Use of a human skin in vitro model to investigate the influence of ‘every-day’ clothing and skin surface decontamination on the percutaneous penetration of organophosphates

Abstract

Organophosphates (OPs) are widely used in agriculture. Many studies have investigated the capability of personal protective equipment (PPE) to reduce chemical exposure; however, investigations into the protective effect of ‘every-day’ clothing are rare. The purpose of this study was to investigate the protective effect of ‘every-day’ clothing against dermal exposure and to measure early decontamination of skin following exposure to chlorpyrifos and dichlorvos.Using human skin in vitro, absorption of 14C-labelled chlorpyrifos (500ng/cm2), was shown to be significantly reduced when applied to clothed skin (cotton shirt), regardless of application vehicle (isopropanol (IPA) or propylene glycol (PG)). The majority of applied dose was retained within the clothing after 4h exposure. Significant reduction in absorption of chlorpyrifos (in PG) was seen through clothed skin when supplemented with skin decontamination at 4h, compared with clothed skin decontaminated after 24h, however, this was not observed with IPA.Absorption of dichlorvos (5μg/cm2) was greater through unclothed skin than chlorpyrifos for all vehicles (IPA, isopropyl myristate (IPM) and PG). Significant reduction in absorption was observed when decontaminating clothed skin at 30min, compared with decontamination at 24h (post-exposure) for all vehicles. Resultindicate that ‘every-day’ clothing is effective at reducing exposure to chemicals in contact with skin. Washing the skin surface immediately following removal of exposed clothing can further reduce exposure, depending on the properties of the chemical and vehicle applied.