Cyclohex-1,2-ylenediamine

Toxicity to microorganisms

Description of key information

One reliable study on Pseudomonas putida growth inhibition is available for the amine heads category taking into account the caustic properties of the category. 

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

12 500 mg/L

Additional information

Only one reliable (reliability category 2) study report is available for the amine heads category taking into account the caustic properties of its members (Siebel-Sauer, 1992, No. 00001-3/84). In a Pseudomonas putida growth inhibition test bacterial suspensions were exposed to increasing concentrations of category member HMD for 20 hours with and without pH neutralization. The bacterial density was measured by optical densitometry at different time intervals in four replicates. EC₁₀(20 h) of pH-neutralized test solutions was calculated as 12500 mg/L, while the corresponding value determined from solutions not pH-adjusted was reported as 37.5 mg/L, demonstrating the importance of pH-correction.

Further not reliable studies (reliability category 3) are available for category members DCH and MPMD. In both studies pH was not adjusted and no EC_x-values are reported. From the original data however, an EC₁₀(18 h) for DCH of around 125 mg/L and an EC₂₀(18 h) for MPMD around 30 mg/L could roughly be estimated. As DCH is the least caustic member of the amine heads category, the observed effect concentrations without pH-adjustment fit very well to the physicochemical properties of the members.