification, toxic effects on offspring resulting only from exposure via the breast milk,
or toxic effects resulting from direct exposure of children will not be regarded as ‘Toxic to Reproduction’,
unless such effects result in impaired development of the offspring.
Directive (93/21/EEC) of the European Community                                                                 32
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<pre>Substances which are not classified as toxic to reproduction but which cause concern due to toxicity when
transferred to the baby during the period of lactation should be labelled with R64 (see criteria in section
3.2.8). This R-phrase may also be appropriate for substances which affect the quantity or quality of the milk.
R64 would normally be assigned on the basis of:
a    toxicokinetic studies that would indicate the likelihood that the substance would be present in poten-
     tially toxic levels in breast milk, and/or
b    on the basis of results of one or two generation studies in animals which indicate the presence of
     adverse effects on the offspring due to transfer in the milk, and/or
c    on the basis of evidence in humans indicating a risk to babies during the lactational period.
Substances which are known to accumulate in the body and which subsequently may be released into milk
during lactation may be labelled with R33 and R64.
Directive (93/21/EEC) of the European Community                                                                33
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<pre>Annex D
      Fertility and developmental toxicity
      studies
      See tables on the next pages.
      Fertility and developmental toxicity studies 34
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<pre>Table 1.1 Fertility studies with b-chloroprene in animals.
authors   species      experimental         dose and route  general    effects on reproductive         remarks
                       period/design                        toxicity   organs/effects on reproduction
San76     C57BL/       Dominant lethal      0, 0.05,0.13,              Fertility unaffected. Increase  Validity of the results
          6 mice       test.                1.85 mg/m³                 in total embryonic mortality    concerning the pre- and
          8-11         Two months           (inh)                      from 19% (controls) to 33, 36   post-implantation losses
          males/       exposure and then                               and 42% at 0.05, 0.13 and       questionable due to
          group        mating to untreated                             1.85 mg/m3, respectively        limitations of the
                       females.                                                                        experimental methods.
San76     C57BL/       Dominant lethal      0, 0.064,0.32,             Fertility unaffected. Increase  Validity of the results
          6 mice       test.                3.5 mg/m³ (inh)            in total embryonic mortality    concerning the pre- and
          14-15        Two months                                      from 29% (controls) to 52, 50   post-implantation losses is
          males/       exposure and then                               and 63% at 0.064, 0.32 and      questionable due to
          group        mating to untreated                             3.5 mg/m³, respectively         limitations of the
                       females.                                                                        experimental methods
San76     White        Dominant lethal      0, 0.057, 0.14             The embryonic death rate was
          rats10       test.                mg/m³ (inh)                increased from 10% at 0 and
          males/       2.5 months                                      0.057 mg/m³ to 21% at 0.14
          group        exposure and then                               mg/m³. The majority of deaths
                       mating to untreated                             occurred after implantation.
                       females.
Imm78a    Wistar       6 hours/day for 5    0, 180, 360 mg/            No adverse effects on fertility β-Chloroprene freshly
Imm78b    rats         days. Thereafter     m³ (inh)                   ( pregnancy, numbers of         distilled under nitrogen
          12           mating with 2                                   corpora lutea, live and dead
          males/       untreated females/                              implants.
          group        week for 8 weeks.                               No effect on survival of the
                       Sacrifice 15 days                               offspring
                       after mid-week of
                       mating
Imm78c    Swiss        2 weeks, 6 hours/    0, 36, 360 mg/  At 360     In survivors no effects on      One male from the highest
          mice         day, 5 days/week.    m³              mg/m³      fertility or embryomortality    dose group withdrawn from
          12           Thereafter mating    (inh)           8/12 males                                 study due to poor
          males/       with untreated                       died                                       reproductive performance
          group        females for 8                        during                                     β-Chloroprene freshly
                       weeks.                               first 3                                    distilled under nitrogen
                                                            days of
                                                            exposure
             Fertility and developmental toxicity studies                                                                         35
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<pre>Table 1.2 Fertility studies with ß-chloroprene in animals.
authors species          experimental        dose and route  general toxicity      effects on reproductive       remarks
                         period/design                                             organs/effects on
                                                                                   reproduction
Imm79 Wistar rats/       3 or 6 months, 6    0, 10, 33, 100                        No dose related changes in
         group           hours/day, 5 days/  ppm                                   sperm concentration or
                         week                (inh)                                 morphological
                                                                                   abnormalities
Cul78    Charles         22 consecutive      0, 90 mg/m³                           No adverse effects on         The β-chloroprene
         River-CD        days, 4 hours/day (inh)                                   fertility, litter size and    in the study had a
         rats.           Thereupon mating                                          postnatal survival of the     purity of 99.9% and
         5 males/        with untreated                                            offspring                     contained less than
         group           females (3 females/                                                                     50 ppm dimers.
                         male/week) during
                         8 weeks
App79    Wistar rats     2-generation study, 0, 36, 119, 360                       No effects on fertility in    The β-chloroprene
         25 females/     13 weeks, 6 hours/ mg/m³                                  both generations              in this study was
         group           day, 5 days/week. (inh)                                                                 freshly purified
App79    Wistar rats     2-generation study, 0, 36, 119, 360 F0 generation         F0 generation:                The β-chloroprene
         F0              F0 generation: 13 mg/m³             At 360 mg/m³          no effects on fertility of F0 in this study was
         generation:     weeks, 6 hours/day, (inh)           reduction in body     males.                        freshly purified.
         25 males/       5 days/week.                        weight gain           No effects on intra-uterine
         group.          Thereupon mating                                          mortality and litter size.
                         with untreated                                            No histopathological
                         females.                                                  abnormalities in testicles
                                                             F1 generatioin
         F1              F1 generation:                      At 119 and 360 mg/
         generation:     10 weeks from                       m³ reduction in body  F1 generation:
         20/sex/group week 4 after birth.                    weight gain.          No effects on intra-uterine
                                                             In females increase   mortality, litter size, post
                                                             in relative weight of natal death and general
                                                             liver and ovaries     condition of the offspring.
               Fertility and developmental toxicity studies                                                                         36
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<pre>Table 1.3 Fertility studies wit ß-chloroprene in animals.
authors species        experimenta dose and       general toxicity         effects on reproductive      remarks
                       l period/      route                                organs/effects on
                       design                                              reproduction
Mel96 F344/N rats, 13 weeks, 6 0, 5, 12,          One male in the 200      At 200 ppm a significant     The β-chloroprene in the
         10/sex/       hours/day, 5 32, 80, 200   ppm dose group died on   reduction in sperm motility. study had a purity of 97.9%
         group         days/week      ppm         day 2 of exposure.       No atrophy of the testes.    and contained less than
                                      (inh)       Increase in mean kidney  No effects on male           0.2% chloroprene dimers.
                                                  weight in males (200     reproductive parameters.     The peroxide content was
                                                  ppm) and females (80,    No interference with oestral less than 0.2 mequiv/kg
                                                  200 ppm).                cyclicity in females.        chloroprene
                                                  At 80 and 200 ppm
                                                  degeneration and
                                                  metaplasia of the
                                                  olfactory epithelium.
                                                  At 200 ppm anemia and
                                                  hepatocellular necrosis.
Mel96 B6C3F1 rats 13 weeks, 6 0, 5, 12,           At 80 ppm slightly       No atrophy of the testes.    The β-chloroprene in the
         10/sex/       hours/day, 5 32, 80 ppm reduced body weight         No effects on male           study had a purity of 97.9%
         group         days/week      (inh)       gain.                    reproductive parameters.     and contained less than
                                                                           No interference with oestral 0.2% chloroprene dimers.
                                                                           cyclicity in females         The peroxide content was
                                                                                                        less than 0.2 mequiv/kg
                                                                                                        chloroprene
              Fertility and developmental toxicity studies                                                                        37
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<pre>Table 2.1 Developmental toxicity studies with β-chloroprene in animals
authors species            experiment dose and      maternal toxicity developmental toxicity                                   rem-
                           al period/ route                                                                                    arks
                           design
Cul78    Charles River-    4 hours/   0 , 3.6, 36,                    No effects on litter size, average number of
         CD rats           day during 90 mg/m³                        implantation sites/litter, and preimplantation losses.
         43-48 pregnant    GD 1-12, (inh)
         females/group     evaluation
                           of
                           embryotoxi
                           city
Cul78    Charles River-    4 hours/   0 , 3.6, 36,                    No effects on litter size, average number of
         CD rats19-24      day during 90 mg/m³                        implantation sites/litter, and preimplantation losses.
         pregnant          GD 3-20, (inh)                             At 36 mg/m³ a slight increase in number of dams with
         females/group     evaluation                                 resorptions (statistically significant but not
                           of                                         tocicological relevant)
                           teratology                                 At 90 mg/m³ a slight increase in average foetal body
                                                                      weight (statistically significant).
                                                                      At 36 and 90 mg/m³ increased crown-rump length
                                                                      (statistically significant). No major external, skeletal
                                                                      or soft tissue malformations.
Koë80 Wistar rats 7        6 hours/   0, 36, 90,    At 90, 270 and    At 270 and 360 mg/m³ some foetal growth depression
         pregnant          day during 270, 360      360 mg/m³         (not biologically significant). No signs of
         females/group     GD 6-16    mg/m³ (inh) reduction in        embryotoxicty or teratogenicity.
                                                    growth and food
                                                    intake.
Koë80 Wistar rats 30       6 hours/   0, 36, 90,    At 90, 270 and    Visceral and skeletal effects evaluated. At 270 and
         pregnant          day during 270, 360      360 mg/m³         360 mg/m³ some foetal growth depression (not
         females/group     GD 4-16    mg/m³ (inh) reduction in        biologically significant). No signs of embryotoxicty
                                                    growth and food   or teratogenicity.
                                                    intake.
Mas94 New Zealand          6 hours/   0, 10, 40,    No overt signs of No effect on number of implantations, mean
         White rabbits15   day, 7     175 ppm       maternal          percentage of live pups/litter, or incidence of
         artificially      days/week (inh)          toxicity. No      resorptions/litter. No increase in foetal malformations,
         inseminated       during GD                effects on change total foetal variations or reduced ossifications. No
         females/group     6 -28                    in maternal body  effects on foetal body, kidney and liver weights or on
                                                    weight            sex ratio.
               Fertility and developmental toxicity studies                                                                        38
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<pre>Annex E
      Abbreviations
      Abbreviations used:
      bw        body weight
      d         day
      F         female(s)
      i.p.      intraperitoneal
      i.v.      intravenous
      M         male(s)
      n         number
      NOAEL     no adverse effect level
      OECD      Organisation for Economic Cooperation and Development
      PN        postnatal
      Abbreviations                                                   39
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