Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

EC50 = 165 mg/L, 48h (Bringmann)

IC50 = 1380 mg/L, 48h (Hermens)

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
165 mg/L

Additional information

The plausibility of the available experimental data for aquatic invertebrates was tested by the use of two QSARs (unvalidated) developed for chemicals with narcotic modes of action (Van Leeuwen et al, Env. Tox. Chem., 1992, 11, 267 - 282). The following equations were selected for Daphnia Magna: Log(NOEC) = a(logKow)+b where a=-1.04, b=-1.70 and Log(EC50,48h) = a(logKow)+b where a = -0.95, b = -1.19; the standard errors were 0.25 and 0.21 log units, respectively. The LogKow for diethyl ether is within the range of the training set for both the QSARs. The predictions were as follows: EC50 = 481 mg/L (296 - 781 mg/L), NOEC = 119 mg/L (67 - 213 mg/L).

The IC50 determined by Hermens (1984) is an order of magnitude higher than that of Bringmann (1982), and in addition well above the expected uncertainty for the "EC50 QSAR". As a result, the study by Hermens is not considered to be reliable. The EC50 from Bringmann is below the expected uncertainty range for the "EC50 QSAR". However, it is still above the QSAR predicted NOEC, and is considered conservative and plausible.

The EC50 determined by Bringmann is considered to be adequate and conclusive for the purpose of risk assessment and classification and labelling, and is the value carried forward.