Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Based on the results of this study, the 3-hour EC20 and EC50 of Read Across substance 2 (RA2) to activated sludge respiration are greater than 1000 mg/L.
The test is regarded as valid since the variance between the two control samples was less than 15 % (8.2 %) and the 3 hour EC50 of the positive control 3,5-dichlorophenol was 28.5 mg/L. Both values are within the guideline-recommended range.

Key value for chemical safety assessment

EC50 for microorganisms:
1 000 mg/L
EC10 or NOEC for microorganisms:
1 000 mg/L

Additional information

The inhibitory effect of the Read Across test substance RA2 on the respiration rate of aerobic wastewater micro-organisms of activated sludge was investigated in a 3 hour respiration inhibition test according to the Commission Directive 87/302/EEC, No. L 133/118-122, dated May 05, 1988, and the OECD Guideline for Testing of Chemicals, Section 2, No. 209, adopted April 04, 1984.

 

The following nominal concentrations RA2 were tested: 10, 32, 100, 320 and 1000 mg test substance/l. Concentrations in excess of nominal 1000mg/l. were not tested. Defined aliquots of a clear colourless stock solution of RA2 were transferred into the test flasks and mixed with deionised water.

 

In addition, three controls and four different concentrations of the reference substance 3, 5-dichlorophenol in the range from 3.2 to 100 mg/l were tested in parallel.

 

Up to and including the highest concentration of nominal 1000 mg/l the test substance, RA2 had no inhibitory effect on the respiration rate of activated sludge after an incubation period of three hours. Therefore, the 4 hour EC20 and EC50 could not be quantified but are clearly higher than 1000 mg/L nominal under present conditions.

 

The 3 hour EC50 of the reference substance 3,5-dichlorophenol was calculated to be 28.5 mg/l (the 95 % confidence limits were not calculable) and is within the accepted range of 5 – 30 mg/L; thus, confirming suitability of the activated sludge.