Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Short-term toxicity

Fish:

QSAR models were used to estimate LC50 values because no study with the free base was located. The ECOSAR estimate for acute toxicity to fish was LC50(96 hr)= 35 mg/L for the free base and approx. 200 mg/L for the neutral molecule. The estimate obtained with TEST was 64.3 mg/L. The former was selected as key and the latter as supporting study (GUBDH, 2012).

 

A valid GLP guideline study with the neutralized is available. The LC50(96 hr)  212 mg/L, with a very steep dose-mortality curve (10% mortality at 180 mg/L, 90% mortality at 250 mg/L). The experimental LC50(96 hr)-value is in good agreement with the ECOSAR estimate. Comparison with the estimate for the free base indicates that the latter is much more toxic, most probably as a result of the high pH-value. An increase of the pH is not to be expected at very low doses in the range of the PNEC.

 

Aquatic invertebrates:

The 48-h EC50for acute effects on aquatic invertebrates is 29.7 mg/L with the free base (EU method C2;Daphnia magna, BASF AG, 1992).

 

Algae:

The 72-h ErC50based on growth rate was 9 mg/L (free baseScenedesmus subspicatus(EU method C3, BASF AG, 1991).

 

Microorganisms:

The key study was conducted with Pseudomonas putida using a national method DIN 38412 Part 8 with a duration of 16 hours. The EC50 (16 hrs) ,based on biomass, was 480 mg/L with the free base. No growth inhibition was seen with the neutralized substance at 125 and 1000 mg/L (BASF AG, 1991).

Further, the respiration of activated industrial sludge was not affected, i.e. the oxygen was 5 to 10% increased in the presence of 400 or 800 mg DMBA/L compared to the controls (BASF AG, 1986).

 

Endpoint

Organism group

Species

Value [mg/L]

Reliability

Remarks

Source

96-h LC50

Fish

n.a.

35.0

2

key study

QSAR

ECOSAR

GUBDH (2012)

96-h LC50

Fish

Fathead minnow

64.3

2

supp. study

QSAR
TEST

GUBDH (2012)

48-h EC50

Aquatic invertebrates

Daphnia magna

29.7

1

key study

analytically verified concentrations;
semi-static

BASF AG (1992)

72-h ECr50

Aquatic algae

Desmodesmus subspicatus(reported asScenedesmus subspicatus)

9

2

Weight of Evidence

Free base; inhibition based on growth rate

BASF AG (1991)

16-h EC50

Microorganisms

Pseudomonas putida

480

2

key study

inhibition based on biomass

BASF AG (1991)

16-h NOEC

Microorganisms

Industrial activated sludge

1000

Supporting study

Parameter: respiration

BASF AG (1986)

 

N, N-dimethylbutylamine is acutely toxic to fish, aquatic invertebrates, and algae. The toxicity of the neutralize molecule is much less pronounced.

Disturbances of wastewater treatment processes are not to be expected when N, N-dimethylbutylamine is released in appropriate amounts.

 

Long-term toxicity

 

Fish:

No valid data are available for the assessment of long-term toxicity to fish.

Aquatic invertebrates:

No long-term result study is available.

 

Algae:

No long-term result is available.