Phenol, 4-nonyl-, branched

Long-term toxicity to fish

Description of key information

The selected key study, Watanabe et al (2017) exposed Japanese medaka,Oryzias latipes, to nonylphenol for 16 weeks in a flow-through system. The key value is a NOEC for fertilised eggs, F0 and F1 generations of 0.000127 mg/l or 1.27µg/L.

For the marine environment, the only species with chronic toxicity data is the Flounder, Pleuronectes americanus. This result is based on the acute to chronic ratio (ACR) calculated from the acute test result by Lussier et al (2000) using the most conservative ACR determined for the fish species Onchorynchus mykiss. This method determined a NOEC value of 0.00046mg/l.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0 mg/L

Marine water fish

Marine water fish

Effect concentration:

0 mg/L

Additional information

The study by Watanabe et al (2017) was selected as the key study because of the high level of documentation and this study provided the lowest NOEC value for standard test endpoints such as growth, reproduction and survival that indicated Oryzias latipes was more sensitive than other standard test species, such as Pimephales promelas.  

Several studies including nine different species of freshwater fish exposed to nonylphenol were found to be reliable (Klimisch 1 or 2). The studies included tests with preferred test species O. latipes, P. promelas, Danio rerio and Oncorhynchus mykiss, but reliable studies with marine fish species were not found. Test duration ranged from 21 to 365 days with NOEC endpoints reported for survival, growth, and reproduction (also expressed as fecundity or fertility). The range of NOEC values for survival were comparable and ranged from >0.0019 mg nonylphenol/L for O. latipesto 0.0775 mg nonylphenol/L for P. promelas (Brook 1993) compared to a NOEC range for growth from 0.006 mg nonylphenol/L for O. mykiss (Brooke 1993) to 0.038 mg nonylphenol/L for Pimephales promelas (Brooke 1993b), and a NOEC range for fertility of 0.0082 to 0.051 mg nonylphenol/L reported by Yokota et al (2001) and Kang et al (2003), respectively, for O. latipes. Based on the data available, inhibition of growth and reduction in reproduction (fertility) appeared to be an equally sensitive response to exposure of nonylphenol to fish. Of the species tested, the preferred species O. mykissand and O. latipes, appeared to be equally sensitive to nonylphenol exposure for the growth endpoints and more sensitive than P. promelas for the same endpoint.

The chronic toxicity of nonylphenol to Flounder, Pleuronectes americanus, was also assessed by application of the acute to chronic ratio (ACR). The most conservative ACR determined based on acute and chronic data for the Onchorynchus mykiss was applied to the Flounder acute study data from the Lussier et al study (2002). The NOEC was calculated at 0.0005mg/l. This is the only study that relates to marine species.