Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The Persulfate Category includes molecules with similar chemical structure and similar physico-chemical properties. Persulfates are inorganic compounds which differ only by the cationic part of the salt. The cationic part is not expected to influence the hazardous properties of the molecule. The anionic part is identical and, therefore, the three salts are expected to display the same environmental, ecotoxicological and toxicological behaviour.

Sources of environmental exposure

Releases of persulfates into the environment are expected to be low. In manufacturing processes risk minimization methods are installed to prevent persulfate discharges. Persulfate waste (solids or solutions) will be treated to decompose the material into innocuous metal sulfates or diluted to non hazardous levels. Practically, release to the environment is limited to consumer uses. Used product containers and residual persulfate solutions (waste) will either be diluted and sent to a wastewater treatment facility or sent into a domestic waste system. Under these conditions the product is expected to be dilute and to rapidly degrade into sulfate or bisulfate salts ubiquitous to the environment. Large quantities of persulfate waste materials are usually collected in appropriate containers and disposed of as hazardous waste.

Stability in water

Substances of the Persulfate Category are soluble in water and their vapour pressures are negligible. Upon contact with water or water vapour substances of the Persulfate Category hydrolyse into cation and persulfate anion. Hydrolysis is pH and temperature dependent. Decomposition rates increase with decreasing pH and increasing temperature. The persulfate anion, independent of the cation, undergoes further decomposition in normal water or acid conditions, readily oxidizing water to oxygen, producing sulphate and hydrogen ions. All final persulfate degradation products are ubiquitous to the environment. Hydrolysis is metal catalyzed, and rapid reactions with organic is also possible.

Biodegradation

Biodegradation is not applicable to substances of the Persulfate Category, as the substances are inorganic. Upon contact with water or water vapour substances of the Persulfate Category hydrolyse into cation and persulfate anion. Hydrolysis is pH and temperature dependent. Decomposition rates increase with decreasing pH and increasing temperature. The persulfate anion, independent of the cation, undergoes further decomposition in normal water or acid conditions, readily oxidizing water to oxygen, producing sulphate and hydrogen ions. All final persulfate degradation products are ubiquitous to the environment. Hydrolysis is metal catalyzed, and rapid reaction with organic matter is also possible.

Bioaccumulation

Persulfates are very soluble in water and are not expected to bioaccumulate in soil or aqueous solutions. Upon contact with water or water vapour substances of the Persulfate Category hydrolyse into cation and persulfate anion. Hydrolysis is pH and temperature dependent. Decomposition rates increase with decreasing pH and increasing temperature. The persulfate anion, independent of the cation, undergoes further decomposition in normal water or acid conditions, readily oxidizing water to oxygen, producing sulphate and hydrogen ions. All final persulfate degradation products are ubiquitous to the environment. Hydrolysis is metal catalyzed, and rapid reactions with organic is also possible. Experimental determination of a log Pow was waived, instead a default log Pow of -1 was assumed for risk assessment (EUSES v 2.1 default). Based on the low potential for bioaccumulation, experimental determination of the bioaccumulation factor (BCF) was waived.

Transport between environmental compartments

Substances of the Persulfate Category are inorganic salts sharing the same persulfate anion moiety. Performance of a test for adsorption/desorption was waived, based on physical chemical properties and hydrolysis behaviour. Persulfates are soluble in water and their vapour pressures are negligible. Thus, persulfates released into the environment are distributed into the water compartment in the ionic form of the cation and persulfate ion. The persulfate anion readily oxydises water to oxygen producing sulphate and hydrogen ions. Persulfates are not expected to sorb to soil due to their dissociation properties, instability (hydrolysis) and high water solubility. All persulfate degradation products are ubiquitous to the environment.