A mixture of: N,N-diethylpropane-1,3-diamine 6-methyl-2-(4-(2,4,6-triaminopyrimidin-5-ylazo)phenyl)benzothiazole-7-sulfonate; 2,2-iminodiethanol 6-methyl-2-(4-(2,4,6-triaminopyrimidin-5-ylazo)phenyl)benzothiazole-7-sulfonate; 2-methylaminoethanol 6-methyl-2-(4-(2,4,6-triaminopyrimidin-5-ylazo)phenyl)benzothiazole-7-sulfonate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route

Dose descriptor:

NOAEL

300 mg/kg bw/day

Additional information

In the key study, that was performed according to OECD guideline 421 in compliance with GLP, Direct Yellow 166 was administered by daily oral gavage to male and female Wistar Han rats at dose levels of 100, 300 and 1000 mg/kg bw/day (BASF SE, 2011). Males were exposed for 2 weeks prior to mating, during mating, and up to termination (for 30 days). The females were exposed for 2 weeks prior to mating, during mating, during post-coitum, and at least 4 days of lactation (for 42-55 days). In parental animals clinical signs, food consumption and body weight changes were observed at the high dose level. Histopathologically, a normal cyclic activity in the reproductive system of all females at 1000 mg/kg bw/d was observed. However, at 1000 mg/kg bw/d, eight out of ten females did not become pregnant. Neither implantation sites nor macroscopically visible corpora lutea were noted in these females. Two out of ten females at 1000 mg/kg bw/d showed some evidence of pregnancy but delivered no live offspring. One of the pregnant females had only one corpora luteum. The other pregnant female had a near normal number of 11 corpora lutea. Both pregnant females had only one implantation site but showed placental tissues and/or fluid and cell debris in the uterus. One pregnant female showed moderate mucification of the vaginal epithelium and fluid with cell debris in the vagina as well. No reproduction toxicity was observed at 100 and 300 mg/kg bw/d (i.e. mating, fertility and conception indices, precoital time, and numbers of corpora lutea and implantation sites were normal). The parental systemic NOAEL was determined to be 300 mg/kg bw/d, the reproductive NOAEL was determined to be 300 mg/kg bw/d.

Short description of key information:
In a reproduction/developmental toxicity screening test (OECD TG 421) with Direct Yellow 166 in rats by oral gavage (BASF SE, 2011) the following NOAELs were derived: Parental systemic NOAEL: 300 mg/kg bw/d; Reproduction NOAEL: 300 mg/kg bw/d; Developmental NOAEL: 300 mg/kg bw/d (at 1000 mg/kg bw/d, no pups were delivered).
Two females at 1000 mg/kg bw/d became pregnant out of ten mated/paired females, resulting in a significantly reduced fertility and conception index. None of these pregnant females delivered live offspring, resulting in a gestation index of 0%. No corpora lutea were found in the non-pregnant females at 1000 mg/kg bw/d. One of the pregnant females had only one corpora luteum. The other pregnant female showed 11 corpora lutea. Both pregnant females had only one implantation site. Mating index and precoital time were normal at all dose levels. Fertility and conception indices and number of corpora lutea and implantation sites were normal at 100 and 300 mg/kg bw/d.

Effects on developmental toxicity

Description of key information

In a reproduction/developmental toxicity screening test (OECD TG 421) with Direct Yellow 166 in rats by oral gavage (BASF SE, 2011)  the following NOAELs were derived: Parental systemic NOAEL: 300 mg/kg bw/d; Reproduction NOAEL: 300 mg/kg bw/d; Developmental NOAEL: 300 mg/kg bw/day (at 1000 mg/kg bw/d, no pups were delivered).
No developmental toxicity was observed at 100 and 300 mg/kg bw/d (i.e. gestation index and duration, parturition, maternal care and early postnatal pup development (consisting of mortality, clinical signs, body weight and macroscopy) were normal. At 1000 mg/kg bw/d, no pups were delivered and hence no assessment of developmental toxicity could be made.

Effect on developmental toxicity: via oral route

Dose descriptor:

NOAEL

300 mg/kg bw/day

Additional information

In the key study, that was performed according to OECD guideline 421 in compliance with GLP, Direct Yellow 166 was administered by daily oral gavage to male and female Wistar Han rats at dose levels of 100, 300 and 1000 mg/kg bw/d (BASF SE, 2011). Males were exposed for 2 weeks prior to mating, during mating, and up to termination (for 30 days). The females were exposed for 2 weeks prior to mating, during mating, during post-coitum, and at least 4 days of lactation (for 42-55 days). In parental animals clinical signs, food consumption and body weight changes were observed at the high dose level. A relationship to treatment can not be excluded. No developmental toxicity was observed at 100 and 300 mg/kg bw/d (i.e. gestation index and duration, parturition, maternal care and early postnatal pup development (consisting of mortality, clinical signs, body weight and macroscopy) were normal. At 1000 mg/kg bw/d, no pups were delivered and hence no assessment of developmental toxicity could be made. The parental NOAEL was determined to be 300 mg/kg bw/d, the developmental NOAEL was determined to be 300 mg/kg bw/d.

Justification for classification or non-classification

A reproduction/developmental toxicity screening test according to OECD TG 421 in compliance with GLP is available for assessment of toxicity to reproduction. Based on the significantly reduced fertility and conception index, and a gestation index of 0% at the high dose level (1000 mg/kg bw/d) in this study, the classification of the substance as R62 (Repr. Cat. 3) according to EU Directive 67/548/EEC and in Repro Cat. 2 according to CLP Regulation EC/1271/2008 is proposed.