There are standardized laboratory tests for chemical protective gloves that provide estimates of breakthrough time and steady-state permeation flux. However, there is evidence to suggest that these tests may not be completely relevant to glove usage in the workplace. There is no consensus about how glove workplace effectiveness should be assessed, although a few studies have attempted to measure the effectiveness of chemical protective gloves. We have used a conceptual model of dermal exposure to help analyse how workers' skin may become exposed while wearing gloves, and propose a new glove workplace protection factor (PFgloves), which is based on the ratio of the estimated uptake of chemicals through the hands without gloves to the uptake through the hands while wearing protective gloves. Mathematical simulations demonstrate that glove protection factor is unlikely to be constant for a glove type, but will be strongly influenced by the work situation and the duration of the exposure. This has important consequences for the selection of protective gloves.