Registration Dossier

Administrative data

biodegradation in soil: simulation testing
Data waiving:
other justification
Justification for data waiving:
Justification for type of information:
Simulation testing on soil is part of degradation studies according to Annex IX REACH.
Column 2 of Annex IX states that “Further biotic degradation testing shall be proposed by the registrant if the chemical safety assessment according to Annex I indicates the need to investigate further the degradation of the substance and its degradation products. The choice of the appropriate test(s) depends on the results of the chemical safety assessment and may include simulation testing in appropriate media (e.g. water, sediment or soil).”

Relevant physico-chemical properties of substance were tested with following results.
• Adsorption/Desorption study shows low adsorption rate to soil and sludge: log Koc (soil) < 1.3 (pH = 6.1, 25°C), log Koc (sludge) < 1.5 (pH = 6.1, 25°C)
• From results of hydrolysis study, the substance is found hydrolytically stable after preliminary test and the half-time of degradation is estimated to be more than 1 year. Therefore, no degradation products of parental substance are expected in water.

Also, use in terrestrial applications is performed with 13 % solution of substance in water. The solution of desired concentration is prepared by mixing 180 g with 1 litre of water. For 1 hectare of soil, 0,6 litres of 13 % solution is used. Calculated PEC (soil) = 0,0072 mg/kg with density of soil 2500 kg/m3 according to ECHA Guidance on information requirements and chemical safety assessment. Calculated PNEC (soil) = 0,009052 mg/kg.

Therefore, the risk characterisation ratio (RCR) of PEC (soil) to PNEC (soil) is below 1. The risks associated with terrestrial applications are well controlled. Simulation testing of degradation in soil is inappropriate as there is highly limited degradation expected of parental substance in hydrolysis study.

Data source

Materials and methods

Test guideline
according to guideline
OECD Guideline 307 (Aerobic and Anaerobic Transformation in Soil)

Test material

Constituent 1
Chemical structure
Reference substance name:
Humic acids, potassium salts
EC Number:
EC Name:
Humic acids, potassium salts
Cas Number:
Molecular formula:
Humic acids, potassium salts

Results and discussion

Transformation products:
not specified

Applicant's summary and conclusion