<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>      Oxalonitrile
      (CAS No: 460-19-5)
      Health-based Reassessment of Administrative
      Occupational Exposure Limits
      Committee on Updating of Occupational Exposure Limits,
      a committee of the Health Council of the Netherlands
      No. 2000/15OSH/063, The Hague, 3 March 2003
063-1
</pre>

====================================================================== Einde pagina 1 =================================================================

<br><br>====================================================================== Pagina 2 ======================================================================

<pre>      Preferred citation:
      Health Council of the Netherlands: Committee on Updating of Occupational
      Exposure Limits. Oxalonitrile; Health-based Reassessment of Administrative
      Occupational Exposure Limits. The Hague: Health Council of the Netherlands,
      2003; 2000/15OSH/063.
      all rights reserved
063-2
</pre>

====================================================================== Einde pagina 2 =================================================================

<br><br>====================================================================== Pagina 3 ======================================================================

<pre>1     Introduction
      The present document contains the assessment of the health hazard of
      oxalonitrile by the Committee on Updating of Occupational Exposure Limits, a
      committee of the Health Council of the Netherlands. The first draft of this
      document was prepared by M Busschers, M.Sc., and H Stouten, M.Sc. (TNO
      Nutrition and Food Research, Zeist, the Netherlands).
          The evaluation of the toxicity of oxalonitrile has been based on the review
      by the American Conference of Governmental Industrial Hygienists (ACG98).
      Where relevant, the original publications were reviewed and evaluated as will
      be indicated in the text. In addition, literature was retrieved from the on-line
      databases Medline, Toxline, Chemical Abstracts, and NIOSHTIC covering the
      period 1966 to May 1999, 1965 to February 1999, 1967 to May 1999, and 1973
      to April 1998, respectively, and using the following key words: dicyan,
      ethanedinitrile, carbon nitride, dicyanogen, nitriloacetonitrile, oxalic acid
      dinitrile, oxalonitrile, oxalyl cyanide, and 460-19-5. HSDB and RTECS,
      databases available from CD-ROM, were consulted as well (NIO99, NLM99).
      The final literature search was carried out in April 1999.
          In September 2001, the President of the Health Council released a draft of
      the document for public review. The committee received no comments.
          An additional search in May 2002 did not result in information changing the
      committee's conclusions.
2     Identity
       name                             :   oxalonitrile
       synonyms                         :   cyanogen*; carbon nitride; dicyan; dicyanogen;
                                            ethanedinitrile; nitriloacetonitrile; oxalic acid dinitrile;
                                            oxalyl cyanide; prussite
       molecular formula                :   C2N2
       molecular structure              :   N≡C-C≡N
       CAS number                       :   460-19-5
       a
            name used in this document
      Data from ACG98, Ric93.
063-3 Oxalonitrile
</pre>

====================================================================== Einde pagina 3 =================================================================

<br><br>====================================================================== Pagina 4 ======================================================================

<pre>3     Physical and chemical properties
       molecular weight                :    52,04
       boiling point                   :    -21.2oC
       melting point                   :    -27.9oC
       flash point                     :    -
       vapour pressure                 :    at 20oC: 538 kPa
       solubility in water             :    soluble
       log Poctanol/water              :    0.07 (both experimental and estimated)
       conversion factors              :    1 ppm = 2.2 mg/m3
       (20oC, 101.3 kPa)                    1 mg/m3 = 0.46 ppm
      Data from ACG98, Ano81, Har94, NLM99, http://esc.syrres.com.
      Cyanogen is a colourless gas with a pungent, penetrating, almond-like odour.
      The odour threshold is reported as being about 500 mg/m3 (230 ppm) (Rut86),
      while another study reports that humans did not detect any odour up to 550
      mg/m3 (250 ppm, the highest concentration tested) (McN60).
4     Uses
      Cyanogen is primarily used in organic synthesis. It is, however, also used as a
      fuel gas for welding and cutting heat-resistant metals, as a rocket and missile
      propellant (with ozone or fluorine), and as a fumigant (ACG98). At one time, it
      was used in poison gas warfare (Ano81).
5     Biotransformation and kinetics
      In cells, cyanogen combines with enzymes involved in the cellular oxygen
      transport and arrests oxidation in those cells (Lew84). The committee did not
      find further information on the biotransformation or kinetics of cyanogen.
           Cyanogen hydrolyses to yield one molecule of hydrogen cyanide (HCN) and
      one of cyanate. The metabolism of cyanide has been reviewed in a criteria
      document on HCN, NaCN, and KCN by another committee of the Health
      Council, viz., the Dutch Expert Committee on Occupational Standards
      (DECOS). In summary, cyanide is distributed to many organs and the blood. At
063-4 Health-based Recommended Occupational Exposure Limits
</pre>

====================================================================== Einde pagina 4 =================================================================

<br><br>====================================================================== Pagina 5 ======================================================================

<pre>      lethal or nearly lethal doses of these cyanides, relatively high concentrations
      were found in the liver, lungs, kidneys, brain, and blood. Various
      biotransformation pathways have been identified for cyanide. The most
      important way is the formation of thiocyanate by the acceptance of a
      sulphane-sulphur of thiosulphate or other sulphane-sulphur-containing
      compounds (transsulphurisation), the key enzyme being rhodanese. The
      rate-limiting factor of this pathway is the lack of sulphane-sulphur sources in
      the body. Cyanide is largely eliminated from the body via the urinary excretion
      of thiocyanates in the case of high exposure levels. Other minor elimination
      routes include the exhalation of carbon dioxide and traces of hydrogen cyanide.
      The relative importance of various biotransformation and elimination routes is
      unknown for lower, clearly sublethal exposure levels (Hea02).
6     Effects and mechanism of action
      Human data
      Human volunteers experienced nasal and eye irritation when they were exposed
      to 35 mg/m3 (16 ppm), for 6-8 minutes. A concentration of 18 mg/m3 (8 ppm)
      for 6 minutes did not result in any irritation. Human subjects were unable to
      detect any odour from concentrations of cyanogen as high as 550 mg/m3 (250
      ppm) (McN60).
           Generally, cyanogen possesses the same general type of toxicity and mode
      of action as hydrogen cyanide although cyanogen appears to be more irritating
      (Har94).
      Animal data
      Irritation and sensitisation
      Dermal exposure of rabbits to cyanogen gas in an acute toxicity study indicates
      that cyanogen is not a skin irritant. Irritation of the eyes and upper respiratory
      tract was reported in an acute inhalation study, but a detailed description of the
      irritating effects on the different tissues was not available (McN60).
           The committee did not find any data on the potential sensitising properties
      of cyanogen.
063-5 Oxalonitrile
</pre>

====================================================================== Einde pagina 5 =================================================================

<br><br>====================================================================== Pagina 6 ======================================================================

<pre>            Acute toxicity
            In an acute inhalation study, male rats (n=6/group) were exposed to cyanogen
            ranging from 540-8540 mg/m3 (250-4000 ppm), for 7.5-120 minutes. Symptoms
            included eye and upper respiratory tract irritation, huddling together with
            inactivity, slow gasping, fluid from nose and mouth, poorly coordinated
            movements, bright pink colouration of the skin, laboured breathing, tremors,
            and, eventually, death. No macroscopic abnormalities were found. Mortality
            was dependent on dose and length of exposure: exposure to 850 mg/m3 (400
            ppm) for 45 minutes caused no mortality, whereas none of the animals survived
            a 1-hour exposure to the same concentration. The longest exposure (2 hours) to
            540 mg/m3 (250 ppm) resulted in the death of 2/6 rats during exposure and a
            further 2 rats died within 7 days after exposure. The 1-hour LC50 for cyanogen
            was 750 mg/m3 (350 ppm) (McN60).
            Some other toxicity data concerning acute exposure by inhalation are presented
            in Table 1.
Table 1 Summary of effects of cyanogen following single exposure by inhalation (data from Flu31).
speciesa     concentrationb                         duration (min)         response
             mg/m3               ppm
mouse        500                 235                15                     tolerated
             5 500               2 600              12                     fatal
             31,5                15                 <1                     fatal
rabbit       210                 100                240                    practically no effects
             420                 200                240                    slight symptoms
             630                 300                210                    severe symptoms, delayed death
             840                 400                105                    fatal
cat          100                 50                 240                    severe symptoms, recovery
             160                 75                 240                    severe symptoms, fatal after 2 days
             210                 100                120-180                fatal
             420                 200                30                     fatal
             4 260               2 000              13                     fatal
a
      Sex and number not reported.
b
      Conversion by Flury and Zernik.
            Dermal exposure of rabbits to 22,000 mg/m3 (10,000 ppm), for 8 hours, did not
            result in any clinical observations or macroscopic effects (McN60).
063-6       Health-based Recommended Occupational Exposure Limits
</pre>

====================================================================== Einde pagina 6 =================================================================

<br><br>====================================================================== Pagina 7 ======================================================================

<pre>      Repeated-dose toxicity
      Male rhesus monkeys (n=5/group) and male rats (n=30/group, including 4
      interim kills per exposure level) were exposed to 25 mg/m3 (11 ppm) or 56
      mg/m3 (25 ppm) cyanogen gas for 6 months (6 hours/day, 5 days/week). Body
      weights of rats exposed to 56 mg/m3 for 6 months (n=6) were statistically
      significantly decreased; the mean body weights after 6 months of exposure were
      543, 589, and 470 g for the control, the low- exposure group, and the
      high-exposure group, respectively. The total lung moisture content was lower in
      cyanogen-exposed monkeys than in control monkeys. The effect was not noted
      in rats and the biological relevance of this finding was considered unclear, also
      since no histological changes were observed. Moreover, no lung function
      parameters were studied, actual data on the (decrease in) moisture content were
      not reported and, hence, no information on a possible dose-response
      relationship was available. Behavioural testing was conducted in monkeys only.
      Although the response rate of all monkeys was reported to be slightly increased
      in the exposure period compared to baseline (pre-exposure) data, it was noted
      that the baseline response of the high-dose group was a factor 2 lower than that
      of the other groups. Furthermore, it should be noted that this effect was noted
      against a background of disturbingly low overall rates and high variability. No
      further abnormalities were noted in haematology or clinical biochemistry
      parameters, electrocardiograms (monkeys only), and macro- and microscopic
      examinations of heart, liver, kidney, cerebellum, cerebrum, lungs, thyroid,
      spleen, and bone marrow (upper respiratory tract was not examined). According
      to the authors, the findings suggested that inhaled cyanogen gas, under the
      conditions of this study, did not induce any organ specific or systemic toxicity
      but that 56 mg/m3 (25 ppm) was likely to produce minor, untoward changes
      (Lew84). The committee considers the lung effects observed in the monkeys as
      non-adverse and 25 mg/m3 (11 ppm) to be the NOAEL in this study. It should
      be kept in mind that the upper respiratory tract was not investigated in this
      study.
      The committee did not find data on the potential genotoxicity, carcinogenicity,
      or reproduction toxicity of cyanogen.
063-7 Oxalonitrile
</pre>

====================================================================== Einde pagina 7 =================================================================

<br><br>====================================================================== Pagina 8 ======================================================================

<pre>      Systemic effects due to cyanide exposure
      Since cyanogen hydrolyses to yield cyanate and cyanide systemic effects may
      arise which are due to the cyanide formed. Therefore, the findings as presented
      in the aforementioned criteria document on HCN, NaCN, and KCN will be
      summarised here. In humans, exposure to lethal or nearly lethal doses leads to a
      series of respiratory, cardiovascular, and neurological symptoms. Death is
      preceded by coma, and is caused by respiratory failure or cardiac arrest. Acute
      toxicity is characterised by a rather steep dose-response/effect relationship:
      exposure to 20 mg HCN/m3 for several hours may lead to slight effects only,
      while exposure to 120 mg HCN/m3 may be fatal. Survival of serious acute
      poisoning may be followed by severe neurotoxicological sequelae. Some case
      studies suggested that human cyanide toxicity is not restricted to acute effects
      and their sequelae, but that effects may gradually develop upon repeated
      exposure, in particular neurotoxicity and goitre. However, it was not possible to
      link these effects to exposure levels. In one epidemiological study in which
      exposure levels were 4.2 to 12.4 ppm (4.7-13.9 mg CN-/m3), higher incidences
      of a number of symptoms (headache; weakness; changes in taste and smell;
      giddiness; throat irritation; vomiting, dyspnoea; lachrymation; precordial pain;
      salivation; disturbances of accommodation; psychosis) were reported in
      occupationally exposed workers when compared to not-exposed controls, as
      well as enlarged thyroids, pointing to goitre, in most of the exposed workers. In
      experimental animals, similar respiratory, cardiovascular, and neurological
      effects are observed following single exposures. Depending on species,
      compound, and exposure duration, the respiratory LC50 ranged between 134 and
      410 ppm (149-455 mg/m3). Repeated exposures (12 exposures of ½ h, 1
      exposure per 8 days, or 14 or 19 exposures of ½ h, 1 exposure per 2 days) to 50
      mg HCN/m3 resulted in severe histological brain lesions in dogs; no histological
      effects were observed in hearts, lungs, and adjacent arteries of rabbits
      continuously exposed to 0.5 mg HCN/m3, for 4 weeks. A wide variety of
      effects, among others on behaviour, the CNS, and the male reproduction, were
      reported from short-term oral experiments in experimental animals at daily
      doses of 0.4 mg KCN, 0.5 mg NaCN, and 3.5 mg NaCN/kg bw. No effects were
      seen in rats orally exposed to about 3.5 mg HCN/kg bw/day, for 2 years. No
      indications for a carcinogenic or genotoxic potential were found. However,
      because of flaws in design of the long-term studies and the limited number of
      genotoxicity endpoints examined, no definitive conclusions could be drawn.
      Cyanides were embryotoxic and teratogenic at maternally toxic doses. Since
063-8 Health-based Recommended Occupational Exposure Limits
</pre>

====================================================================== Einde pagina 8 =================================================================

<br><br>====================================================================== Pagina 9 ======================================================================

<pre>      lower doses were not tested, a definitive conclusion concerning reproduction
      toxicity cannot be drawn either. Finally, DECOS concluded that the most
      important primary effect of cyanide is the inhibition of the enzyme cytochrome
      C oxidase in the respiratory chain, thus blocking the utilisation of oxygen and
      the production of ATP by oxidative phosphorylation. Cyanides can inhibit other
      metallo enzymes as well; however, the effects of this inhibition are assumed to
      be overshadowed by the effects of the inhibition of cytochrome C oxidase, at
      least at the high doses investigated (Hea02).
7     Existing guidelines
      The current administrative occupational exposure limit (MAC) for cyanogen in
      the Netherlands is 20 mg/m3 (10 ppm), 8-hour TWA.
           Existing occupational exposure limits for cyanogen in some European
      countries and in the USA are summarised in the annex.
           From its criteria document on HCN, NaCN, and KCN, DECOS recommends
      a health-based occupational exposure limit of 1 mg CN-/m3, 8-hour TWA, and a
      ceiling limit of 10 mg CN-/m3, for any combination of these 3 compounds
      (Hea02).
8     Assessment of health hazard
      Data on humans and rats indicate that cyanogen can cause nasal and/or eye
      irritation. In human volunteers, no irritation was observed during a 6-minute
      exposure to 18 mg/m3 (8 ppm) while eye and nasal irritation were experienced
      at 35 mg/m3 (16 ppm) (McN60).
           No data were found on the potential sensitising properties of cyanogen.
           An inverse correlation was noted between concentration and exposure-time
      in an acute inhalation study, in which rats were exposed to cyanogen
      concentrations ranging from 540-8540 mg/m3 (250-4000 ppm) for 7.5-120
      minutes. The symptoms included asphyxiation, lachrymation, poorly
      coordinated movements, pink colouration of the noticeable skin, and,
      eventually, death. A 2-hour exposure to 540 mg/m3 (250 ppm) caused the death
      of 4/6 rats. The 1-hour LC50 was 750 mg/m3 (350 ppm) (McN60).
           Other acute inhalation data indicate that cyanogen is toxic by inhalation to
      various species. Exposures to 210 mg/m3 (100 ppm), for 2-3 hours, and to 840
      mg/m3 (400 ppm), for less than 2 hours, were lethal to cats and rabbits,
      respectively (Har94).
063-9 Oxalonitrile
</pre>

====================================================================== Einde pagina 9 =================================================================

<br><br>====================================================================== Pagina 10 ======================================================================

<pre>            Acute dermal exposure of rabbits to 22,000 mg/m3 (10,000 ppm), for 8
       hours, did not result in any clinical observations or macroscopic effects
       (McN60).
            Repeated exposure of monkeys and rats to 25 mg/m3 (11 ppm) or 56 mg/m3
       (25 ppm) cyanogen gas, for 6 months, did not result in mortality or other severe
       effects. Effects noted were a decreased body weight of rats exposed to 56
       mg/m3 and a reduced moisture content of the lungs in both groups of
       cyanogen-treated monkeys (Lew84). However, potential upper respiratory tract
       irritation was not addressed in this study.
            No data were found on the potential genotoxicity, carcinogenicity, or
       reproduction toxicity of cyanogen.
            The committee takes the NOAEL of 25 mg/m3 found in the 6-month
       inhalation study in rats and monkeys as a starting point in deriving a
       health-based recommended occupational exposure limit (HBROEL). For the
       extrapolation to a HBROEL, an overall assessment factor of 9 is established.
       This factor covers the following aspects: the intra- and interspecies variation.
       Thus, applying this factor of 9 and the preferred value approach, a health-based
       occupational exposure limit of 2 mg/m3 is recommended for oxalonitrile. In
       view of the NOAEL and LOAEL for irritation of 18 and 35 mg/m3 (8 and 16
       ppm), respectively, found in human volunteers exposed for 6-8 minutes, the
       committee is of the opinion that this HBROEL will be sufficiently low to offer
       protection against irritation as well. Furthermore, since one molecule of
       cyanogen yields 2 CN- ions, the HBROEL of 2 mg/m3 is very well in line with
       the HBROEL for CN- of 1 mg/m3.
       The committee recommends a health-based occupational limit for oxalonitrile of
       2 mg/m3, as an 8-hour time-weighted average.
       References
ACG98  American Conference of Governmental Industrial Hygienists (ACGIH). Cyanogen. In: TLVs® and other
       occupational exposure values - 1998. [CD-ROM]. Cincinnati OH, USA: ACGIH, 1998.
ACG02a American Conference of Governmental Industrial Hygienists (ACGIH). Guide to occupational exposure values -
       2002. Cincinnati OH, USA: ACGIH®, Inc, 2002: 35.
ACG02b American Conference of Governmental Industrial Hygienists (ACGIH). 2002 TLVs® and BEIs®. Threshold Limit
       Values for chemical substances and fysical agents. Biological Exposure Indices. Cincinnati OH, USA: ACGIH®,
       Inc, 2002: 24.
063-10 Health-based Recommended Occupational Exposure Limits
</pre>

====================================================================== Einde pagina 10 =================================================================

<br><br>====================================================================== Pagina 11 ======================================================================

<pre>Ano81  Anonymous. Information profiles on potential occupational hazards, volume 1, single chemicals. Cyanogen.
       Syracuse NY, USA: Syracuse Research Corp, Cent Chem Hazard Assessment, 1981 (available from the National
       Technical Information Service, Springfield VA, USA; rep no PB81-147977).
Arb02  Arbejdstilsynet. Grænseværdier for stoffer og materialer. Copenhagen, Denmark: Arbejdstilsynet, 2002: 23
       (At-vejledning C.0.1).
DFG02  Deutsche Forschungsgemeinschaft (DFG): Commission for the Investigation of Health Hazards of Chemical
       Compounds in the Work Area. List of MAK and BAT values 2002. Maximum concentrations and biological
       tolerance values at the workplace. Weinheim, FRG: Wiley-VCH, 2002: 43 (rep no 38).
EC02   European Commission: Directorate General of Employment and Social Affairs. Occupational exposure limits
       (OELs). http://europe.eu.int/comm/employment_social/h&s/areas/oels_en.htm.
Flu31  Flury F, Zernik F. Schädliche Gase. Dämpfe, Nebel, Rauch- und Staubarten. Berlin: Julius Springer, 1931:
       409-10.
Har94  Hartung R. Cyanides and nitriles. In: Clayton GD, Clayton FE, eds. Toxicology. 4th ed. New York: John Wiley &
       Sons, 1994: 3130-2 (Patty's industrial hygiene and toxicology; Vol II, Pt D).
Hea02  Health Council of the Netherlands: Dutch Expert Committee on Occupational Standards. Hydrogen cyanide,
       sodium cyanide, and potassium cyanide; Health-based recommended occupational exposure limits. The Hague,
       the Netherlands: Health Council of the Netherlands, 2002; publ no 2002/15OSH.
HSE02  Health and Safety Executive (HSE). EH40/2002. Occupational Exposure Limits 2002. Sudbury (Suffolk),
       England: HSE Books, 2002: 23.
Lew84  Lewis TR, Anger WK, Te Vault RK. Toxicity evaluation of sub-chronic exposures to cyanogen in monkeys and
       rats. J Environ Pathol Toxicol Oncol 1984; 5: 151-63.
McN60  McNerney JM, Schrenk HH. The acute toxicity of cyanogen. Am Ind Hyg Assoc J 1960; 21: 121-4.
NIO99  US National Institute of Occupational Safety and Health (NIOSH). Cyanogen (C2N2). In: Registry of Toxic
       Effects of Chemical Substances (RTECS). [CD-ROM], issue July 1999. SilverPlatter International, 1999 (last
       update cyanogen file: July 1999).
NLM99  US National Library of Medicine (NLM). Cyanogen. In: Hazardous Substances Data Bank (HSDB). [CD-ROM],
       issue July 1999. SilverPlatter International, 1999 (last update cyanogen file: March 1999).
Ric93  Richardson ML, Gangolli S, eds. C461 Cyanogen. In: The dictionary of substances and their effects. Cambridge,
       UK: Royal Society of Chemistry, 1993: 719-20 (Vol 2).
Rut86  Ruth JH. Odor thresholds and irritation levels of several chemical substances: a review. Am Ind Hyg Assoc J
       1986; 47: 142-51.
063-11 Oxalonitrile
</pre>

====================================================================== Einde pagina 11 =================================================================

<br><br>====================================================================== Pagina 12 ======================================================================

<pre>Swe00  Swedish National Board of Occupational Safety and Health. Occupational exposure limit values and measures
       against air contaminants. Solna, Sweden: National Board of Occupational Safety and Health, 2000; Ordinance
       AFS 2000:3.
SZW02  Ministerie van Sociale Zaken en Werkgelegenheid (SZW). Nationale MAC-lijst 2002. The Hague, the
       Netherlands: Sdu, Servicecentrum Uitgevers, 2002: 37.
TRG00  TRGS 900. Grenzwerte in der Luft am Arbeitsplatz; Technische Regeln für Gefahrstoffe. BArbBl 2001; 2
.
063-12 Health-based Recommended Occupational Exposure Limits
</pre>

====================================================================== Einde pagina 12 =================================================================

<br><br>====================================================================== Pagina 13 ======================================================================

<pre>             Annex
Occupational exposure limits for cyanogen in various countries
country                        occupational                     time-weighted   type of        notea        referenceb
- organisation                 exposure limit                   average         exposure limit
                               ppm            mg/m3
the Netherlands
- Ministry of Social Affairs   10             20                8h              administrative              SZW02
and Employment
Germany
- AGS                          10             22                8h                             S            TRG00
                               40             88                15 min
- DFG MAK-Kommission           10             22                8h                                          DFG02
                               20             44                15 minc
Great Britain
- HSE                          10             22                8h              OES                         HSE02
Sweden                         -              -                                                             Swe00
Denmark                        10             20                8h                                          Arb02
USA
- ACGIH                        10             -                 8h              TLV                         ACG02b
- OSHA                         -              -                                                             ACG02a
- NIOSH                        10             20                10 h            REL                         ACG02a
European Union
- SCOEL                        -              -                                                             EC02
a
  S = skin notation, which means that skin absorption may contribute considerably to body burden; sens = substance can
cause sensitisation.
b
  Reference to the most recent official publication of occupational exposure limits.
c
  Maximum number per shift: 4, with a minimum interval between peaks of 1 hour.
063-13       Oxalonitrile
</pre>

====================================================================== Einde pagina 13 =================================================================

<br><br>====================================================================== Pagina 14 ======================================================================

<pre>063-14 Health-based Recommended Occupational Exposure Limits</pre>

====================================================================== Einde pagina 14 =================================================================

<br><br>