2-methylpentane-1,5-diamine

Short-term toxicity to aquatic invertebrates

Description of key information

The lowest reliable 48 h EC50 for daphnids was 19.8 mg/L. However, a further reliable 48 h EC50 of 50 mg/L is reported and a supporting study reports an EC50 (48 h) between these both extreme values of 27 mg/L. For this reason a geometric mean of the two Key studies is used to generate an EC50.

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:

31.5 mg/L

Additional information

Two reliable acute toxicity studies for the category member HMD with Daphnia magna are available. pH-values of both studies were in the range recommended by OECD 202. Both are considered as reliability category 2 despite the lack of chemical analysis as the substance would be relatively stable in an aqueous solution within a period of 48 hours.

The 48h-EC₅₀ of 19.8 mg/L reported for HMD in the study performed by Stahl & Wetzel (1985, No. 303-85) is lower than the EC₅₀(48 h, Daphnia magna) of 50 mg/L determined for the same substance by Ziegenfuss & Adams (1984, No. ESC-EAG-84-8). There are no obvious reasons to prefer either of these studies. On the other hand, an EC₅₀(48 h) of 27 mg/L from a supporting study is available (performed by MITI Japan, 2002, not assignable due to missing documentation). This latter result corroborates the recommendation of REACH guidance on Information Requirements and Chemical Safety Assessment, part R.10 to take the geometric mean from both EC₅₀-values of the two reliable studies. The EC50 aquatic invertebrates for the amine heads category is therefore based on the geometric mean of the two valid studies, resulting in 31.5 mg/L.