Dirt-binding particles consisting of hydrogenated castor oil beads constitute a nonirritating alternative for abrasive cleaning of recalcitrant oily skin contamination in a three-step programme of occupational skin protection

Summary Background In occupational fields with exposure to grease, oil, metal particles, coal, black lead or soot, cleansing formulations containing abrasive bodies (e.g. refined walnut shell, corn, wood, plastic or pumice) are used. These may constitute an irritant per se. As an alternative, hydrogenated castor oil (also known as castor wax) beads have been developed as dirt‐binding particles. A polar surface contributes to their mechanical cleaning effects in removal of oily grime. Objectives Standardized examination of the in vivo effects upon the skin barrier of castor wax beads in comparison with abrasive bodies and pure detergent. Methods Three cleansing preparations – (i) detergent, (ii) detergent containing castor wax beads, (iii) detergent containing walnut shell powder – were each repetitively applied in vivo (four times daily for 3 weeks), mimicking workplace conditions, in 30 healthy volunteers (15 with and 15 without an atopic skin diathesis) and compared vs. (iv) no treatment. The treatment effects upon the skin barrier were monitored by repeated measurements of functional parameters [transepidermal water loss (TEWL), redness] and surface topography. Results After a 3‐week treatment, a significant global treatment effect (P