The toxicology and immunology of detergent enzymes

Enzymes and sensitization via skin exposure: A critical analysis

Some proteins, including enzymes, can induce allergic sensitization of various types, including allergic sensitization of the respiratory tract. There is now an increased understanding of the role that the skin plays in the development of IgE-mediated allergy and this prompts the question whether topical exposure to enzymes used widely in consumer cleaning products could result in allergic sensitization. Here, the evidence that proteins can interact with the skin immune system and the way they do so is reviewed, together with a consideration of the experience gained over decades of the use of enzymes in laundry and cleaning products. The conclusion drawn is that although transcutaneous sensitization to proteins can occur (typically through compromised skin) resulting in IgE antibody-mediated allergy, in practice such skin contact with enzymes used in laundry and cleaning products does not appear to pose a significant risk of allergic disease. Further, the evidence summarized in this publication support the view that proteins do not pose a risk of allergic contact dermatitis.

Enzymes in cleaning products: an overview of toxicological properties and risk assessment/management

Enzymes used in cleaning products have an excellent safety profile, with little ability to cause adverse responses in humans. For acute toxicity, genotoxicity, sub-acute and repeated dose toxicity, enzymes are unremarkable. Reproductive toxicity and carcinogenicity are also not endpoints of concern. Exceptions are the ability of some proteases to produce irritating effects at high concentrations and more importantly, the intrinsic potential of these bacterial/fungal proteins to act as respiratory sensitizers. It is a reasonable assumption that the majority of enzyme proteins possess this hazard. However, methods for characterising the respiratory sensitisation hazard of enzymes are lacking and the information required for risk assessment and risk management, although sufficient, remains limited. Previously, most data was generated in animal models and in in vitro immunoassays that assess immunological cross-reactivity. Nevertheless, by the establishment of strict limits on airborne exposure (based on a defined minimal effect limit of 60ng active enzyme protein/m(3)) and air and health monitoring, occupational safety can be assured. Similarly, by ensuring that airborne exposure is kept similarly low, coupled with knowledge of the fate of these enzymes on skin and fabrics, it has proven possible to establish a long history of safe consumer use of enzyme containing products.