Different skin irritation abilities of different qualities of sodium lauryl sulphate

Abstract

A marked variation in the concentration of sodium lauryl sulphate (SLS) used for irritant patch testing is found in the literature, but is hitherto unexplained. In the present study, 2 different qualities of SLS were tested clinically on healthy volunteers. The skin responses were evaluated by visual scoring as well as by non-invasive measurement of transepidermal water loss (TEWL), blood flow and oedema. A significant difference in the skin response to the 2 qualities was found both clinically and by non-invasive methods used for quantitation. 5 different qualities of SLS were investigated by high-performance liquid chromatography (HPLC). Marked discrepancies in the quantity of C12 carbon chains in the products were found, offering an explanation for the proven difference in the clinical response. It is concluded that only SLS qualities of high purity should be used for irritant patch testing, and that both the quality and the purity of SLS should be stated.

The Influence of Urea Treatment on Skin Susceptibility to Surfactant-Induced Irritation: A Placebo-Controlled and Randomized Study

“…It is possible that the absence of a significant increase in blood flow and only a 30% increase in TEWL during repeated exposure to SLS were too weak responses to detect significant differences between the creams on this limited number of subjects. It is possible that an increased response could have been induced by the use of another quality of SLS [14] and another type of exposure, as recommended by the Standardization Group of the European Society of Contact Dermatitis [13]. However, the concern that urea makes the skin more susceptible to toxic substances [2] and acts as a general penetration enhancer [3] could not be verified by the present data.…”

“…This quality allows a wider range of the length of the carbon chain than the analytical grade of SLS, which mainly is comprised of C 12 [14].…”

Skin cleansers for occupational use: testing the skin compatibility of different formulations

“…Of the product, 200 mg was applied to the volar forearm of 20 healthy test persons via Finn chambers (18 mm diameter). Standards were demineralised water and freshly prepared 0.5% sodium lauryl sulphate (Agner et al 1989;Lee and Maibach 1995;Sugar et al 1999) from Merck, Darmstadt, Germany (purity <99%). Application times were: 1st day, 2 h; 2nd day, 4 h; 3rd day, 6 h; 4th day, 6 h (application of a particular test product must be stopped before the end of the allotted time in the event of excessive skin reaction).…”

Induction of a Hardening Phenomenon and Quantitative Changes of Ceramides in Stratum Corneum

“…A study conducted in Germany reported that 32% of surveyed junior hairdressers experienced chronic irritant contact dermatitis (CICD) during their first year in the occupation, with repetitive exposure to the offended materials diminishing the prevalence of clinical symptoms by 90%2. This long course of diminished non-specific responses to chronic repetitive exposure is termed the hardening phenomenon or accommodation3-5. It describes the condition when ICD disappears despite continued exposure to the irritant and avoidance of CICD3-6.…”