Benzyldimethylamine

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:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

not specified

Analytical monitoring:

yes

Test organisms (species):

Pimephales promelas

Details on test organisms:

age: 29 days
mean length: 22.3 mm
SD length: 1.372 mm
mean weight: 0.155 g
SD weight: 0.0268 g
loading: 1.550 g/L

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

36.5 mg/L CaCO3 (3.85)

Test temperature:

25.4 °C (0.32)

pH:

7.61 (0.10)

Dissolved oxygen:

6.6 (mg/L) (0.33)

Nominal and measured concentrations:

Nominal concentrations: 14.2 mg/L, 21.8 mg/L, 33.6 mg/L, 51.7 mg/L and 79.5 mg/L
Average concentrations: 15.7 mg/L, 22 mg/L, 30.6 mg/L, 46.6 mg/L and 67.6 mg/L

Details on test conditions:

alkalinity: 40 mg/L CaCO3 (0.71)
tank volume: 2.0 L
toxicant stock: 2200 mg/L diluted (blended)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

37.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Sublethal observations / clinical signs:

Affected fish lost schooling behavior, swam near the tank surface, and were overreactive to external stimuli. Equilibrium loss was not observed prior to death. Effect data were not reccorded. The pH of the stock solution was adjusted to that of lake water with HCl.

Conclusions:

A LC50 of 37.8 mg/L in 96 hours was determined in a test with Fathead Minnow in the presence for benzyldimethylamine (Geiger, 1986).

Executive summary:

In a 96-h acute toxicity study, Fathead Minnow (Pimephales promelas) were exposed to benzyldimethylamine at nominal concentrations of 14.2 mg/L, 21.8 mg/L, 33.6 mg/L, 51.7 mg/L and 79.5 mg/L under static conditions. The 96-h LC50 was 37.8 mg/L, based on mortality. Affected fish lost schooling behavior, swam near the tank surface, and were overreactive to external stimuli. Equilibrium loss was not observed prior to death. The pH of the stock solution was adjusted to that of lake water with HCl.

Description of key information

A LC50 of 37.8 mg/L in 96 hours was determined in a test with Fathead Minnow in the presence for benzyldimethylamine (Geiger, 1986). This value is further supported by additional short therm toxicity to fish studies.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

37.8 mg/L

Additional information

Key study:

In a 96-h acute toxicity study, Fathead Minnow (Pimephales promelas) were exposed to benzyldimethylamine at nominal concentrations of 14.2 mg/L, 21.8 mg/L, 33.6 mg/L, 51.7 mg/L and 79.5 mg/L under static conditions. The 96-h LC50 was 37.8 mg/L, based on mortality. Affected fish lost schooling behavior, swam near the tank surface, and were overreactive to external stimuli. Equilibrium loss was not observed prior to death. The pH of the stock solution was adjusted to that of lake water with HCl (Geiger, 1986).

Supporting studies:

- In a supporting study (BASF, 1987) golden orfe were tested in a static freshwater test. In non pH adjusted water a LC0 of 10 mg/L and a LC100 of 46.4 mg/L were measured, whereas in adjusted water also a LC0 of 10 mg/L and a LC100 of > 100 mg/L was noted. In both cases no exact LC50 was derived. This study shows that the toxic effects are mainly attributed to the change of pH. The values with adjusted pH strongly support the findings of the key study.

- In a static freshwater test by Bayer (1979) with Leuciscus idus only a LC0 of 20 mg/L could be detected. No information about pH adjustment was given.

- In a 48 h semistatic freshwater test with Oryzias latipes (MITI, 1992) an LC50 of 59.3 mg/L. No information about pH adjustment was given.

Conclusion:

The LC50 value of 37.8 mg/L determined in the key study is further strengthened by the findings in the supporting studies. Lower values found in the study by BASF (1987) are due to non adjusted pH. With an adjusted pH the study by BASF (1987) is in line with the key study, where also an adjustement of the pH was done.