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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Sediment toxicity

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
sediment toxicity: short-term
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 235 (Chironomus sp., Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes
Specific details on test material used for the study:
Methomyl technical
DPX-X1179-571
Purity: 99.4%
Analytical monitoring:
yes
Vehicle:
yes
Remarks:
water
Test organisms (species):
Chironomus dilutus (previous name: Chironomus tentans)
Study type:
laboratory study
Test type:
static
Water media type:
freshwater
Type of sediment:
natural sediment
Remarks:
silica sand (US Silica, Berkeley Springs, West Virginia)
Limit test:
no
Duration:
48 h
Hardness:
140 -144 mg/L as CaCO3
Test temperature:
22.5-23.5°C
pH:
7.1-8.4
Dissolved oxygen:
8.1 - 8.4 mg/L
Conductivity:
318 - 332 μS/cm
Nominal and measured concentrations:
Nominal: 0, 0.75, 1.5, 3.0, 6.0, 12 mg/L
Measured: 0, 0.76, 1.5, 3.1, 6.1, and 12 mg/L
Reference substance (positive control):
no
Key result
Duration:
48 h
Dose descriptor:
LC50
Effect conc.:
5.4 mg/L
Nominal / measured:
meas. (not specified)
Basis for effect:
mortality
Key result
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
0.76 mg/L
Nominal / measured:
meas. (not specified)
Basis for effect:
mortality
Reported statistics and error estimates:
48-hr LC50 = 5.4 mg/L with 95% confidence limits of 3.9 -8.2 mg/L
Validity criteria fulfilled:
yes
Conclusions:
48-hour LC50 = 5.4 mg/L with 95% confidence limits of 3.9 and 8.2 mg/L
Executive summary:

The objective of this study was to determine the acute effects of methomyl on the midge (Chironomus dilutus) under static test conditions for a period of 48 hours according to OECD guideline 235. Midges were exposed to a geometric series of five test concentrations, a negative control (dilution water) and a HEPES® buffer control (dilution water adjusted to pH 7) for 48 hours under static conditions. Four replicate test chambers were maintained in each treatment and control group, with five midges in each test chamber for a total of 20 midges per concentration. Nominal test concentrations selected were 0.75, 1.5, 3.0, 6.0 and 12 mg active substance/L. Measured concentrations were 0, 0.76, 1.5, 3.1, 6.1, and 12 mg/L.

 

The 48-hour LC50 value was 5.4 mg a.s./L, with 95% fiducial limits of 3.9 and 8.2 mg a.s./L. The highest mean, measured test concentration causing no mortality at test end was 0.76 mg a.s./L. The lowest mean, measured test concentration causing 100% mortality at test end was >12 mg a.s./L, the highest concentration tested.

Description of key information

Duration/Value Type Species  Value  Guideline  Reliability
48-hour LC50 midge (Chironomus dilutus)  5.4 mg/L  OECD 235  1

Key value for chemical safety assessment

Additional information