<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>4-Vinylcyclohexene diepoxide
Evaluation of the carcinogenicity and genotoxicity
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<pre></pre>

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<pre>Gezondheidsraad                                          Vo o r z i t t e r
Health Council of the Netherlands
Aan de minister van Sociale Zaken en Werkgelegenheid
Onderwerp               : Aanbieding advies 4-Vinylcyclohexene diepoxide
Uw kenmerk              : DGV/MBO/U-932542
Ons kenmerk             : U-5140/JR/pg/246-M12
Bijlagen                :1
Datum                   : 1 april 2008
Geachte minister,
Graag bied ik u hierbij het advies aan over de kankerverwekkendheid van 4-vinylcyclo-
hexene diepoxide. Het maakt deel uit van een uitgebreide reeks waarin kankerverwekkende
stoffen worden geclassificeerd volgens richtlijnen van de Europese Unie. Het gaat om stof-
fen waaraan mensen tijdens de beroepsmatige uitoefening kunnen worden blootgesteld.
     Het advies is opgesteld door een vaste subcommissie van de Commissie Gezondheid en
beroepsmatige blootstelling aan stoffen (GBBS), de Subcommissie Classificatie van carci-
nogene stoffen. Het advies is voorgelegd aan de Commissie GBBS en vervolgens getoetst
door de Beraadsgroep Gezondheid en omgeving van de Gezondheidsraad.
Ik heb dit advies vandaag ter kennisname toegezonden aan de minister van Volksgezond-
heid, Welzijn en Sport en de minister van Volkshuisvesting, Ruimtelijke Ordening en
Milieubeheer.
Hoogachtend,
prof. dr. J.A. Knottnerus
Bezoekadres                                                                 Postadres
Parnassusplein 5                                                            Postbus 16052
2 5 11 V X D e n          Haag                                              2500 BB Den            Haag
Te l e f o o n ( 0 7 0 ) 3 4 0 6 6 3 1                                      Te l e f a x ( 0 7 0 ) 3 4 0 7 5 2 3
E - m a i l : j o l a n d a . r i j n k e l s @ g r. n l                    w w w. g r. n l
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<pre></pre>

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<pre>4-Vinylcyclohexene diepoxide
Evaluation of the carcinogenicity and genotoxicity
Subcommittee on the classification of carcinogenic substances of the
Dutch Expert Committee on Occupational Standards,
a committee of the Health Council of the Netherlands
to:
the Minister of Social Affairs and Employment
No. 2008/03OSH, The Hague, April 1, 2008
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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
22, 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 & Food Quality. 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 gov-
ernment 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.
                 The Health Council of the Netherlands is a member of the European
                 Science Advisory Network for Health (EuSANH), a network of science
                 advisory bodies in Europe.
                 The Health Council of the Netherlands is a member of the International Network
                 of Agencies for Health Technology Assessment (INAHTA), an international
                 collaboration of organisations engaged with health technology assessment.
  I NA HTA
This report can be downloaded from www.healthcouncil.nl.
Preferred citation:
Health Council of the Netherlands. 4-Vinylcyclohexene diepoxide; Evaluation of
the carcinogenicity and genotoxicity. The Hague: Health Council of the Nether-
lands, 2008; publication no. 2008/03OSH.
all rights reserved
ISBN: 978-90-5549-688-4
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<pre>    Contents
    Samenvatting 9
    Executive summary 11
1   Scope 13
1.1 Background 13
1.2 Committee and procedures 13
1.3 Data 14
2   General information 15
2.1 Identity and physico-chemical properties 15
2.2 IARC classification 16
3   Carcinogenicity 17
3.1 Observations in humans 17
3.2 Carcinogenicity studies in animals 17
4   Mutagenicity and genotoxicity 21
4.1 In vitro assays 21
4.2 In vivo assays 22
4.3 Additional information and carcinogenic mechanism 22
    Contents                                             7
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<pre>5   Classification 23
5.1 Evaluation of data on carcinogenicity and genotoxicity 23
5.2 Recommendation for classification 24
    References 25
    Annexes 27
A   Request for advice 29
B   The committee 31
C   Comments on the public review draft 33
D   IARC Monograph 35
E   Carcinogenic classification of substances by the committee 37
F   Guideline 93/21/EEG of the European Union 39
8   4-Vinylcyclohexene diepoxide
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<pre>Samenvatting
Op verzoek van de minister van Sociale Zaken en Werkgelegenheid evalueert en
beoordeelt de Gezondheidsraad de kankerverwekkende eigenschappen van stof-
fen waaraan mensen tijdens het uitoefenen van hun beroep kunnen worden bloot-
gesteld. De evaluatie en beoordeling worden verricht door de subcommissie
Classificatie van Carcinogene Stoffen van de Commissie Gezondheid en
Beroepsmatige Blootstelling aan Stoffen van de Raad, hierna kortweg aangeduid
als de commissie. In het voorliggende advies neemt de commissie 4-vinylcyclo-
hexeen diepoxide onder de loep. De stof wordt gebruikt als verdunner voor
andere diepoxiden en voor epoxyharsen.
Op basis van de beschikbare gegevens leidt de commissie af dat 4-vinylcyclo-
hexene diepoxide beschouwd moet worden als kankerverwekkend voor de mens.
Dit is vergelijkbaar met een classificatie in categorie 2 volgens de richtlijnen van
de Europese Unie. De commissie is verder van mening dat de stof een stochas-
tisch genotoxisch werkingsmechanisme heeft.
Samenvatting                                                                         9
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<pre>10 4-Vinylcyclohexene diepoxide</pre>

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<pre>Executive summary
At request of the Minister of Social Affairs and Employment, the Health Council
of the Netherlands evaluates and judges the carcinogenic properties of sub-
stances to which workers are occupationally exposed. The evaluation is per-
formed by the subcommittee on Classifying Carcinogenic Substances of the
Dutch Expert Committee on Occupational Standards of the Health Council, here-
after called the committee. In this report, the committee evaluated 4-vinylcyclo-
hexene diepoxide. The agent is used as a diluent for other diepoxides and for
epoxy resins
Based on the available information, the committee is of the opinion that 4-vinyl-
cyclohexene diepoxide should be considered as carcinogenic to humans. This
recommendation is comparable to the EU classification in category 2. The com-
mittee is furthermore of the opinion that 4-vinylcyclohexene diepoxide acts by a
stochastic genotoxic mechanism.
Executive summary                                                                 11
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<pre>12 4-Vinylcyclohexene diepoxide</pre>

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<pre>Chapter 1
        Scope
1.1     Background
        In the Netherlands a special policy is in force with respect to occupational use
        and exposure to carcinogenic substances. Regarding this policy, the Minister of
        Social Affairs and Employment has asked the Health Council of the Netherlands
        to evaluate the carcinogenic properties of substances, and to propose a classifica-
        tion (see Annex A). The assessment and the proposal for a classification are
        expressed in the form of standard sentences (see Annex E). The criteria used for
        classification are partly based on an EU-directive (see Annex F). In addition to
        classifying substances, the Health Council also assesses the genotoxic properties
        of the substance in question.
        This report contains the evaluation of the carcinogenicity of 4-vinylcyclohexene
        diepoxide.
1.2     Committee and procedures
        The evaluation is performed by the subcommittee on Classifying Carcinogenic
        Substances of the Dutch Expert Committee on Occupational Standards of the
        Health Council, hereafter called the committee. The members of the committee
        are listed in Annex B. The first draft was prepared by I.A. van de Gevel and M.I.
        Willems, from the Department of Occupational Toxicology of the TNO Nutrition
        Scope                                                                               13
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<pre>    and Food Research, by contract with the Ministry of Social Affairs and Employ-
    ment.
         In 2007 the President of the Health Council released a draft of the report for
    public review. The individuals and organisations that commented on the draft are
    listed in Annex C. The committee has taken these comments into account in
    deciding on the final version of the report.
1.3 Data
    The evaluation and recommendation of the committee is standardly based on sci-
    entific data, which are publicly available. The starting points of the committees’
    reports are, if possible, the monographs of the International Agency for Research
    on Cancer (IARC). This means that the original sources of the studies, which are
    mentioned in the IARC-monograph, are reviewed only by the committee when
    these are considered most relevant in assessing the carcinogenicity and genotox-
    icity of the substance in question. In the case of 4-vinylcyclohexene diepoxide,
    such an IARC-monograph is available, of which the summary and conclusion of
    IARC is inserted in Annex D.
         More recently published data were retrieved from the online databases Med-
    line, Toxline, Chemical Abstracts, and RTECS. The last updated online search
    was in June 2007. The new relevant data were included in this report.
14  4-Vinylcyclohexene diepoxide
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<pre>Chapter 2
        General information
2.1     Identity and physico-chemical properties
        4-Vinylcyclohexene diepoxide is used as a diluent for other diepoxides and for
        epoxy resins derived from bisphenol A and epichlorohydrin.1-3
             Below is given the identity and some of its physical and chemical proper-
        ties.1-3
        Chemical name         :  4-vinylcyclohexene diepoxide
        CAS registry number   :  106-87-6
        EINECS number         :  203-437-7
        IUPAC name            :  3-(Epoxyethyl)-7-oxabicyclo[4.1.0]heptane
        Synonyms              :  1,2-Epoxy-4-(epoxyethyl)cyclohexane; 1-(epoxyethyl)-3,4-epoxycy-
                                 clohexane; 3-(1,2-epoxyethyl)-7-oxabicyclo[4.1.0]heptane; vinylcy-
                                 clohexene diepoxide; 4-vinyl-1-cyclohexene diepoxide; 4-vinyl-1,2-
                                 cyclohexene diepoxide; 4-vinylcyclohexene dioxide; 1-vinyl-3-cyclo-
                                 hexene dioxide; 4-vinyl-1-cyclohexene dioxide
        Description           :  Clear, colourless or pale yellow liquid
        Molecular formula     :  C8H12O2
        Structure             :
        General information                                                                          15
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<pre>    Molecular weight        : 140.18
    Melting point           : -55 °C
    Boiling point           : 227 °C
    Relative vapour density : 1.0986 at 20 °C / 4 °C
    Vapour pressure         : 13 Pa at 20 °C
    Log Pow                 : 3.38
    Solubility              : Very soluble in water
    Stability               : Flash-point, 110 °C in open cup
    Conversion factors      : 1 ppm = 5.82 mg/m3 air
    (20 °C)                   1 mg/m3 = 0.17 ppm
    EU Risk phrases         : R23/24/25: toxic by inhalation, in contact with skin and if swallowed
                              R68: possible risk for irreversible effects
                              T: toxic
2.2 IARC classification
    In 1994, IARC summarized that there is inadequate evidence in humans for the
    carcinogenicity of 4-vinylcyclohexene diepoxide, but that there is sufficient evi-
    dence in experimental animals.2 Therefore, IARC concluded that the agent is
    possibly carcinogenic to humans (Group 2B).
16  4-Vinylcyclohexene diepoxide
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<pre>Chapter 3
        Carcinogenicity
3.1     Observations in humans
        No data were available on the carcinogenicity of 4-vinylcyclohexene diepoxide
        in humans.
3.2     Carcinogenicity studies in animals
        The National Toxicology Program performed a carcinogenicity study in rats and
        mice.3,4 Groups of 60 male and 60 female F344/N rats and B6C3F1 mice received
        the agent by topical application at doses of 0 (vehicle), 15, or 30 mg/animal
        (rats), and 0 (vehicle), 2.5, 5, or 10 mg/animal (mice), five days per week for 105
        weeks. At month 15, ten animals from each group were sacrificed for interim his-
        topathological examination.
            The survival in rats at the end of the study was very low for all groups,
        including the vehicle controls. No significant differences in survival were
        observed among any groups of males. However, survival in the high-dose female
        group was significantly lower than in vehicle female group after day 648; the
        low-dose female group had significantly lower survival between days 637 and
        715.
            Regarding tumour development, increased incidences of skin tumours at the
        site of application were observed in male and female rats in all dose groups.
        Details are shown in Table 3.1. No other treatment related tumours were
        Carcinogenicity                                                                     17
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<pre>Table 3.1 Survival and skin tumour incidences of F344 rats receiving 4-vinylcyclohexene diepoxide by topical application for
two years.3,4
                                              Overall rates                              Terminal ratesa
Dose (mg/rat)                                 0             15          30               0            15       30
Survival
males                                         7/50          8/50        4/50
females                                       27/50         23/50       15/50
Tumour incidences
males
  skin: basal cell adenoma or                 0/50          1/50        6/50             0/7          0/8      1/4
  carcinoma
  skin: squamous cell papilloma               0/50          3/50        6/50*            0/7          1/8      0/4
  skin: squamous cell carcinoma               0/50          33/50**     36/50**          0/7          8/8      4/4
females
  skin: basal cell carcinoma                  0/50          3/50        4/50*            0/27         2/23     2/15
  skin: squamous cell carcinoma               0/50          16/50**     34/50**          0/27         14/23    15/15
a
     Terminal rates are tumour incidence rates in animals, which were still alive at 105 weeks.
*    p<0.05 versus vehicle control; ** p<0.01 versus vehicle control.
              observed. At the site of application, the treated animals had also significantly
              increased nonneoplastic skin lesions, such as acanthosis and sebaceous gland
              hypertrophy.
                    In male and female mice, survival of the mid- and the high-dose groups was
              significantly lowered compared to vehicle controls. All females in the high-dose
              group were killed at week 85.
                    As in rats, 4-vinylcyclohexene diepoxide induced squamous cell carcinomas
              at the site of application in male and female mice, as shown in Table 3.2. No
              other treatment related skin tumours were observed. However, nonneoplastic
              skin lesions, such as acanthosis, hyperkeratosis and necrotizing inflammation
              (mid and high dose groups), were found to be significantly increased in both
              male and female mice at all dose groups. Furthermore, in treated female mice a
              significant increase of number of animals with ovarian tumours were observed
              compared to vehicle controls (see table 3.2). Also in female mice, an increased
              incidence of lung tumours in the mid-dose group was found, but not in the high-
              dose group. No other treatment related tumours were found in any of the exposed
              groups.
18            4-Vinylcyclohexene diepoxide
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<pre>Table 3.2 Survival and tumour incidences of B6C3F1 mice receiving 4-vinylcyclohexene diepoxide by topical application for
two years.3,4
                                             Overall rates                               Terminal ratesa
Dose (mg/mouse)                              0         2.5       5          10           0         2.5    5      10
Survival
males                                        38/50     35/50     4/50       0/50
females                                      30/50     31/50     15/50      12/50§
Tumour incidences
males
  skin: squamous cell carcinoma              0/50      15/50** 39/50** 42/50**           0/38      10/35  4/4    0/0
females
  skin: squamous cell carcinoma              0/50      6/50*     37/50** 41/50**         0/30      3/31   15/15  0/0
  ovary: luteoma, granulosa cell tumour,     1/50      0/49      17/49* 18/50*           1/30      0/31   7/14   0/0
  benign mixed tumour, or malignant
  cell tumour
  lung: alveolar/bronchiolar adenoma or      4/50      9/50      11/50*     7/50         3/30      7/31   4/15   0/0
  carcinoma
a
     Terminal rates are tumour incidence rates in animals, which were still alive at 105 weeks.
§    Number of animals alive at week 85. * p<0.05 versus vehicle control; ** p<0.01 versus vehicle control.
              Tennant et al. (1996) evaluated the carcinogenicity of 4-vinylcyclohexene diep-
              oxide in a transgenic mouse bioassay.5 In that assay, male and female heterozy-
              gous p53-deficient C57BL/6 mice were used. These knock-out mice are
              susceptible for tumour development, due to a loss of expression of the p53
              tumour suppressor gene. The agent was topically applied at doses of 0, 12.5, or
              25 mg/animal, five times per week for 24 weeks. The same type of squamous cell
              tumours were observed in the treated transgenic mice as in normal mice of the
              two-year study of the National Toxicology Program3, whereas in non-treated
              transgenic animal no such tumours were observed (tumour incidence: nontreated,
              0%; 12.5 mg/mouse, 20-28%; 25 mg/mouse, 30-40%). Further details are not
              given.
                  Yamamoto et al. (1998) reported of a transgenic mouse bioassay for rapid
              carcinogenicity testing.6 This time rasH2 (CB6F1) mice were used carrying the
              human prototype c-Ha-ras gene. In various human and animal tumours ras genes
              are activated by point mutations. Therefore, this transgenic mouse line should be
              vulnerable to developing tumours. To the dorsal skin of the transgenic and non-
              transgenic mice the agent was applied at doses of 5 or 10 mg/kg bw, five times
              per week for 24 weeks. 4-Vinylcyclohexene diepoxide induced skin papillomas
              around the site of application 26 weeks after the first administration of the agent;
              in the high-dose groups, the incidence of skin papillomas was significantly
              Carcinogenicity                                                                                           19
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<pre>   higher in female transgenic mice than in the vehicle treated transgenic mice. In
   both male and female transgenic mice of the high-dose group, the incidence of
   skin papillomas was significantly higher than in the corresponding non-trans-
   genic mice. Furthermore, non-significant increases in incidences of forestomach
   papilloma, thymic lymphoma, and lung adenoma were observed in transgenic
   mice, but not in the corresponding non-transgenic groups. No skin squamous cell
   carcinomas, or spleen hemangiosarcomes were found in non-transgenic groups,
   whereas in transgenic groups these were observed. Further details on study
   design and results are not given.
   The Working Group of IARC also reported of three skin application carcinoge-
   nicity studies, which had serious shortcomings in study design and reporting of
   the results.2 For this reason the committee did not evaluate them.
20 4-Vinylcyclohexene diepoxide
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<pre>Chapter 4
        Mutagenicity and genotoxicity
4.1     In vitro assays
        4-Vinylcyclohexene diepoxide was mutagenic in the conventional mutagenicity
        assay using various strains of Salmonella typhimurium, in the presence and
        absence of an exogenous metabolic system.2 It, furthermore, induced mutations:
        in Saccharomyces cerevisiae (gene conversion, mitotic cross-over, and reverse
        mutations); at the hprt locus of Chinese hamster V79 cells; and, at the tk locus of
        mouse lymphoma L5178 cells, all in the absence of an exogenous metabolic sys-
        tem.2
            4-Epoxyethylcyclohexene-1,2-diol, a metabolite of 4-vinylcyclohexene diep-
        oxide, did not induce reverse mutations in Salmonella typhimurium TA100, nor
        did it cause gene mutations at the hprt locus of Chinese hamster V79 cells.2
        The agent also caused clastogenic effects in Chinese hamster ovary cells (sister
        chromatid exchanges, and chromosomal aberrations).2 Furthermore, it did
        increase the frequency of micronuclei in plant systems (Allium cepa, Vicia faba),
        but not in Chinese hamster V79 lung cells.2 Tests on micronucleus formation
        were performed without an exogenous metabolic system. Finally, the metabolite
        4-epoxyethylcyclohexene-1,2-diol increased the frequency of micronuclei in
        Chinese hamster V79 lung cells.2
        Mutagenicity and genotoxicity                                                       21
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<pre>4.2 In vivo assays
    Mabon et al. (1996) and Randerath et al. (1996), both of the same research
    group, showed that 4-vinylcyclohexene diepoxide is able to produce DNA
    adducts in vivo (female ICR mice; topical application; 17-225 μmol/ mouse;
    once a day for three days).7,8 The adduct levels were, however, far below the lev-
    els generally found for highly potent carcinogens at comparable doses, such as
    benzo[a]pyrene. No human or other animal data were available on the genotoxic-
    ity of 4-vinylcyclohexene diepoxide using in vivo bioassays.
4.3 Additional information and carcinogenic mechanism
    4-Vinylcyclohexene diepoxide is a potent electrophilic agent with alkylating
    properties.7,8 Regarding this property, Mabon et al. (1996) and Randerath et al.
    (1996) not only showed induction of DNA-adducts in mice, but also in isolated
    calf thymus DNA. Although the adduct levels were far below the levels generally
    found for highly potent carcinogens at comparable doses, such as
    benzo[a]pyrene, these results provide further evidence for a direct-acting carci-
    nogenic mechanism.
         Furthermore, 4-vinylcyclohexene diepoxide is a metabolite of 4-vinylcyclo-
    hexene, which exhibits selective toxicity in primordial and primary ovarian folli-
    cles and ovarian carcinogenicity in mice, but not in rats.9 Various animal studies
    showed that the diepoxide is also able to induce ovarian toxicity. Based on struc-
    ture-activity studies it is even suggested that the diepoxide metabolite is the ulti-
    mate ovotoxic compound, being more reactive than 4-vinylcyclohexene itself.10-12
         Another subject is the difference in susceptibility of 4-vinylcyclohexene
    diepoxide of ovarian carcinogenicity between mice and rats. Hoyer and Sipes
    (1996) reported that it has been shown that mice had reduced capacity to convert
    the diepoxide to its inactive tetrol derivate, as compared to rats.13 Thus, mice
    appear to be deficient in detoxifying the diepoxide, resulting in a greater suscep-
    tibility in ovarian toxicity than rats.
         The carcinogenic mechanism through which 4-vinylcyclohexene diepoxide
    exerts its effect on ovarian follicles is not completely understood, although stud-
    ies point to disruption in hormonal feedback due to destruction of primary
    oocytes.13 This would suggest a role as a tumour promotor. At least, the types of
    morphological lesions observed in destroyed follicles are consistent with (accel-
    erated) programmed cell death (apoptosis) rather than cytotoxicity or necrosis.12-14
22  4-Vinylcyclohexene diepoxide
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<pre>Chapter 5
        Classification
5.1     Evaluation of data on carcinogenicity and genotoxicity
        No data on the genotoxicity and carcinogenicity of 4-vinylcyclohexene diep-
        oxide in humans were available, nor were there any carcinogenicity data avail-
        able on inhalation exposure in animals. However, after chronic dermal
        application the agent did induce benign and malignant skin tumours in male and
        female rats and mice. It furthermore induced ovarian and lung tumours in female
        mice. Based on these findings, the committee is of the opinion that there is suffi-
        cient evidence for carcinogenicity in animals.
             4-Vinylcyclohexene diepoxide is in fact an electrophilic compound that was
        shown to be mutagenic in vitro in various test systems, and clastogenic in mam-
        malian cells. It, furthermore, increased the level of DNA adducts in vitro and in
        vivo. Based on these data, the committee considers the diepoxide as a genotoxic
        compound that acts by a stochastic mechanism. Regarding ovarian carcinogenic-
        ity, it should be taken into account that 4-vinylcyclohexene diepoxide might
        exert its effect also by acting as a promotor.
             The committee did not find indications that the observations in animals, and
        the proposed carcinogenic mechanism would not occur in humans.
        Classification                                                                      23
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<pre>5.2 Recommendation for classification
    The committee concludes that 4-vinylcyclohexene diepoxide should be consid-
    ered as carcinogenic to humans. This recommendation is comparable to the EU
    classification in category 2. The committee is furthermore of the opinion that 4-
    vinylcyclohexene diepoxide should be considered as a genotoxic agent that acts
    by a stochastic mechanism.
24  4-Vinylcyclohexene diepoxide
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<pre>  References
1 ACGIH. 4-Vinyl-1-cyclohexene diepoxide. ACGIH. Documentation of the threshold limit values and
  biological exposure indices, 11th report on carcinogens, pp 1708-1710; 2002.
2 International Agency for Research on Cancer. 4-vinylcyclohexene diepoxide. IARC Monographs on
  evaluating carcinogenic risk of chemicals in humans, Lyon, France, Volume 60, pp 361-372; 1994.
3 National Toxicology program. Toxicology and Carcinogenesis Studies of 4-Vinyl-1-cyclohexene
  Diepoxide (CAS No. 106-87-6) in F344/N Rats and B6C3F1 Mice (Dermal Studies). National
  Toxicology program, National Institute of Health, Research Triangle Park, NC, Technical report
  series no. 362; 1989.
4 Chhabra RS, Huff J, Haseman J, Jokinen MP, Hetjmancik M. Dermal toxicity and carcinogenicity of
  4-vinyl-1-cyclohexene diepoxide in Fischer rats and B6C3F1 mice. Fundam Appl Toxicol 1990;
  14(4): 752-763.
5 Tennant RW, Spalding J, French JE. Evaluation of transgenic mouse bioassays for identifying
  carcinogens and noncarcinogens. Mutat Res 1996; 365(1-3): 119-127.
6 Yamamoto S, Urano K, Koizumi H, Wakana S, Hioki K, Mitsumori K e.a. Validation of transgenic
  mice carrying the human prototype c-Ha-ras gene as a bioassay model for rapid carcinogenicity
  testing. Environ Health Perspect 1998; 106 Suppl 1: 57-69.
7 Mabon N, Randerath K. 32P-postlabeling of 1,3-butadiene and 4-vinyl-1-cyclohexene metabolite-
  DNA adducts: in vitro and in vivo applications. Toxicology 1996; 113(1-3): 341-344.
8 Randerath K, Mabon N. In vitro and in vivo (32)P-postlabeling analysis of 4-vinyl-1-cyclohexene
  (butadiene dimer) diepoxide-DNA adducts. Cancer Lett 1996; 101(1): 67-72.
9 Health Council of the Netherlands. 4-Vinylcyclohexene; Evaluation of the carcinogenicity and
  genotoxicity. The Hague: Health Council of the Netherlands; publication no. 2008/04OSH; 2008.
  References                                                                                      25
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<pre>10 Doerr JK, Hooser SB, Smith BJ, Sipes IG. Ovarian toxicity of 4-vinylcyclohexene and related olefins
   in B6C3F1 mice: role of diepoxides. Chem Res Toxicol 1995; 8(7): 963-969.
11 Doerr JK, Sipes IG. Ovarian toxicity and metabolism of 4-vinylcyclohexene and analogues in
   B6C3F1 mice: structure-activity study of 4-vinylcyclohexene and analogues. Adv Exp Med Biol
   1996; 387: 377-384.
12 Hoyer PB, Sipes IG. Assessment of follicle destruction in chemical-induced ovarian toxicity. Annu
   Rev Pharmacol Toxicol 1996; 36: 307-331.
13 Hoyer PB, Devine PJ, Hu X, Thompson KE, Sipes IG. Ovarian toxicity of 4-vinylcyclohexene
   diepoxide: a mechanistic model. Toxicol Pathol 2001; 29(1): 91-99.
14 Hu X, Christian PJ, Thompson KE, Sipes IG, Hoyer PB. Apoptosis induced in rats by 4-
   vinylcyclohexene diepoxide is associated with activation of the caspase cascades. Biol Reprod 2001;
   65(1): 87-93.
26 4-Vinylcyclohexene diepoxide
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<pre>A Request for advice
B The committee
C Comments on the public review draft
D IARC Monograph
E Carcinogenic classification of substances by the committee
F Guideline 93/21/EEG of the European Union
  Annexes
                                                             27
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<pre>Annex A
      Request for advice
      In a letter dated October 11, 1993, ref DGA/G/TOS/93/07732A, to, the State
      Secretary of Welfare, Health and Cultural Affairs, the Minister of Social Affairs
      and Employment wrote:
      Some time ago a policy proposal has been formulated, as part of the simplification of the governmen-
      tal advisory structure, to improve the integration of the development of recommendations for health
      based occupation standards and the development of comparable standards for the general population.
      A consequence of this policy proposal is the initiative to transfer the activities of the Dutch Expert
      Committee on Occupational Standards (DECOS) to the Health Council. DECOS has been established
      by ministerial decree of 2 June 1976. Its primary task is to recommend health based occupational
      exposure limits as the first step in the process of establishing Maximal Accepted Concentrations
      (MAC-values) for substances at the work place.
      In an addendum, the Minister detailed his request to the Health Council as fol-
      lows:
      The Health Council should advice the Minister of Social Affairs and Employment on the hygienic
      aspects of his policy to protect workers against exposure to chemicals. Primarily, the Council should
      report on health based recommended exposure limits as a basis for (regulatory) exposure limits for air
      quality at the work place. This implies:
      •    A scientific evaluation of all relevant data on the health effects of exposure to substances using a
           criteria-document that will be made available to the Health Council as part of a specific request
      Request for advice                                                                                        29
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<pre>       for advice. If possible this evaluation should lead to a health based recommended exposure limit,
       or, in the case of genotoxic carcinogens, a ‘exposure versus tumour incidence range’ and a calcu-
       lated concentration in air corresponding with reference tumour incidences of 10-4 and 10-6 per
       year.
   •   The evaluation of documents review the basis of occupational exposure limits that have been
       recently established in other countries.
   •   Recommending classifications for substances as part of the occupational hygiene policy of the
       government. In any case this regards the list of carcinogenic substances, for which the classifica-
       tion criteria of the Directive of the European Communities of 27 June 1967 (67/548/EEG) are
       used.
   •   Reporting on other subjects that will be specified at a later date.
   In his letter of 14 December 1993, ref U 6102/WP/MK/459, to the Minister of
   Social Affairs and Employment the President of the Health Council agreed to
   establish DECOS as a Committee of the Health Council.
30 4-Vinylcyclohexene diepoxide
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<pre>Annex B
      The committee
      •   G..J. Mulder, chairman
          emeritus professor of toxicology, Leiden University, Leiden
      •   P.J. Boogaard
          toxicologist, SHELL International BV, The Hague
      •   Ms. M.J.M. Nivard
          molecular biologist and genetic toxicologist, Leiden University Medical Cen-
          ter, Leiden
      •   G.M.H. Swaen
          epidemiologist, Dow Chemicals NV, Terneuzen
      •   R.A. Woutersen
          toxicologic pathologist, TNO Quality of Life, Zeist
      •   A.A. van Zeeland
          professor of molecular radiation dosimetry and radiation mutagenesis, Uni-
          versity Medical Center, Leiden
      •   E.J.J. van Zoelen
          professor of cell biology, Radboud University Nijmegen, Nijmegen
      •   J.M. Rijnkels, scientific secretary
          Health Council of the Netherlands, The Hague
      The committee consulted an additional expert, Prof. dr. G. Mohn, working at
      Department of Radiation Genetics and Chemical Mutagenesis of the University
      of Leiden, with respect to the genotoxic data.
      The committee                                                                    31
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<pre>   The Health Council and interests
   Members of Health Council Committees are appointed in a personal capacity
   because of their special expertise in the matters to be addressed. Nonetheless, it
   is precisely because of this expertise that they may also have interests. This in
   itself does not necessarily present an obstacle for membership of a Health Coun-
   cil Committee. Transparency regarding possible conflicts of interest is nonethe-
   less important, both for the President and members of a Committee and for the
   President of the Health Council. On being invited to join a Committee, members
   are asked to submit a form detailing the functions they hold and any other mate-
   rial and immaterial interests which could be relevant for the Committee’s work.
   It is the responsibility of the President of the Health Council to assess whether
   the interests indicated constitute grounds for non-appointment. An advisorship
   will then sometimes make it possible to exploit the expertise of the specialist
   involved. During the establishment meeting the declarations issued are dis-
   cussed, so that all members of the Committee are aware of each other’s possible
   interests.
32 4-Vinylcyclohexene diepoxide
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<pre>Annex C
      Comments on the public review draft
      A draft of the present report was released in 2007 for public review. The follow-
      ing organisations and persons have commented on the draft document:
      • E. González-Fernández, Ministerio de Trabajo y Asuntos Sociales, Spain;
      • R.D. Zumwalde, National Institute for Occupational Safety and Health, the
          USA.
      Comments on the public review draft                                               33
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<pre>Annex D
      IARC Monograph
      Vol.: 60 (1994) (p. 361)2
      CAS No.: 106-87-6
      Chem. Abstr. Name: 3-Oxiranyl-7-oxabicyclo[4.1.0]heptane
      Summary of Data Reported and Evaluation
      Exposure data
      4-Vinylcyclohexene diepoxide is produced by epoxidation of 4-vinylcyclohex-
      ene with peroxyacetic acid. It is used as a reactive diluent for other diepoxides
      and for epoxy resins. No data are available on levels of occupational exposure to
      4-vinylcyclohexene diepoxide.
      Human carcinogenicity data
      No data were available to the Working Group.
      Animal carcinogenicity data
      4-Vinylcyclohexene diepoxide was tested for carcinogenicity by skin application
      in three studies in mice and in one study in rats. Skin application of 4-vinylcyclo-
      hexene diepoxide produced benign and malignant skin tumours in all studies in
      IARC Monograph                                                                       35
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<pre>   mice and in the study in rats. In one study in mice, it also increased the inci-
   dences of ovarian and lung tumours in females.
   Other relevant data
   4-Vinylcyclohexene diepoxide can be absorbed through the skin of rodents.
   Higher concentrations tend to be found in the ovary rather than in other organs,
   and virtually all elimination occurs via the urine. Its metabolism involves hydra-
   tion to a mixture of glycols and conjugation with glutathione. 4-Vinylcyclohex-
   ene diepoxide is locally toxic and, when given orally, causes ovarian
   degeneration in both mice and rats and testicular degeneration in mice, as well as
   lesser effects in other organs. No data were available on the genetic and related
   effects of 4-vinylcyclohexene diepoxide in humans. 4-Vinylcyclohexene diep-
   oxide induced gene mutation, sister chromatid exchange and chromosomal aber-
   rations but not micronuclei in mammalian cells in vitro. It was mutagenic in
   bacteria and caused gene conversion and mitotic crossing-over in Saccharomyces
   cerevisiae. A metabolite of 4-vinylcyclohexene diepoxide, 4-epoxyethylcyclo-
   hexane-1,2-diol, was not mutagenic to Salmonella typhimurium.
   Evaluation
   There is inadequate evidence in humans for the carcinogenicity of 4-vinylcylco-
   hexene diepoxide. There is sufficient evidence in experimental animals for the
   carcinogenicity of 4-vinyl-cyclohexene diepoxide.
   Overall evaluation
   4-Vinylcyclohexene diepoxide is possibly carcinogenic to humans (Group 2B).
   Previous evaluation: Suppl. 7 (1987) (p. 63)
36 4-Vinylcyclohexene diepoxide
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<pre>Annex         E
              Carcinogenic classification of
              substances by the committee
The committee expresses its conclusions in the form of standard phrases:
Judgment of the committee                                                                       Comparable with EU class
This compound is known to be carcinogenic to humans                                             1
•   It is stochastic or non-stochastic genotoxic
•   It is non-genotoxic
•   Its potential genotoxicity has been insufficiently investigated. Therefore, it is unclear
    whether it is genotoxic
This compound should be regarded as carcinogenic to humans                                      2
•   It is stochastic or non-stochastic genotoxic
•   It is non-genotoxic
•   Its potential genotoxicity has been insufficiently investigated. Therefore, it is unclear
    whether it is genotoxic
This compound is a suspected human carcinogen.                                                  3
•   This compound has been extensively investigated. Although there is insufficient evidence    (A)
    for a carcinogenic effect to warrant a classification as ‘known to be carcinogenic to
    humans’ or as ‘should be regarded as carcinogenic to humans’, they indicate that there is
    cause for concern.
•   This compound has been insufficiently investigated. While the available data do not war-    (B)
    rant a classification as ‘known to be carcinogenic to humans’ or as ‘should be regarded as
    carcinogenic to humans’, they indicate that there is a cause for concern.
This compound cannot be classified                                                              not classifiable
•   There is a lack of carcinogenicity and genotoxicity data.
•   Its carcinogenicity is extensively investigated. The data indicate sufficient evidence sug-
    gesting lack of carcinogenicity.
              Carcinogenic classification of substances by the committee                                             37
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<pre>Annex F
      Guideline 93/21/EEG of the European
      Union
      4.2            Criteria for classification, indication of danger, choice of risk phrases
      4.2.1          Carcinogenic substances
      For the purpose of classification and labelling, and having regard to the current state of knowledge,
      such substances are divided into three categories:
      Category 1:
      Substances known to be carcinogenic to man.
      There is sufficient evidence to establish a causal association between human exposure to a substance
      and the development of cancer.
      Category 2:
      Substances which should be regarded as if they are carcinogenic to man.
      There is sufficient evidence to provide a strong presumption that human exposure to a substance may
      result in the development of cancer, generally on the basis of:
      •    appropriate long-term animal studies
      •    other relevant information.
      Guideline 93/21/EEG of the European Union                                                             39
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<pre>   Category 3:
   Substances which cause concern for man owing to possible carcinogenic effects but in
   respect of which the available information is not adequate for making a satisfactory assess-
   ment.
   There is some evidence from appropriate animal studies, but this is insufficient to place the substance
   in Category 2.
   4.2.1.1       The following symbols and specific risk phrases apply:
   Category 1 and 2:
   T; R45 May cause cancer
   However for substances and preparations which present a carcinogenic risk only when inhaled, for
   example, as dust, vapour or fumes, (other routes of exposure e.g. by swallowing or in contact with
   skin do not present any carcinogenic risk), the following symbol and specific risk phrase should be
   used:
   T; R49 May cause cancer by inhalation
   Category 3:
   Xn; R40 Possible risk of irreversible effects
   4.2.1.2       Comments regarding the categorisation of carcinogenic substances
   The placing of a substance into Category 1 is done on the basis of epidemiological data; placing into
   Categories 2 and 3 is based primarily on animal experiments.
   For classification as a Category 2 carcinogen either positive results in two animal species should be
   available or clear positive evidence in one species; together with supporting evidence such as geno-
   toxicity data, metabolic or biochemical studies, induction of benign tumours, structural relationship
   with other known carcinogens, or data from epidemiological studies suggesting an association.
40 4-Vinylcyclohexene diepoxide
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<pre>Category 3 actually comprises 2 sub-categories:
a    substances which are well investigated but for which the evidence of a tumour-inducing effect is
     insufficient for classification in Category 2. Additional experiments would not be expected to
     yield further relevant information with respect to classification.
b    substances which are insufficiently investigated. The available data are inadequate, but they
     raise concern for man. This classification is provisional; further experiments are necessary
     before a final decision can be made.
For a distinction between Categories 2 and 3 the arguments listed below are relevant which reduce
the significance of experimental tumour induction in view of possible human exposure. These argu-
ments, especially in combination, would lead in most cases to classification in Category 3, even
though tumours have been induced in animals:
•    carcinogenic effects only at very high levels exceeding the 'maximal tolerated dose'. The maxi-
     mal tolerated dose is characterized by toxic effects which, although not yet reducing lifespan, go
     along with physical changes such as about 10% retardation in weight gain;
•    appearance of tumours, especially at high dose levels, only in particular organs of certain species
     is known to be susceptible to a high spontaneous tumour formation;
•    appearance of tumours, only at the site of application, in very sensitive test systems (e.g. i.p. or
     s.c. application of certain locally active compounds);
•    if the particular target is not relevant to man;
•    lack of genotoxicity in short-term tests in vivo and in vitro;
•    existence of a secondary mechanism of action with the implication of a practical threshold above
     a certain dose level (e.g. hormonal effects on target organs or on mechanisms of physiological
     regulation, chronic stimulation of cell proliferation;
•    existence of a species - specific mechanism of tumour formation (e.g. by specific metabolic
     pathways) irrelevant for man.
For a distinction between Category 3 and no classification arguments are relevant which exclude a
concern for man:
•    a substance should not be classified in any of the categories if the mechanism of experimental
     tumour formation is clearly identified, with good evidence that this process cannot be extrapo-
     lated to man;
•    if the only available tumour data are liver tumours in certain sensitive strains of mice, without
     any other supplementary evidence, the substance may not be classified in any of the categories;
•    particular attention should be paid to cases where the only available tumour data are the occur-
     rence of neoplasms at sites and in strains where they are well known to occur spontaneously with
     a high incidence.
Guideline 93/21/EEG of the European Union                                                                 41
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<br><br>