In food handling and food processing, gloves serve the dual purpose of protecting the worker and protecting the food from human pathogens such as bacteria and viruses. These gloves, however, are made from a wide range of natural and synthetic chemicals. It is important that the chemicals in the glove material do not inadvertently migrate to the food and become an unintended food additive.
In the USA, the Food and Drug Administration (FDA) regulates three classes of food additives. Direct food additives, such as food coloring, are added to and remain in the food. Secondary direct food additives are added to the food during processing, but are removed from the final food product. Indirect food additives are substances that come into contact with the food but are not intended to be added to the food. These additives could come from anything the food comes into contact with, including equipment, packaging, and gloves.
FDA 21 CFR Part 177.2600
To ensure gloves will not transfer harmful chemicals, colors, odors or tastes to food, they must comply with FDA 21 CFR Part 177.2600 – Rubber articles intended for repeated use. This Code of Federal Regulations (CFR) lists the permitted materials and chemicals that can come into contact with food. This includes the elastomers, such as acrylonitrile-butadiene copolymer (nitrile,) chloroprene polymers, and natural rubber (latex.) It also details acceptable accelerants, activators, antioxidants, plasticizers, fillers and colorants used in manufacturing these rubber articles.
The code stipulates extractable limits for both fatty and aqueous (watery) foods. Overall migration – the total of the substances that can migrate – is tested, measured and reported as milligrams per square inch.
The overall migration limit (OML) for fatty foods is 20 milligrams per square inch at 7 hours, with no more than one additional milligram between 7 and 9 hours.
The OML for aqueous foods is 175 milligrams per square inch at 7 hours, with no more than 4 milligrams per square inch between 7 and 9 hours.
Using RoyalTouch300 Nitrile Exam Gloves as an example, overall migration can be quite low compared to the requirement.
|Extraction Conditions||Overall Migration for
Glove Sample (mg/in2)
|21 CFR Part 177.2600
|Distilled water at reflux temperature for 7 hours||ND(<0.5)||20||Comply|
|Distilled water at reflux temperature for 9 hours (additional 2 hours from initial 7 hours extraction)||ND(<0.5)||1||Comply|
|n-Hexane at reflux temperature for 7 hours||0.6||175||Comply|
|n-Hexane at reflux temperature for 9 hours (additional 2 hours from initial 7 hours extraction)||ND(<0.5)||4||Comply|
With over 200 glove types on the market – considering differences in material composition, thickness, internal and external treatments, powder, and modulus – it is important to determine if your selected glove is suitable for food contact.
While most examination gloves would meet this FDA regulation, ASTM standards for exam gloves are more about barrier resistance and durability, and do not directly address overall migration of chemicals.
To help you verify that a glove complies with CFR 21, the glove company should be able to supply a FDA letter of guarantee or a document with the overall migration test results.