5-[(2-hydroxyethyl)amino]-o-cresol

Long-term toxicity to aquatic invertebrates

Description of key information

The purpose of the study was to determine the long term effect over 21 days of the test item on Daphnia magna, according to the OECD 211 guideline and following GLP. Ten daphnids, held individually, were used per concentration level and control. At test start the daphnids were 2 to 24 hours old. The study was carried out under semi-static conditions with a medium renewal three times per week. Aim of the test was to assess the effects on the reproduction capacity and other test item-related effects or parameters such as the intrinsic rate of the natural increase, first appearance of living juveniles, occurrence of aborted eggs and stillborn juveniles, adult mortality, body length and dry weight of the parental daphnids.

Nominal concentrations of the test item were selected based on the results of an acute immobilization test as follows: 0.0316 - 0.100 - 0.316 - 1.00 - 3.16 mg/L. The test item concentrations were analytically verified via LC-MS/MS in fresh media at the start of the exposure intervals on days 0, 10, 17 (0 hours) and in old media at the end of the exposure intervals on days 3, 12, 19 (48 or 72 hours, respectively) in all concentration levels with surviving parental daphnids and the control. The measured concentrations of the test item in fresh media at the start of the respective exposure intervals (0 hours) were in the range of 91 to 118% of the nominal concentrations. At the end of the respective exposure intervals (48 and 72 hours), the measured test item concentrations in the old media were in the range of 23 to 75% of the nominal concentrations. Since the measured test item concentrations were not within ± 20% of the nominal concentrations, the geometric mean measured concentrations were calculated and used for estimation of the effect-concentrations. The geometric mean measured test item concentrations are: 0.0171 - 0.0572 – 0.191 – 0.724 - 2.46 mg/L.

The environmental conditions were within the acceptable limits. The validity criteria of the test guideline were met.

The effects on reproduction were evaluated based on the reproduction per introduced parent animal.

All the endpoints are based on the geometric mean measured concentrations of the test item and are summarised below:EC10 Reproduction= 1.03 mg/L; EC50 Reproduction>2.46 mg/L; LOEC Reproduction=2.46 mg/L; NOEC Reproduction =0.724 mg/L; LC20 Adult mortality after 21 days>2.46 mg/L; LC50 Adult mortality after 21 days>2.46 mg/L; LC100 Adult mortality after 21 days>2.46 mg/L; LOEC Adult mortality after 21 days>2.46 mg/L; NOEC Adult mortality after 21 days>=2.46 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.03 mg/L