Addendum 1 to the Draft Assessment Report

Transcription

1 Addendum 1 to the Draft Assessment Report of 22 November 2000 Benzoic acid Volume 1, Level 2 Volume 3, B.2 Physical and chemical properties B.4 Proposals for the classification and labelling B.6 Toxicology and metabolism 18 June 2003 Rapporteur Member State: Germany

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3 - i - Addendum 1 to the draft assessment report of benzoic acid Contents 18 June 2003 Contents VOLUME Appendix III.3: Chapter 3 (Impact on human and animal health)...1 VOLUME B.2 Physical and chemical properties...4 B.2.2 Physical, chemical and technical properties of the plant protection products (Annex IIIA 2)...4 B.2.3 References relied on...5 B.4 Proposals for the classification and labelling...5 B.6. Toxicology and metabolism...5 B.6.2 Acute toxicity including irritancy and skin sensitization (Annex IIA 5.2)...5 B Acute inhalative toxicity studies with benzoic acid...5 B.6.3 Short-term toxicity (Annex IIA 5.3)...6 B Short term toxicity studies in rats...6 B Inhalative study, Rat...6 B.6.11 Acute toxicity including irritancy and skin sensitization of preparations (Annex IIIA 7.1)...8 B Skin sensitization (formulation)...8

4 -1 Addendum 1 to the draft assessment report of benzoic acid Contents 18 June 2003 VOLUME Appendix III.3: Chapter 3 (Impact on human and animal health) Introductory remark BA and SB are widely spread natural compounds, a constituent in many foodstuffs and used as preservative in food, cosmetics and pharmaceuticals. Any additional exposure of the general population from the intended uses can be excluded. Absorption, distribution, excretion and metabolism in mammals (Annex IIA, point 5.1) Rate and extent of absorption Rapid (peak plasma concentration within 1-2 hours), nearly complete (excretion up to 100%), human data Distribution Widely distributed Potential for accumulation No potential Rate and extent of excretion Depending on species (in man and rat % within 24 h) Metabolism in animals Completely metabolized in humans; conjugation with glycine to hippuric acid (up to 100%) and glucuronic acid to benzoylglucuronic acid (0-20%) Toxicologically significant compounds Parent material (animals, plants and environment) Acute toxicity (Annex IIA, point 5.2) Rat LD 50 oral BA: 1700 mg/kg bw SB: 2100 mg/kg bw Rabbit LD 50 dermal BA: > 5000 mg/kg bw Rat LC 50 inhalation BA: > 1.2 mg/l (6 h exposure; first exposure during the subacute inhalative study) Skin irritation BA: Not irritating SB: Not irritating Eye irritation BA: Severely irritating (R 41) SB: Not irritating Skin sensitization (test method used and BA: Not sensitizing (M & K) result)

5 -2 Addendum 1 to the draft assessment report of benzoic acid Contents 18 June 2003 Short term toxicity (Annex IIA, point 5.3) Target / critical effect Lowest relevant oral NOAEL / NOEL Lowest relevant dermal NOAEL / NOEL Lowest relevant inhalation NOAEL / NOEL Liver, kidney, brain Rat, all relevant studies: ca 500 mg/kg bw/d No data, not required 4 week, rat: no NOAEL established, LOEL: mg/l Genotoxicity (Annex IIA, point 5.4) No genotoxic potential Long term toxicity and carcinogenicity (Annex IIA, point 5.5) Target / critical effect No target identified Lowest relevant NOAEL / NOEL Rat, all relevant studies: ca 500 mg/kg bw/d Carcinogenicity No carcinogenic potential Reproductive toxicity (Annex IIA, point 5.6) Reproduction target / critical effect Lowest relevant reproductive NOAEL / NOEL Developmental target / critical effect Lowest relevant developmental NOAEL / NOEL No reproductive effect at highest dose level tested (combined chronic/reproduction study, 4 generations) Ca 750 mg/kg bw/d Abnormalities/malformations in eye, kidney and brain at severe maternaltoxic doses Rat: ca 500 mg/kg bw/d Neurotoxicity / Delayed neurotoxicity (Annex IIA, point 5.7) No data, not required Effect on brain only in one short-term study at one high dose (1967, without guideline) Other toxicological studies (Annex IIA, point 5.8) Glycine, ATP and coenzyme A can be reduced by BA and SB.

6 -3 Addendum 1 to the draft assessment report of benzoic acid Contents 18 June 2003 Medical data (Annex IIA, point 5.9) Tolerance for BA, SB varies in a wide range (ca 3 to 42 g at single administration) SB is therapeutically used, e.g. treatment of hyperammonemia to 0.15% of the general population react sensitively to pseudoallergic substances in food (non-immune immediate contact reactions, NIICRs) No sensitization potential of BA and benzoates in a maximization test developed for humans Summary (Annex IIA, point 5.10) Value Study Safety factor ADI 5 mg/kg bw Overall evaluation of shortterm 100 and long-term studies, rat AOEL systemic 5 mg/kg bw Overall evaluation of shortterm 100 and long-term studies, rat Drinking water limit Not allocated not necessary ARfD (acute reference dose) Not allocated not necessary Dermal absorption (Annex IIIA, point 7.3) Default value: 100% Acceptable exposure scenarios (including method of calculation) Operator Acceptable for proposed uses Workers Acceptable for proposed uses Bystanders Acceptable for proposed uses Classification and proposed labelling (Annex IIA, point 10) with regard to toxicological data Xi; R 41 BA: benzoic acid; SB: sodium benzoate.

7 - 4 - Addendum 1 to the draft assessment report of benzoic acid 18 June 2003 VOLUME 3 B.2 Physical and chemical properties B.2.2 Physical, chemical and technical properties of the plant protection products (Annex IIIA 2) Section (Annex point) B (IIIA 2.3) B (IIIA 2.5) B (IIIA 2.5) Study Method Results Comment/Conclusion Reference Flash point EEC A 9 28 C Study not performed according to GLP, acceptable. Classification of the formulation: R 10 Flammable Kinematic viscosity Dynamic viscosity Brockfield viscometer (OECD 114) 6.9 mpa s Study not performed according GLP, acceptable. Hahn, W. (1994), CHE AFP (1996), CHE

8 - 5 - Addendum 1 to the draft assessment report of benzoic acid 18 June 2003 B.2.3 References relied on Annex point/ reference number Author(s) Year Title source (where different from company) report no. GLP or GEP status (where relevant), published or not BBA registration number AIIIA-2.4 AFP GmbH 1996 Menno Florades Batch No Not GLP, unpublished CHE Data protection claimed Y/N Y Owner MEN B.4 Proposals for the classification and labelling Classification of the formulation: R 10 Flammable B.6. Toxicology and metabolism Introduction The objective of this addendum is to adress the inhalative toxicity of benzoic acid in greater detail and to report a sensitization study with the formulation which has been performed only recently and is not included in the original draft assessment report, therefore. These data do not alter the current and, in general, favourable health assessment of benzoic acid. Furthermore, the list of endpoints had to be amended taking into consideration the outcome of a subacute inhalation study with the active ingredient on rats. When the draft assessment report was finished in 2000, this study had been available as an abstract only and could not be fully evaluated. B.6.2 Acute toxicity including irritancy and skin sensitization (Annex IIA 5.2) B Acute inhalative toxicity studies with benzoic acid The only available acute inhalation study reported in the draft assessment report (Bio-Fax, 1973) does not comply to current guideline requirements. It is a rather old and poorly reported experiment using only a very low concentration of mg benzoic acid/l. Furthermore, the animals were exposed to the test atmosphere for one hour only instead of four as required. Therefore, this study is considered supplementary only and not sufficient to facilitate reliable and comprehensive assessment of an inhalative hazard or risk. Accordingly, a new acute inhalation study should have been required. However, since studies of this type cause severy pain and distress for the animals on study and since there is no evidence of adverse effects of benzoic acid upon inhalative exposure coming from the long-lasting use of this compound, other existing data may provide an alternative to evaluate this toxicological endpoint and to avoid an additional test on mammals.

9 - 6 - Addendum 1 to the draft assessment report of benzoic acid 18 June 2003 A GLP-compliant subacute inhalative study had been performed and was briefly mentioned in the draft assessment report already. In principle, one could expect that such a study (if wellconducted) could be also suitable for assessing toxicological effects after single exposure. An exposure time of 6 hours per day even exceeds the current guideline requirements. When the draft assessment report was prepared, this study was available as an abstract only because it was not part of the original dossier submitted by the notifier. Thus, succesful efforts were taken to receive the original study report and evaluate it (see below). In this study, the LC50 for a single exposure over 6 hours was clearly above 1.2 mg/l. Thus, hazard classification for acute inhalative toxicity is not warranted and a new acute inhalation study with benzoic acid not necessary since the endpoints "mortality" and "clinical signs" in single exposure situation have been adequately addressed. The more or less invalid data from the only available acute inhalation test suggesting an LC50 higher than mg/l (one-hour exposure, see draft assessment report) should be replaced. B.6.3 Short-term toxicity (Annex IIA 5.3) B Short term toxicity studies in rats B Inhalative study, Rat Report: Rop et al (1981): Four week subacute inhalation toxicity study of Benzoic acid in rats. International Research and Developmental Company (IRDC), Mattawan, Michigan, USA, Report no on behalf of Velsicol Chemical Corp., Chicago, Illinois, USA; unpublished. Date of experimental work: GLP: Yes. (Self-certification of the performing laboratory. No formal GLP certificate included, however, it is stated in the report that testing had been performed in accordance with U.S. GLP regulations adopted in 1979.) QAU statement included. Guideline and deviations: Not applicable. The study is considered acceptable. Remark: When the draft assessment report was prepared, information about this study was available as an abstract only (see B ). However, since then, the original study report from the IRDC laboratory has been submitted by the Dutch company DSM Food Specialties (Delft, The Netherlands) to the Scientific Committee on Animal Nutrition (SCAN) to support the risk assessment on residues that may occur in human food derived from animals (in particular pigs) receiving benozoic acid in their diet in concentrations up to 1%. Addition of benzoic acid to pig ration is assumed to exhibit some positive effects on the health of the animals and on food conversion. Furthermore, it lowers urine ph and, thus, might decrease the emission of ammonia in pig excreta.

10 - 7 - Addendum 1 to the draft assessment report of benzoic acid 18 June 2003 Already in 1981, the report had been provided by the owner Velsicol Corp. to the U.S.EPA since, according to the company, "... an apparent compound related effect was reported in the lungs at all dose levels tested." It is not known in which way the EPA responded to that submission. After the SCAN opinion has been published in 2002, the complete study became available also to the RMS for evaluation. Later on, a copy of the original report was submitted on request of the RMS by the notifier which received it from DSM. According to DSM, this report is "public property" and data protection could not be claimed. Material and Methods: Groups of 10 male and 10 female CD rats (Charles River, Portage, Michigan, USA) were exposed to a dust aerosol of benzoic acid over a period of 4 weeks for 6 hours per day on 5 days per week. A control group of the same size was included. Benzoic acid technical (purity not given) had been provided by the manufacturer Velsicol Corp. The intended concentrations of 0.02, 0.2 and 2.0 mg/l air were difficult to achieve in the dust generating system used. The actual concentrations in the test chamber (whole-body exposure conditions) were measured to be 0.025, 0.25 and 1.2 mg/l. Particle size was analysed and found to be in the range of 4.4 to 5.2 µm with a mean aerodynamic diameter of 4.7 microns. The animals were observed for mortality and occurrence of clinical signs. Their body weight development was monitored and a full range of hematological and clinical chemistry examinations performed at study termination as well as a comprehensive gross pathological evaluation followed by histopathology of selected organs with special emphasis on the respiratory tract. Organ weights were determined. For interpretation of the results, appropriate statistical methods like ANOVA, Bartlett s and t- test were applied. Findings: At the highest concentration, one male and one female rat died on exposure days 15 or 6, respectively. More detailed information concerning these deaths is lacking. Clinical signs became apparent by reddish discharge around the nares from day 4 onwards at concentrations of 1.2 and 0.25 mg/l and from day 13 in the low dose group. In contrast, no such observation was made in the control animals. Body weight gain was compromised in both sexes at the top dose level only. Changes in hematological parameters were confined to the high dose group and compiled a decrease in platelet count, in mean corpuscular volume and in mean corpuscular hemoglobin whereas clinical chemistry did not reveal evidence of treatment-related effects. The absolute and relative (organ-to-brain ratio) liver weight was significantly lowered in high dose males and a similar trend was apparent in the females of this group. In female rats, the absolute and relative kidney weight was decreased at 0.25 and 1.2 mg/l showing a clear doseresponse. Also in females, the weight of the lungs (with trachea) was diminished at the top dose level. At necropsy, no gross pathological findings were recognised that could be related to treatment. However, histopathology provided a clearly dose-related increase in extent and intensity of interstitial inflammatory cell infiltrates as well as in the incidence and degree of interstitial fibrosis in all treated groups. Conclusions: The subacute inhalative study in rats revealed evidence of systemic toxicity at least at the highest tested concentration of 1.2 mg/l air and, taking into account the lower kidney weight, probably also at the mid dose level of 0.25 mg/l. Histopathological and clinical signs of respiratory tract irritation were seen in all treated groups confirming the irritating potential of this active substance. A NOAEL could not be established.

11 - 8 - Addendum 1 to the draft assessment report of benzoic acid 18 June 2003 A new acute inhalation study with benzoic acid is not considered necessary since the endpoints "mortality" and "clinical signs" in single exposure situation have been adequately addressed as part of this subacute study. Hazard classification for acute inhalative toxicity is not warranted because the two deaths at the highest concentration occurred after a number of subsequent exposures only and clinical signs of irritiation were not noted before exposure day 4. The LC50 for a single exposure over even 6 hours was clearly above 1.2 mg/l. B.6.11 Acute toxicity including irritancy and skin sensitization of preparations (Annex IIIA 7.1) B Skin sensitization (formulation) Since this was a clear data gap before, a Magnusson-Kligman test was performed after the draft assessment report had been finished and submitted on request of the RMS. No evidence of a potential of the product "MENNO Florades" to induce skin sensitization was obtained. In the following, this study is reported in detail. Report: Bien, E. (2003): Maximisation sensitisation test according to Magnusson & Kligman of "VP- FL/5" (commercial name: MENNO Florades) in the Guinea pig. Harlan Bioservice for Science GmbH, Walsrode/Germany; Study no on behalf of MENNO Chemievertriebsges. MbH, Norderstedt, Germany; unpublished. Dates of experimental work: 19 November December GLP: Yes (certified by Niedersächsisches Umweltministerium in 1999). QAU statement included. Guidelines: OECD TG 406. The study is considered acceptable. Material and methods: Male and female, SPF-bred Pirbright White Guinea pigs (source: Charles River Deutschland GmbH, Kißlegg, Germany) were used in a Maximisation test according to Magnusson and Kligman. Following a range-finding test employing one Guinea pig per sex, 10 treatment and 5 control animals were used in the main study and additional 5 control animals for rechallenge exposure. For the intradermal injection in the induction phase, the formulation MENNO Florades containing benzoic acid as active ingredient was diluted in either aqua ad injectabilia (AI) or in a mixture of AI with Freund s complete adjuvant (FCA) to give a final concentration of 5%. Each test animal received three pairs of intradermal injections (0.1 ml) in the clipped intrascapular region on either side of the spine. The test animals were administered FCA (50%) in AI, MENNO Florades (5%) in AI and MENNO Florades (5%) in FCA/AI. The control animals were treated likewise but without the test article. Dermal induction after seven days was performed for 48 hours using the undiluted test article after reclipping and pre-treatment of the skin with 10% sodium lauryl sulfate to induce a mild inflammation. Challenge was made by 24-hour exposure to the undiluted test article and to AI on the flanks under an occlusive dressing. For clarification of equivocal findings, rechallenge was conducted in the same way but 12 days later in the test animals and in 5 naive control

12 - 9 - Addendum 1 to the draft assessment report of benzoic acid 18 June 2003 animals. In this part of the study, the test article was applied in concentrations of 50, 25, and 12.5 %. Skin observations were made 24 and 48 hours after patch removal. Skin responses were graded according to Draize. The Guinea pigs were weighed before treatment and at sacrifice. A positive control substance was not included in this study, however, the sensitivity of the test system and the reliability of the experimental technique were stated in the original report to be assessed at least every six months in this laboratory in a confirmatory trial using benzocaine. Findings: There were no unscheduled deaths throughout the study and body weight was not impaired. In the induction phase, no skin reactions occurred. At 24 hours following dermal challenge, erythema and oedema were observed in most treatment and control animals. These effects had become even more pronounced when evaluated after 48 hours and all animals on study were affected now. Apart from two treatment group animals with eschar formation, there was no difference between the groups. Following re-challenge, no skin reactions were observed neither in the animals receiving the test article nor in the control group. Conclusion: A potential for delayed skin irritation of the formulation MENNO Florades became apparent which is in line with the corrosive properties observed in the eye irritation test. In contrast, no evidence of skin sensitization was obtained in this study. References relied on Rop et al (1981). Four week subacute inhalation toxicity study of Benzoic acid in rats. International Research and Developmental Company (IRDC), Mattawan, Michigan, USA, Report no , unpublished. GLP: yes. Bien, E. (2003): Maximisation sensitisation test according to Magnusson & Kligman of "VP- FL/5" (commercial name: MENNO Florades) in the Guinea pig. Harlan Bioservice for Science GmbH, Walsrode/Germany; Study no , unpublished. GLP: yes