Executive Summary
Human Health
The use of household laundry and cleaning products containing Alcohol Sulphates (Alkyl Sulphates, AS) can result in exposure to AS. The skin is the predominant route of exposure to AS, however exposure from oral intake and inhalation are also considered in this risk assessment. Direct skin exposure occurs mainly in hand-washed laundry, laundry pre-treatment, hand dishwashing and surface cleaning tasks and to a smaller extent also from residues in fabric after the washing cycle. Consumers may be indirectly exposed to low levels of AS via the drinking water and food due to the potential environmental presence of AS. Residues deposited on eating utensils and crockery after hand dishwashing may be another source of oral exposure. The use of spray cleaners is also a potential source of exposure to AS through inhalation of aerosols generated by the sprayer. The calculated body burden of AS taking into account all routes of exposure and using highly conservative or worst-case assumptions is 5.93 µg/kg bw/day.
Based on an extensive database, it has been shown that the toxicological properties of AS of different chain length covered in this risk assessment are qualitatively and quantitatively similar, justifying the decision to consider AS as a single category.
AS are of a low order of acute oral and dermal toxicity. AS are not genotoxic, mutagenic or carcinogenic, and there was no evidence of adverse effects on fertility, reproduction and development. AS are irritant to skin and eyes when applied neat or as a concentrated solution, however AS concentrations below 1% were essentially non-irritating to the human skin. The repeated-dose toxicity of AS was evaluated in several sub-acute, sub-chronic and chronic toxicity studies. In dermal and oral gavage studies AS caused local irritation at the site of first contact. The target organs for the systemic toxicity of AS are the liver and the kidney. The lowest NOAEL of AS was observed in a 90-day feeding study in the rat at a dose level of 61 mg/kg/day and was based on liver toxicity.
The comparison of the aggregate exposure and the systemic NOEL results in a Margin of Exposure of 10,100. Local dermal effects due to direct or indirect skin contact with AS containing solutions in hand-washed laundry, hand dishwashing or hard surface cleaning tasks are not of concern because AS is not a contact sensitiser and not expected to be irritating to the skin at in-use concentrations.
In summary, the human health risk assessment has shown that the use of AS in household laundry and cleaning detergents is safe and that consumer exposures are not of concern.
Environment
Alkyl Sulphates (AS) are a widely used class of anionic surfactants. They are used in household cleaning products, personal care products, institutional cleaners and industrial cleaning processes, and as industrial process aids in emulsion polymerisation and as additives during plastics and paint production. Uses in household cleaning products (the scope of HERA) include laundry detergents, hand dishwashing liquids, and various hard surface cleaners.
The HERA AS family encompasses commercial grades of linear-type primary alkyl sulphates in the C12 to C18 range. This assessment does not cover the AS present as a component of another major class of anionic surfactants, Alcohol Ethoxysulphates (AES). This will be covered separately, as part of the HERA AES risk assessment.
The total volume of AS surfactants used in Europe is estimated to be 102,000 tonnes/year on an active matter basis based on a survey of producers (1999). Based on a survey conducted among detergent formulator companies, and input from AS producers, the tonnage used in household detergents and cleaning products is estimated to be approximately 65,000 tonnes/year.
A large environmental data set is available for Alkyl Sulphates. On the environmental fate side, this includes standard biodegradation studies, advanced simulation studies of removal in treatment systems, and field monitoring data. On the environmental effects side, acute as well as chronic single-species data are available, as well as advanced studies in micro- and mesocosm systems.
Chemical removal in wastewater treatment plants was determined from advanced simulation test data, and to determine the ecotoxicological Predicted No Effect Concentrations, chronic ecotoxicity data were used.
Monitoring studies on sewage treatment plant effluents indicate that the exposure estimates in this assessment are likely to be conservative. In addition, mesocosm studies suggest that the effects assessment based on laboratory studies is also conservative.
By means of higher tier exposure and effects data, it could be shown that the use of Alkyl Sulphates in HERA applications (household detergents and cleaning products) poses no concern in any environmental compartment.
An additional exposure scenario was included in this risk assessment, by assuming the entire AS tonnage used in Europe is disposed of down the drain, rather than just the HERA tonnage. Using the same exposure and effects assessment approach, the absence of environmental concerns can also be demonstrated for the total tonnage.