Characterization of Dermal Exposure as a Result of Glove Penetration

Dermal exposure is a primary route of occupational chemical exposure. Contact dermatitis, a highly prevalent health outcome associated with dermal exposure, is one of the most common occupational illnesses and affects millions of workers each year. Chemically resistant gloves are the primary control method used to protect against dermal exposure. Glove assessment focuses on laboratory-based studies of chemical permeation, and these data are used to select gloves that have long break-through times for the chemical of concern. There, are however, alternative mechanisms of glove failure that can lead to dermal exposure. A study of dermal exposure to the hands resulting from glove penetration was carried out using an experimental simulation approach with two different glove types (short-cuff and long-cuff nitrile gloves). Simulations consisted of 20 participants using gloves to wash glassware in a tub of fluorescein solution. The first 10 participants used a solution with 20 PPM fluorescein and the second 10 participants used a solution with 100 PPM fluorescein. After each simulation, participants' hands were photographed under black light to measure the surface area of contamination and the fluorescein was eluted from the hands to measure the mass of fluorescein contamination. A paired t-test was used to compare of the measures of contamination for the left and right hands, but no statistically significant difference was found. As a result, left- and right-hand contamination measurements were then combined to define measures of total dermal exposure (i.e. total mass and total surface area of dermal contamination). A correlation test was run to determine the relationship between mass and surface area of contamination, descriptive statistics were computed to compare total dermal exposure by glove type and by low and high fluorescein. A paired t-test was used to compare the measures of contamination for the short-cuff and long-cuff gloves. Results indicated no statistically significant difference in measures of dermal exposure between long-cuff and short-cuff glove types. Long-cuff gloves did have more variability in dermal exposure compared to short-cuff gloves, which could be due to the extended cuff creating a sense of security and influencing a more vigorous washing behavior compared to the short-cuff simulations. This study demonstrates that fluorescein will penetrate gloves within 10 minutes of dishwashing activity, and that gloves selected based on permeation time do not offer complete protection. This is consistent with previous studies of the effects of repetitive hand movement on glove penetration and permeation. These findings affirm that PPE is an imperfect control method and that dermal exposure to the hands does occur via glove penetration. Glove selection must consider both glove penetration and permeation exposure pathways in order to effectively protect worker health and safety.