zinc, 5,5'-azobis-2,4,6(1H,3H,5H)-pyrimidinetrione complexes and melamine

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Male and female rats received daily 0, 100, 330 or 1000 mg/kg bw/day formulated in 0.5 % carboxy methylcellose by gavage over a period of 28 days. The examinations were done according to OECD TG 407 under GLP conditions. Considering male and female reproductive organs no adverse effects were reported. Therefore the NOAEL (reproductive organs) is established to be 1000 mg/kg bw/day

Link to relevant study records

Reference

Endpoint:

toxicity to reproduction

Data waiving:

other justification

Justification for data waiving:

other:

Reproductive effects observed:

not specified

Effect on fertility: via oral route

Endpoint conclusion:

no study available

1 000

Study duration:

subacute

Species:

rat

Quality of whole database:

No adverse effects are observed
Azo zinc complex pigment - melamine compound is practically non-toxic following acute oral and dermal application (LD50 > 2000 mg/kg bw), is only slightly irritating to the skin and eyes, does not show sensitizing potential and developed no mutagenic activity in the in-vitro tests (Chromosome aberration test in CHL/IU and Ames test). In the subacute oral rat study no animal died during the treatment period and in the recovery period thereafter. Azo zinc complex pigment - melamine compound was well tolerated with a NOAEL of 1000 mg/kg bw(day (limit dose)

Additional information

Azo Zinc Complex Pigment – Melamine compound shall be registered according to Art 10 of Regulation EC No. 1907 / 2006 (REACH) for annual production of 10 – 100 tons (ANNEX VIII) and information on possible reproductive toxicity is required; in this tonnage band especially a screening study according to OECD TG 421/422 should be available.

However, for Azo Zinc Complex Pigment – Melamine Compound there is no screening study available to evaluate reproductive toxicity.

In general, if no screening study is available, it is an accepted procedure to fulfill this requirement considering the available repeated dose toxicity study which should provide careful examination of reproductive organs, in conjunction with a developmental toxicity study according to OECD TG 414.

This procedure was followed by the applicant for Azo Nickel Complex Pigment - Melamine Compound and ECHA reviewed and accepted to conduct a developmental toxicity study (ECHA Final Decision, dated 2015-03-23, Decision Number TPE-D-2114294432-48-01/F; Decision on testing proposal(s) set out in a registration pursuant to Article 40(3) of Regulation (EC) No. 1907/2006: For nickel, 5,5’-azobis-2,4,6(1H,3H,5H)-pyrimidinetrione complexes and melamine, List No. 939-379-0, registration number: 01-2119970317-33-000)): .

It is proposed to proceed similar for the Azo Zinc Complex Pigment – Melamine Compound and to evaluate the available repeated dose toxicity study with Azo Zinc Complex Pigment - Melamine Compound for effects on reproductive organs and to consider a Read-Across with “Azo Nickel Complex Pigment – Melamine Compound” for developmental toxicity see the respective section).

1. Justification to evaluate reproductive organs in repeated dose toxicity studies for assumption on fertility

As confirmed by literature (Mangelsdorf et al. 2003, Ulbrich & Palmer 1995, Janer et al. 2007, Dent 2007) histopathological examinations in repeated dose toxicity are of high value and of high sensitivity for evaluation of reproductive toxicity. Therefore, at least for fertility assessment, repeated dose toxicity studies showing no adverse effect should be taken into account. Also it is agreed that histopathological changes on the reproductive organs in repeated dose toxicity studies are indicative of effects on fertility. Therefore repeated dose toxicity studies should be considered sufficient information to evaluate toxicity on fertility if histological examination of the reproductive organs is covered by the repeated dose toxicity study and the mode of action of the test substance does not give evidence for a specific toxicity

Azo zinc complex pigment - melamine compound is practically non-toxic following acute oral and dermal application (LD50 > 2000 mg/kg bw), is only slightly irritating to the skin and eyes, does not show sensitizing potential and developed no mutagenic activity in the in-vitro tests (Chromosome aberration test in CHL/IU and Ames test). In the subacute oral rat study no animal died during the treatment period and in the recovery period thereafter. Azo zinc complex pigment - melamine compound was well tolerated. The evidence of compound colored feces was noted in all dosage groups during administration period but disappeared during recovery period. No treatment related adverse effects could be determined during hematological and blood biochemical analysis or gross and histopathological examinations No adverse effects were noted from reproductive organs in these groups A NOAEL of 1000 mg/kg bw/day in male and female rats is the result of this subacute oral study.For the required developmental toxicity study (rat, oral) according to OECD TG 414 see the respective section.

Overall, based on the lack of effects on reproductive organs in the subacute toxicity study with Azo Zinc Complex Pigment - Melamine Compound there is no evidence that reproductive toxicity might occur. Considering this in conjunction with the developmental rat study with the surrogate Azo Nickel Complex Pigment - Melamine Compound (see the respective section)according to OECD TG 414 the requirements of the REACH Regulation for this tonnage band are fulfilled.

References

Mangelsdorf et al. 2003:

Some aspects relating to the evaluation of the effects of chemicals on male fertility. Regulatory Toxicology and Pharmacology 36, 69-98.

Ulbrich & Palmer 1995:

Detection of effects on male reproduction - a literature survey. J. Am. College of Toxicology 14, 293-327.

Janer et al. 2007:

A retrospective analysis of the added value of the rat two-generation reproductive toxicity study versus the rat subchronic toxicity study. Reproductive Toxicology 24, 103-113.

Dent, 2007:

Strength and limitations of using repeated-dose toxicity studies to predict effects on fertility. Regulatory Toxicology and Pharmacology 48, 241-258.

Justification for selection of Effect on fertility via oral route:
No adverse effects observed in general and on reproductive organs in a subacute oral rat study which was performed according to the respective OECD test guideline and therefore evaluated with Klimisch score 1

Effects on developmental toxicity

Description of key information

There is no developmental toxicity study available using Azo Zinc Complex Pigment – Melamine Compound as required if no screening reproductive toxicity study is available. Therefore the surrogate molecule Azo Nickel Complex Pigment - Melamine Compound was taken into account to fill the data gap.

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

GLP compliance:

yes

Abnormalities:

not specified

Developmental effects observed:

not specified

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Additional information

Azo Zinc Complex Pigment – Melamine compound shall be registered according to Art 10 of Regulation EC No. 1907 / 2006 (REACH) for annual production of 10 – 100 tons (ANNEX VIII) and information on possible reproductive toxicity is required; in this tonnage band especially a screening study according to OECD TG 421/422 should be available.

However, for Azo Zinc Complex Pigment – Melamine Compound there is no screening study available to evaluate reproductive toxicity.

In general, if no screening study is available, it is an accepted procedure to fulfill this requirement considering the available repeated dose toxicity study which should provide careful examination of reproductive organs, in conjunction with a developmental toxicity study according to OECD TG 414.

This procedure was followed by the applicant for Azo Nickel Complex Pigment - Melamine Compound and ECHA reviewed and accepted to conduct a developmental toxicity study (ECHA Final Decision, dated 2015-03-23, Decision Number TPE-D-2114294432-48-01/F; Decision on testing proposal(s) set out in a registration pursuant to Article 40(3) of Regulation (EC) No. 1907/2006: For nickel, 5,5’-azobis-2,4,6(1H,3H,5H)-pyrimidinetrione complexes and melamine, List No. 939-379-0, registration number: 01-2119970317-33-000)): .

It is proposed to proceed similar for the Azo Zinc Complex Pigment – Melamine Compound and to evaluate the available repeated dose toxicity study with Azo Zinc Complex Pigment - Melamine Compound for effects on reproductive organs (see the respective sections) and to consider a Read-Across with “Azo Nickel Complex Pigment – Melamine Compound” for developmental toxicity.

There is no developmental toxicity study available using Azo Zinc Complex Pigment – Melamine Compound as required if no screening reproductive toxicity study is available.

Taking into account the specific rules in Regulation (EC) No 1907/2006 (REACH) ANNEX XI 1.: Testing does not appear scientifically necessary; section 1.5: Grouping of substances and read across approach, this procedure can be considered because there is an analogue compound Azo Nickel Complex Pigment - Melamine Compound which can be taken as surrogate. Azo Nickel Complex Pigment – Melamine Compound is already registered in 2013.

A comparison between Azo Zinc Complex Pigment – Melamine compound and Azo Nickel Complex Pigment – Melamine compound show that both compounds have similar physico-chemical properties and similar result in the available toxicity studies indicating that both compounds follow the same pattern (e.g. mode of action):

Almost all available investigations to evaluate the toxicological properties of both compounds are guideline studies performed under GLP conditions. It can be concluded that there is reliable evidence that these compounds have similar toxicological properties: both compounds are of low acute toxicity, do not induce skin or eye irritation or sensitization reactions. Both substances do not show mutagenic activity in bacteria and do not induce clastogenicity in in-vitro tests. Following repeated dosing of up to and including 1000 mg/kg bw/day (limit dose) to rats over a period of 28 days neither Azo Nickel Complex Pigment - Melamine Compound nor Azo Zinc Complex Pigment - Melamine Compound caused adverse effects in rats leading to NOAELs(general tox.) of 1000 mg/kg bw/day.

Based on this consideration there is reliable evidence that both compounds will yield similar results in the developmental toxicity studies.

Hence, for Azo Nickel Complex Pigment - Melamine Compound the required fertility assessment could not be performed because there was no screening study available at the time point of registration. Thus, the accepted surrogate procedure (evaluation of a 28-day repeated dose toxicity study in conjunction with a developmental study) was taken into account. A thoroughly performed repeated dose toxicity study was available (NOAEL 1000 mg/kg bw/day, limit dose) but no developmental toxicity study exists at the time point of registration Therefore, a test proposal for a developmental toxicity study was made. This proposal was approved by ECHA (Final Decision: 2015-03-23, Decision Number TPE-D-2114294432-48-01/F; Decision on testing proposal(s) set out in a registration pursuant to Article 40(3) of Regulation (EC) No. 1907/2006: For nickel, 5,5’-azobis-2,4,6(1H,3H,5H)-pyrimidinetrione complexes and melamine, List No. 939-379-0, registration number: 01-2119970317-33-000)): .

The investigation on probable developmental toxicity with Azo Nickel Complex Pigment Melamine Compound according to OECD TG 414 in rats dosed orally has started with a pilot study (dosing: 0 (negative=vehicle control), 250, 500 or 1000 mg/kg bw/day suspended in Ethanol/Solutol HS 15/Tap water (10/40/50 v/v/v; main study dosing depends on the pilot study result). The main study is planned to start soon and the report will be available before March 2016 at latest.

In conclusion, considering the specific rules in Regulation EC No 1907/2006 (REACH) ANNEX XI 1.: Testing does not appear scientifically necessary ; section 1.5: Grouping of substances and read across approach and the similarity in physico-chemical properties and in results in the available toxicity studies between Azo zinc complex pigment melamine compound and Azo Nickel complex pigment melamine compound indicating that both compounds follow the same pattern (e.g. mode of action), it seems to be a legal strategy to replace the missing developmental toxicity study of Azo zinc complex pigment-melamine compound with the incoming results of a developmental toxicity study of the analogue substance Azo Nickel complex pigment melamine compound.

Overall, Azo Zinc Complex Pigment – Melamine compound shall be registered according to Art 10 of Regulation EC No. 1907 / 2006 (REACH) for annual production of 10 – 100 tons (ANNEX VIII) and information on possible reproductive toxicity is required; in this tonnage band especially a screening study according to OECD TG 421/422 should be available.

However, for Azo Zinc Complex Pigment – Melamine compound there is no screening study available to evaluate reproductive toxicity. However it could be shown that it is justified to take into account the available repeated dose toxicity study with Azo zinc complex pigment melamine compound and to consider the developmental toxicity study of Azo Nickel complex pigment melamine compound as surrogate for the missing data.

Justification for selection of Effect on developmental toxicity: via oral route:
in accordance to ANNEX VIII Section 8.7.1. column 2 of Regulation (EC) No 1907/2006 (REACH) a screening for reproductive/developmental toxicity (OECD421 or 422) does not need to be conducted if a prenatal developmental toxicity is available. A test according to OECD TG 414 (Developmental toxicity: rat, oral) is proposed to fulfill this requirement

Toxicity to reproduction: other studies

Additional information

This study was performed to investigate the systemic toxicity on male and female rats followed 28 consecutive days repeated oral dosing of Azo zinc complexpigment - melamine compound via gavage at dose levels of 0, 100, 330, and 1000 mg/kg bw/day suspended in 0.5% carboxy methylcellulose. Recovery groups (0 and 1000 mg/kg bw/day) were maintained without dosing for a further 14 days after administration period to evaluate the reversibility of any potential effects. The study was conducted in compliance with OECD TG 407 under GLP conditions.

No animal died during the treatment period and in the recovery period thereafter. Azo zinc complexpigment - melamine compound was well tolerated. The evidence of compound colored feces was noted in all dosage groups during administration period but disappeared during recovery period. This observation indicated that absorption of Azo zinc complexpigment - melamine compound is limited. No treatment related adverse effects could be determined during hematological and blood biochemical analysis or gross and

histopathological examinations. Therefore, the NOAEL (general toxicity) of Azo zinc complex pigment - Melamine compound is considered to be 1000 mg/kg bw/day. Considering male and female reproductive organs no adverse effects were reported. Therefore the NOAEL (reproductive organs) is established to be 1000 mg/kg bw/day.

Justification for classification or non-classification

Based on the available data no classification or labelling is required.