Reaction products of diphenylamine with nonene, branched

Long-term toxicity to aquatic invertebrates

Description of key information

Toxic effects were observed in a Daphnia reproduction study according to OECD 211.

Additional information

The long-term toxicity on aquatic invertebrates was investigated with Daphnia magna, in a GLP guideline study according to OECD 211 [2019].  Since the test item is an uvcb substance and poorly soluble, saturated solutions were prepared withwater accommodated fractions (WAF)under consideration of Guidance document on aquatic toxicity testing of difficult items and mixtures, OECD series on testing and assessment number 23, 2019.: A slow stirring procedure was applied for 72 ± 2 hour at room temperature. After a separation phase of 30 minutes at room temperature, the aqueous phase or WAF was removed by siphoning (from the approximate bottom of the glass flask). The study was conducted as a semi-static limit test with a nominal loading rate of 1.98 - 2.96 - 4.45 - 6.67 - 10 mg/L and daily renewal of the test media.

Samples for chemical analysis of the actual test concentration were taken from various intervals during the test of both fresh and old solutions. The results of analysis of the samples via LC-MS/MS showed that it was difficult if not impossible to quantify the test concentrations.Only the monoalkylated isomers could be quantified. Measured concentrations were either extremely low or generally even below the limit of quantification (< 1μg/L). It was concluded that these results could not be used to base test concentration upon. Thus, results of the present study were based on the loading rates initially prepared.

The test item induced adult mortality of 50% after 21 days in the nominal loading rate 10.0 mg/L and 10% in the loading rates 2.96 – 4 45 – 6 67 mg/L. OECD guideline 211 concedes a mortality rate of control Daphnia up to 20% (without invalidating such a test); insofar any mortalities in the test trials up to that percentage are equally to be considered insignificant, particularly as the tolerated mortality rate in the present study is constant over three exposure levels.A statistically significant reduction of the reproductive output in comparison to the reproductive output in the control was determined at the nominal loading rates of 6.67 and 10.0 mg/L.

However, the reproduction rate of all parent Daphnia which died was comparable to the reproduction rate of surviving parental Daphnia. In addition, reproduction rates of treated Daphnia were also similar to the control group’s reproduction rate. Therefore, it can be assumed that a major reason for lower overall reproduction is the mortality of the parent Daphnia.

ELR10 reproduction 21d: 4.12 mg/L nominal loading rate (WAF)

ELR50 reproduction 21d: > 10 mg/L nominal loading rate (WAF)