Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

There are no experimental data available for 2,2-dimethylbutane therefore Petrotox (v3.06) has been used to estimate aquatic toxicity. Experimental data is available for n‑hexane and iso‑hexane. This data is used for read-across to 2,2 -dimethylbutane.

 

The Petrotox computer model (v. 3.06), which combines a partitioning model used to calculate the aqueous concentration of hydrocarbon components as a function of substance loading with the Target Lipid Model used to calculate acute and chronic toxicity of non-polar narcotic chemicals. Petrotox computes toxicity based on the summation of the aqueous-phase concentrations of hydrocarbon block(s) that represent a hydrocarbon substance and membrane-water partitioning coefficients (KMW) that describe the partitioning of the hydrocarbons between the water and organism.

 

Short-term toxicity to fish:

A QSAR prediction using Petrotox v3.06 predicted an acute LL50 for fish of 2.12 mg/l, which is considered the key value for acute fish toxicity.

 

This is supported by and experimental study on the read-across substance n-hexane which reported an LC50 for acute toxicity in fish of >1000 mg/l. 

 

Short-term toxicity to aquatic invertebrates:

A QSAR prediction using Petrotox v3.06 predicted an acute LL50 for invertebrates of 3.68 mg/l, which is considered the key value for acute invertebrate toxicity.

 

This is supported by and experimental study on the read-across substance n-hexane which reported a 48-hr LC50 for daphnia of 45 mmol/m3 (WAF).

 

Toxicity to aquatic algae and cyanobacteria:

A QSAR prediction using Petrotox v3.06 predicted an acute LL50 for algae of 1.56 mg/l, which is considered the key value for algae toxicity.

This is supported by two experimental studies on the read-across substance n-hexane which reported an ErL50 of 55 mg/L, EbL50 of 26 mg/L and a NOEL of 30 mg/L based on growth rate in one study and an EC50of 2.66% v/v of test substance. 

Toxicity to microorganisms:

A QSAR prediction using Petrotox v3.06 predicted an acute LL50 for algae of 8.12 mg/l, which is considered the key value for toxicity to microorganisms.

There are no experimental studies available for any of the read-across substances.

Additional information