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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

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Endpoint:
toxicity to soil macroorganisms except arthropods: long-term
Data waiving:
other justification
Justification for data waiving:
the study does not need to be conducted because direct and indirect exposure of the soil compartment is unlikely
Justification for type of information:
JUSTIFICATION FOR DATA WAIVING
In accordance with column 2 of REACH Annex X, a long-term toxicity study to invertebrates is not required since direct and indirect exposure of the soil compartment is unlikely. Two routes of entry to the soil compartment are possible: via deposition of chlorite present in aerosols from cooling towers or via deposition of sewage sludge. Chlorine dioxide is fairly unstable and rapidly dissociates, predominantly into chlorite and chloride, and to a lesser extent, chlorate. There is a ready interconversion among these species in contact with water. The substance chlorine dioxide is highly reactive and it will readily react with organic matter and microorganisms present in sewage sludge or in soil and will be reduced to chloride via the transient intermediate chlorite. With regards to exposure via sewage sludge, the vast quantity of organic matter and metal ions dissolved in the aqueous phase in the STP would ensure the complete conversion of chlorine dioxide to chloride via the transient intermediate chlorite. Hence there will be no exposure to soil via sewage sludge. Chlorite in aerosols deposited in soil would also be expected to degrade to chloride on contact with soil. Therefore, a long-term toxicity test in earthworms is unjustified on the basis of no exposure.
Endpoint:
toxicity to soil macroorganisms except arthropods: short-term
Data waiving:
other justification
Justification for data waiving:
the study does not need to be conducted because direct and indirect exposure of the soil compartment is unlikely
Justification for type of information:
JUSTIFICATION FOR DATA WAIVING
In accordance with column 2 of REACH Annex X, a short-term toxicity study to invertebrates is not required since direct and indirect exposure of the soil compartment is unlikely. Two routes of entry to the soil compartment are possible: via deposition of chlorite present in aerosols from cooling towers or via deposition of sewage sludge. Chlorine dioxide is fairly unstable and rapidly dissociates, predominantly into chlorite and chloride, and to a lesser extent, chlorate. There is a ready interconversion among these species in contact with water. The substance chlorine dioxide is highly reactive and it will readily react with organic matter and microorganisms present in sewage sludge or in soil and will be reduced to chloride via the transient intermediate chlorite. With regards to exposure via sewage sludge, the vast quantity of organic matter and metal ions dissolved in the aqueous phase in the STP would ensure the complete conversion of chlorine dioxide to chloride via the transient intermediate chlorite. Hence there will be no exposure to soil via sewage sludge. Chlorite in aerosols deposited in soil would also be expected to degrade to chloride on contact with soil. Therefore, a long-term toxicity test in earthworms is unjustified on the basis of no exposure.

Description of key information

Data waiving: In accordance with column 2 of REACH Annex IX, a short-term toxicity study to invertebrates is not required since direct and indirect exposure of the soil compartment is unlikely.

 Data waiving: In accordance with column 2 of REACH Annex X, a long-term toxicity study to invertebrates is not required since direct and indirect exposure of the soil compartment is unlikely.

Key value for chemical safety assessment

Additional information

Two routes of entry to the soil compartment are possible: via deposition of chlorite present in aerosols from cooling towers or via deposition of sewage sludge. Chlorine dioxide is fairly unstable and rapidly dissociates, predominantly into chlorite and chloride, and to a lesser extent, chlorate. There is a ready interconversion among these species in contact with water. The substance, chlorine dioxide is highly reactive and it will readily react with organic matter and microorganisms present in sewage sludge or in soil and will be reduced to chloride via the transient intermediate chlorite. With regards to exposure via sewage sludge, the vast quantity of organic matter and metal ions dissolved in the aqueous phase in the STP would ensure the complete conversion of chlorine dioxide to chloride via the transient intermediate chlorite. Hence there will be no exposure to soil via sewage sludge. Chlorite in aerosols deposited in soil would also be expected to degrade to chloride on contact with soil. Therefore, a short-term toxicity test and a long-term toxicity test in earthworms are unjustified on the basis of no exposure.