Test No. 218: Sediment-Water Chironomid Toxicity Using Spiked Sediment
This Test Guideline is designed to assess the effects of prolonged exposure of chemicals
to the sediment-dwelling larvae of the freshwater dipteran Chironomus sp.
First instar chironomid larvae are exposed to at least five concentrations of the
test chemical in sediment - water systems. The test substance is spiked into the sediment
and first instar larvae are subsequently introduced into test beakers in which the
sediment and water concentrations have been stabilised. Chironomid emergence and development
rate is measured at the end of the test. The maximum exposure duration is 28 days
for C. riparius, C. yoshimatsui, and 65 days for C. tentans. The limit test corresponds
to one dose level of 1000 mg/kg. Larval survival and weight may also be measured after
10 days if required (using additional replicates as appropriate). The study report
should include the development time and the total number of fully emerged midges (sex
and number are recorded daily), the observation of any abnormal behaviour the number
of visible pupae that have failed to emerge and any egg masses deposition. The data
are analysed either by using a regression model in order to estimate the concentration
that would cause x % reduction in emergence or larval survival or growth, or by using
statistical hypothesis testing to determine a NOEC/LOEC.
Published on July 04, 2023Also available in: French
In series:OECD Guidelines for the Testing of Chemicals, Section 2: Effects on Biotic Systemsview more titles