Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Data are available for the three trophic levels fish, aquatic invertebrates and algae. The most sensitive species is fish with a 96-h LC50 of 68.1 mg/L.

 

Short-term toxicity to fish

Acutely harmful to fish

The acute toxicity of 2-ethyl-4-methylimidazole (CAS 931-36-2) to fish was tested in a static test according to the national guideline German Industrial Standard DIN 38412, part 15). The test species was Leuciscus idus. The 96-h LC50 was determined to be 68.1 mg/L (nominal; BASF AG, 1990; report no. 10F0166/895233).

 

Long-term toxicity to fish

No data available.

In Annex IX of Regulation (EC) No 1907/2006, it is laid down that long-term toxicity to fish shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on fish.

According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or is assessed to be a PBT or vPvB.

2 -ethyl-4 -methylimidazole is readily biodegradable. Based on the measured log Kow of 1.13, significant bioaccumulation is not to be expected, the lowest acute toxicity value was 68.1 mg/L (fish, 96 -h LC50).

The hazard assessment of 2 -ethyl-4 -methylimidazole reveals neither a need to classify the substance as dangerous to the environment, nor is it a PBT of vPvB substance, nor are there any further indications that the substance may be hazardous to the environment.

Therefore, and for reasons of animal welfare, a long-term study on the toxicity to fish is not provided.

 

 

Short-term toxicity to aquatic invertebrates

With high probability acutely not harmful to aquatic invertebrates.

The acute toxicity of 2-ethyl-4-methylimidazole (CAS 931-36-2) to aquatic invertebrates was test in a static test according to the EU method C2 of Annex V to Directive 79/831/EEC. The test species was Daphnia magna. The test concentrations were not analytically verified but are assumed to be stable. The 48-h EC50 was determined to be 297 mg/L (nominal; BASF AG, 1990; report no. 1/0245/2/89-0245/89). It can be concluded that with high probability 2-ethyl-4-methylimidazole is acutely not harmful to aquatic invertebrates.

 

Long-term toxicity to aquatic invertebrates

No data available.

In Annex IX of Regulation (EC) No. 1907/2006, it is laid down that long-term toxicity testing on invertebrates (preferred species Daphnia) shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on aquatic invertebrates.

According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or is assessed to be a PBT or vPvB.

The hazard assessment of 2-ethyl-4-methylimidazole reveals neither a need to classify the substance as dangerous to the environment, nor is it a PBT or vPvB substance, nor are there any further indications that the substance may be hazardous to the environment.

Therefore, long-term toxicity in aquatic invertebrates is not provided.

 

Toxicity to aquatic algae and cyanobacteria

With high probability acutely not harmful to aquatic algae.

The toxicity of 2-ethyl-4-methylimidazole (CAS 931-36-2) was tested in a growth inhibition test according to the German Industrial Standard DIN 38412, Part 9. The test species was Desmodesmus subspicatus. The test item was studied in two separate assays with either pH-adjusted or not pH-adjusted test solutions. The 72-h ErC50 was determined to be 124.8 mg/L if the test solutions were not pH-adjusted (nominal; BASF AG 1990; Study no. 2/0245/89). The test item concentrations were not analytically verified, but are assumed to be stable.

 

Toxicity to microorganisms

The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriately low concentrations.

The toxicity of 2-ethyl-4-methylimidazole (CAS 931-36-2) to microorganisms was studied in a respiration inhibition test according to Annex of EEC Directive 88/302/EEC, which corresponds to OECD Guideline 209 and ISO Standard 8192. Activated sludge from a wwtp treating municipal sewage was used as the test system. The 30-min EC20 was determined to be 650 mg/L, the 30-min EC50 was > 1000 mg/L (BASF AG, 2005; report no. 08G0379/053111).