Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Reliable proprietary studies for 2-methylbut-2-ene on the acute freshwater toxicity of the three trophic levels (fish, Daphnia and algae) and toxicity towards micro-organisms were identified. The studies were conducted to standard guidelines and according to GLP and so are considered fully reliable for use as key studies. Algae were found to be less sensitive than either invertebrates or fish which had similar sensitivity to the test substances (EC50 3.84 mg/L and LC50 4.99 mg/L respectively). The substance was not toxic to micro-organisms at a concentration of 2.1 mg/L.

The information gathered indicates that 2-methylbut-2-ene is of low toxicity to environmental receptors. In the PBT assessment, none of the studies evaluated meet the acute LC50/EC50 toxicity (T) screening criteria of <0.1 mg/L or the chronic criteria of <0.01 mg/L for marine or freshwater organisms based on Annex XIII of the REACH Regulation. The lowest results for each trophic level are a 96 hour LC50 for fish of 4.99 mg/L, a 48 hour EC50 forDaphniaof 3.84 mg/L, a 72 hour EC50 for algae of 12.0 mg/L based on growth rate as well as a NOEC for algae of 7.22 mg/L based on growth rate. Therefore, 2-methylbut-2-ene is not considered to be T on the basis of the environmental screening criterion.