N,N-dimethylformamide

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

other: US EPA guideline 660/3-75-009

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

Dead fish were counted and removed at 1, 3, 6, 12, and 24 h after initial exposure and at a 24-h period thereafter.

Vehicle:

no

Details on test solutions:

Water was untreated Lake Superior water used at about 19.8 °C (+/- 2.3 °C). Water quality characteristics were measured using methods described by the American Public Health Association et al. (1975).

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

average weight of test fish: 0.912 ± 0.350 g;
delivered from Lake Mills Fish Hatchery.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Dead fish were counted and removed at 1, 3, 6, 12, and 24 h after initial exposure and at a 24-h period thereafter.

Hardness:

hardness: 40.4 - 56.3 mg/L as CaCO3

Test temperature:

about 19.8 °C (+/- 2.3 °C)

pH:

pH: 7.04 - 7.97

Dissolved oxygen:

dissolved oxygen: 54.3 - 88.9 %

Nominal and measured concentrations:

Exposure samples were analyzed on a DB-UV spectrophotometer at a wavelenght of 200 nm.
Several test concentrations (up to 5, where appropriate) and a control were tested.

Details on test conditions:

Groups of 10 fish were tested in glass exposure tanks (20x35x9 cm; containing 6.3L).
Fish were not fed 24 h before or during a test. Dead fish were counted and removed at 1, 3, 6, 12, and 24 h after initial exposure and at a 24-h period thereafter.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

7 100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 6700-7500 mg/L

Sublethal observations / clinical signs:

No controls died. DMF-exposed Lepomis macrochirus were stressed and showed mortality within 3 h after initial exposure, deaths continued throughout the test with all fish dead in the highest concentration at 96 h (no values given). The 96 h LC50 and its 95% confidence limits were 7100 (6700 - 7500) mg/L.

Validity criteria fulfilled:

yes

Conclusions:

LC50 (96 h) = 7100 mg/L (95 % CL: 6700-7500 mg/L).

Executive summary:

The acute toxicity of DMF towards fish (Lepomis macrochirus) was investigated according to US EPA guideline 660/3-75-009.

LC50 (96 h) = 7100 mg/L (95 % CL: 6700-7500 mg/L).

Description of key information

LC50 (96 h) = 7100 mg/L (95 % CL: 6700-7500 mg/L) for Lepomis macrochirus (US EPA Guideline 660/3-75-009, flow-through, GLP compliance not specified).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

7 100 mg/L

Additional information

Two valid experimental results are available regarding acute toxicity to fish.

In an experiment following US-EPA guideline 660/3 -75 -009, Lepromis macrochirus was used as test organism (Poirier et.al., 1986). The key value for chemical safety assessment is taken out of this study report (LC50 (96h) = 7100 mg/L).

For Leuciscus idus, a LC50 value greater than 10000 mg/L is reported (BASF AG, 1976). In this case the exposure time was 48 hours.