A review of dietary exposure and toxicological information on epoxidised soybean oil (ESBO) in food-contact applications

ABSTRACT

Plasticisers have a long history of use in the industrial manufacture and processing of polymers for the purpose of increasing the flexibility and strength of the material. Approximately, 80–90% of the plasticiser market is devoted to the production of PVC, a highly versatile thermoplastic used to produce both rigid and flexible articles. Many types of plasticisers, including ortho-phthalate esters (OPE), can be added to PVC to impart flexibility. Recently, alternatives to OPEs, such as epoxy esters and aliphatic adipates, are becoming more prevalent for use in PVC-based food-contact articles. Epoxidised soybean oil (ESBO) is used as a plasticiser in flexible PVC for many food-contact articles, including food packaging and food processing equipment, from which it can potentially migrate into food and become a component of an individual’s daily diet. The purpose of this review is to provide an update on the US dietary exposure and toxicological information on ESBO used in PVC-based food-contact articles. The cumulative dietary concentration (CDC) and cumulative estimated daily intake (CEDI) for ESBO from its use as a plasticiser in PVC-based food-contact articles (i.e. gaskets for glass jar lids and film wraps) was calculated to be 2.6 mg/kg (i.e. ppm) and 0.13 mg/kg bw/d, respectively, for the general population. Some regulatory agencies have reported safety levels for ESBO, and the most conservative no observed adverse effect level (NOAEL) was identified to be 100 mg/kg bw/d (i.e. 2000 ppm) based on a two-year feeding study in rats. The current CEDI is well below these levels, supporting the safe use of ESBO in food-contact applications.

KEYWORDS:

• ESBO
• food contact materials
• PVC
• dietary exposure
• review

Acknowledgments

We thank Drs. Jason Aungst, Raymond Brinas, and Sharon Koh-Fallet for their helpful insight during the preparation of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. The MAFF Surveillance report data was later published by Castle and co-workers (Food Additives and Contaminants, 1990, (7)1, 29–36). These results are discussed below.

2. The amount of the substance required to kill 50% of the test population.