N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine

Long-term toxicity to aquatic invertebrates

Description of key information

The chronic toxicity of 4 -hydroxydiphenylamine to Daphnia magna was investigated in a static test according to Council Regulation (EC) No 440/2008, Method C.20 'Daphnia magna Reproduction Test'' (2008), which equals to the OECD Test guideline 211 (Daphnia magna Reproduction Test; 1998). After 21 days a NOEC of 0.028 mg/L was determined (Currenta, 2010). A further test performed with p-hydroquinone yieled a NOEC of 0.0029 mg/L, expressed in 6PPD equivalents of 0.007 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.007 mg/L

Additional information

Justification for performing the read across approach with 4 -Hydroxydiphenylamine and p-Hydroquinone:

4-Hydroxydiphenylamine (4 -HPDA) is not the hydrolysis product from 77PD but it is considered as similar to the primary hydrolysis product, 1,4 -dimethylpentylamino-p-phenol. A secondary hydrolysis product is p-hydroquinone.

The lowest effect value in long-term tests was found for p-hydroquinone (0.007 mg/L, expressed in 77PD equivalents) which is lower than the value for 4-HDPA (0.028 mg/L).Although p-hydroquinone is a secondary hydrolysis product of 77PD, it was chosen as a source of key value as it shows the lowest effect concentrations of the degradation products and is therefore the worst case.

A chronic daphnia test accoding to USEPA 2002 is available for tyre wear particles (TWP) (Marwood 2010).TWPs are produced containing antioxidants like 77PD in a concentration of about 1%. Ceriodaphnia dubia showed no biological significant effect in a 32d study concerning survival, growth and reproduction.