Industrial microbial enzyme safety: What does the weight-of-evidence indicate?

Abstract

With the exception for the potential skin and eye irritating effects of some proteases, and the well-documented potential for respiratory sensitization in case of work place exposure, enzymes in general don't produce acute toxicity, dermal sensitization; genotoxicity, or repeated dose oral toxicity. Acute inhalation, reproduction, chronic toxicity, and carcinogenicity are not relevant for enzymes. Several hundred mutagenicity studies have been conducted on bacterial and mammalian cells using a variety of enzymes. No positive findings were observed. > 225 90-day studies have been performed and submitted to EFSA with no adverse findings, including in the bone marrow. The data showing no adverse effects for enzyme preparations also confirms that microbial metabolites and fermentation materials lack toxicity as well. Exposure to enzyme products is also minimal as recommended use levels are low, generally <0.1% (wt/wt). The weight-of-evidence indicates that there are no concerns for oral toxicity of enzymes in general, nor genotoxicity. Therefore, the continued routine practice of performing genotoxicity and 90-day studies on enzyme preparations as part of approval requirements is questionable, and establishing general health-based guidance values for enzymes may be considered. A criterion for our assertion that general health-based guidance values be established is to select and use suitable non-toxigenic microbial production strains, per decision tree guidelines.