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Alkyl sulfates are commonly used as an anionic surfactant in detergents to clean wool, liquid soaps, surface cleaners, as active ingredients in laundry detergents, shampoos and conditioners. They can also be found in other household products such as toothpastes, antacids, cosmetics and foods. Generally they are found in consumer products at concentrations ranging from 3-20%. In 2003 approximately 118,000 t/a of alkyl sulfates were used in the U.S.

Alkyl sulfates consist of a hydrophobic hydrocarbon chain, a polar sulfate or sulfonate group (containing an anion) and either a cation or amine to neutralize the sulfate group. Examples include: sulfuric acid mono dodecyl ester sodium salt, potassium dodecyl sulfide, and sulfuric acid mono dodecyl ester ammonium salt.

They can be produced through alcohols in petrochemical or oleochemical feedstock (consisting of animal or vegetable oils and fats), using the Zeigler process, or through oxo synthesis. If produced from oleochemical feedstock or the Zeigler process, the hydrocarbon chain will be linear. If derived using the oxo process, a low level of branching will appear usually with a methyl or ethyl group at the C-2 position, containing even and odd amounts of alkyl chains.

Human Health
Alkyl sulfates if ingested are well absorbed and are metabolized into a C3, C4 or C5 sulfate and an additional metabolite. The highest irritant of the alkyl sulfates is C12ASO4Na with the threshold before irritation at a concentration of 20%. Surfactants in consumer products are typically mixed reducing likelihood of irritation. According to OECD TG 406, alkyl sulfates in animal studies were not found to be skin sensitizers.

The No Observed Adverse Effect Level in laboratory studies, was found to be 400 mg a.i./kg bw/day in mice. Liver toxicity was seen after repeated oral treatments with chain lengths C12 to C18 causing an increase in organ weight, enlargement of cells and elevated liver enzymes.

Laboratory studies have not found alkyl sulfates to be genotoxic, mutagenic or carcinogenic. No long term reproductive effects have been found.

Environment
Alkyl sulfates biodegrade easily, even starting likely before reaching the wastewater treatment plant (WWTP). Once at the plant, they are rapidly removed by biodegradation. Invertebrates were found to be the most sensitive trophic group to alkyl sulfates, with C14 length most toxic. C12ASO4Na tested on Uronema parduczi, a protozoan, was found to have the lowest effect value with the 20 h-EC5 being 0.75 mg/l. Chronic exposure tests with C12 to C18 with the invertebrate Ceriodaphnia dubia found the highest toxicity is with C14 (NOEC was 0.045mg/l).

Limited information is available regarding experimental tests on benthos in a water-sediment system (although no significant risk is expected due to a partitioning coefficient Kd <350) or for terrestrial organisms (although literature suggests only toxic for soil organisms at high levels).

Alkyl sulfates degrade before reaching their boiling point due to low vapor pressure (for C8-18 from 10-11 to 10-15 hPa). Soil sorption is proportional to carbon chain length, with a length of 14 and more having the highest sorption rate. Soil concentrations have been found to vary from 0.0035 to 0.21 mg/kg dw.

Exposure
The primary disposal of Alkyl sulfate from used commercial products is wastewater. The concentration in effluent from WWTPs has been measured at 10ug/l and lower.