Respiratory allergenic potential of plant-derived proteins: Understanding the relationship between exposure and potency for risk assessments

Abstract

Botanical ingredients (ingredients derived from plants) are finding increasing application in personal care products and the public perceives these ingredients to be safe. However, some proteins in botanicals have the potential to cause immediate-type (IgE-mediated) respiratory allergic reactions. Although reports of such reactions are uncommon, when they do occur, they can be severe. Experience with soap containing wheat proteins illustrated that under certain specific conditions, consumers may be affected. Establishing safe exposure levels for botanical proteins has been challenging. Industrial enzymes provide a rich reference dataset based on their historical association with allergic reactions among workers, which includes robust dose–response information. In the absence of similar data on the potency of plant proteins, a conservative default approach has historically been applied based on information derived from allergenic enzymes. In this article we review the historical default approach and dataset for setting limits for plant proteins in botanical ingredients based on analogy to industrial enzymes followed by a synthesis of literature data on allergic reactions following inhalation exposure to plant-derived proteins. The aim is to share relevant background information and display the relationship between exposure and potency as a first step in the development of a strategy for the development of an improved approach to support the risk assessment of plant-derived proteins.

Keywords:

• botanicals
• consumer products
• occupational exposure levels
• protein allergen
• respiratory sensitization type 1 allergy
• risk assessment

Acknowledgment

The authors gratefully acknowledge the useful comments of 3 anonymous reviewers selected by the editor for their helpful and constructive criticism which greatly improved the manuscript.

Declaration of interest

This review was performed during the normal course of the authors’ affiliation or employment as shown in the first page. None of the authors have participated in legal or regulatory proceedings during the past 5 years on the subject matter of the paper. The authors have sole responsibility for the writing and content of the manuscript.