Registration Dossier
Registration Dossier
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EC number: 231-197-3 | CAS number: 7446-11-9
Ecotoxicological Summary
Administrative data
Hazard for aquatic organisms
Freshwater
- Hazard assessment conclusion:
- no hazard identified
Marine water
- Hazard assessment conclusion:
- no hazard identified
STP
- Hazard assessment conclusion:
- no hazard identified
Sediment (freshwater)
- Hazard assessment conclusion:
- no hazard identified
Sediment (marine water)
- Hazard assessment conclusion:
- no hazard identified
Hazard for air
Air
- Hazard assessment conclusion:
- no hazard identified
Hazard for terrestrial organisms
Soil
- Hazard assessment conclusion:
- no hazard identified
Hazard for predators
Secondary poisoning
- Hazard assessment conclusion:
- no potential for bioaccumulation
Additional information
Sulphur trioxide reacts rapidly with water to form sulphuric acid, to the extent that it will react with water vapour in the atmosphere to form fumes of sulphuric acid. Sulphur trioxide is unlikely to exist in the environment except for very short periods when it may be present in air as a gas. On this basis, the hazard profile of sulphur trioxide is comparable to that of sulphuric acid with respect to environmental endpoints.
Sulphuric acid is a strong mineral acid that dissociates readily in water to hydrogen ions and sulphate ions (at environmentally relevant pH) totally dissociates and and is totally miscible with water. The hydrogen ions, although not degraded as such due to their elemental nature, contribute to the pH of the local environment. The sulphate ions are incorporated into the various mineral species present in the environment. The total dissociation of sulphuric acid at environmental pH implies that it will not, per se, adsorb onto particulates or accumulate in living tissues.
Conclusion on classification
Not relevant: no environmental exposure is predicted due to the reactivity of sulphur trioxide with water.
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