The FDA Food Safety Modernization Act (FSMA) was introduced in 2011, aiming to prevent food contamination and subsequent foodborne illnesses rather than just respond to it. One overlooked element within the FSMA is disposable gloves. Labeled as intermittent contact items, the risk of contamination from these products is not seen as great enough to warrant close observation.
However, growing scientific evidence shows disposable gloves, in direct contact with food, can and do affect food safety, with around 15 percent of food service foodborne outbreaks implicating contaminated gloves as contributory factors in the outbreak.
What are Food Service Gloves?
Food service gloves are certified under FDA Title 21 CFR Part 177, which states that the components of the glove must comply with the FDA regulations and consist of “Substances generally recognized as safe for use in food or food packaging.”
However, the quality and safety of disposable gloves is limited to Letters of Compliance and Guarantee on the general make and model of the glove submitted (once) for testing, not necessarily the subsequent gloves produced. There are few controls required for glove manufacturing relating to the reliability of raw materials, manufacturing processes, and factory compliance after the certification has been awarded.
It is possible for a glove manufacturer to achieve FDA Title 21 CFR Part 177 certification for a glove, then alter manufacturing and hygiene practices, and use cheap raw materials to save costs. Cheap raw materials lower glove strength, flexibility, and durability—increasing glove failure rates, and may also introduce toxic compounds, including known endocrine disruptors and potassium cyanide to glove users and food products.
Fluctuations in raw material prices and the demand for lower costs from the end user puts manufacturers under pressure to sacrifice ingredient quality and substitute raw materials to meet these demands.
The opportunity also exists for deliberate or accidental contamination within the manufacturing process, which the FSMA is now addressing.
Are Food Service Gloves Food Safe?
The AQL of a disposable glove is the “Acceptable Quality Level” and refers to a quality standard for measuring pinhole defects. Glove manufacturers test a random sample of gloves from a batch during initial production. The lower the AQL, the less defects gloves have. An AQL of 1.5, for example, requires that gloves be manufactured with no more than 15 failures for every 1,000 gloves produced.
In comparison to medical or examination grade gloves, no formal government regulations or inspection program exists for food service gloves over and above the FDA Title 21 CFR Part 177 regulation. There is no AQL requirement for food service gloves, meaning there are no guidelines for maximum pinhole defects—no guidelines for the number of failures per box.
Glove Holes and Food Contamination
Moreover, the human skin is a rich environment for microbes consisting of around 1,000 species, and the skin surface can contain on average 2 million to 10 million microorganisms. Most are resident species, some with the potential to cause disease (Staphylococcus spp. or Streptococcus spp.) but transient pathogens are the driver of foodborne infection transmission.
Organisms can become resident colonizers on hands, and combined with a glove puncture, a “liquid bridge” of microbial contamination can flow to contact surfaces of food.
Studies have shown up to 18,000 staphylococci can pass through a single glove hole during a 20-minute period, even though the hands had been scrubbed for 10 minutes prior to gloving. With more than 250 different foodborne diseases associated with food or drink there is ample opportunity for leaky gloves to share responsibility for transmission.
In-use glove studies show that 50-96 percent of glove punctures go undetected by wearers, with the potential to release tens of thousands of bacteria from internal glove surfaces to food.
Chemicals that Cause Cancer
Vinyl (PVC, Polyvinyl chloride) gloves are the most commonly used glove in food handling and processing in the U.S. due to assumed price savings. Up to 50 percent of vinyl glove raw materials are made up of plasticizers which, to reduce costs, can contain inexpensive phthalates DINP (Diisononyl phthalate) and DEHP (Bis(2-ethylhexyl) phthalate), and BPA (Bisphenol A).
Phthalates have been shown to leach from products into the human body via ingestion, inhalation, and dermal absorption. Because phthalate plasticizers are not chemically bound to PVC, they can easily leach and evaporate into food, particularly fatty foods, such as butter, oils, and meat—where they become mostly soluble. Phthalate plasticizers can also be absorbed through worker’s skin and quickly contaminate food products.
Exposure to DEHP has been associated with adverse reproductive, neurobehavioral, and respiratory outcomes in children and metabolic disease risk factors, such as insulin resistance in adolescents and adults.
Both DiNP and DEHP have been found to adversely impact human health and have been added to the Californian Proposition 65 list of chemicals known to the state of California to cause cancer.
Studies conducted in Japan found that use of disposable PVC gloves during the preparation and packaging of meals was a major source of dietary intake of DEHP. The same study also demonstrated a decline in DEHP levels in prepared meals after the ban of DEHP in PVC gloves in Japan.
Food is likely contaminated with phthalates and BPA during processing from PVC in materials such as PVC (vinyl) gloves and food packaging materials.
In 2001, Japan banned PVC gloves for food handling due to the well-documented adverse effects on health. The European Union (2008) has banned the use of DEHP in food service gloves out of concern that the chemical will leach into food and be ingested.
Adverse health effects of exposure to BPA and phthalates in U.S. food and occupational settings is estimated to result in $175 billion in healthcare costs.
Vinyl Gloves and Cross-Contamination
Gloves have the potential to mitigate, transfer, or amplify cross-contamination risks.
There is a growing accumulation of scientific evidence showing vinyl gloves (over other types) are responsible for a majority of cross-contamination events in food handling related to glove use where glove type is identified.
Due to their polymeric structure, numerous studies have shown vinyl gloves have an increased permeability to bacteria and virus, and in some cases, begin leaking as soon as they are donned, increasing the risk of cross-contamination for both the glove users and the food they are handling.
Recent independent research conducted by international scientific consultant on food safety and glove expert Barry Michaels has also shown that the risk of cross-contamination via vinyl gloves when used in food handling is significant when compared to nitrile gloves.
The science involved in cross-contamination is complex, involving the physical chemistry of surfaces, soils, and pathogens. Liquid and soil transfer to and from surfaces is controlled by forces of attraction governed by the surface tension of liquids (or semi-solids) and the surface free energy of surfaces.
The surfaces of polyvinyl chloride (vinyl) gloves are more energetic than nitrile gloves, with pick-up and spread thermodynamically favored. This means that food and human soil contaminants are more easily picked-up and spread over vinyl glove surfaces and anything they touch when compared to lower-stick nitrile gloves.
Published studies by independent investigators confirm that glove material and glove hydrophobicity were the most important factors influencing bacterial transfer from a contaminated surface to a gloved hand—more hydrophilic vinyl gloves favor transfer while the more hydrophobic nitrile gloves have reduced risk.
From a food safety point of view, because food worker’s gloves are in direct contact with food, cross-contamination will follow the path of least resistance, in this case favoring vinyl glove pickup and transfer. Protecting food from bacterial and viral transfer from a gloved hand is essential for food and consumer safety to reduce foodborne illness and death.
As a result of his work Michaels commented that, “Food safety managers are gambling with the odds of a Listeria monocytogenes outbreak or some other extreme event if they do not look at the science involving bacterial transfer and glove use. Conditions for cross-contamination can be disrupted by making scientifically based, food safe glove selection choices”
Considering the following takeaways when procuring your disposable gloves is essential to lower the risk of adverse foodborne events.
- Only choose disposable gloves with an AQL of 2.5 or less—pay for gloves that are suitable for food handling. The cost of an inferior glove is low, but failure rates can be high.
- Beware of cheap imports that may be reject clearance lines—you may be paying for glove failures and the potential spread of bacteria and virus.
- Prevent glove fraud by purchasing from reputable suppliers with quality control procedures in place and known raw material content of gloves.
- Purchase cost-effective nitrile gloves to reduce the risk of cross-contamination of food.
- Following correct hand hygiene is essential. Effective handwashing procedures, including washing around and under fingernails, limit microbes exposed to the damp inner glove environment.
Ardagh is CEO and founder of Eagle Protect PBC, which specializes in the supply of food safe disposable gloves and clothing, while Ronaldson is VP of marketing at the organization. Reach Ronaldson at Lynda@eagleprotect.com.