Cooking is regarded as a science and rightfully so, but for those more adept at experimenting in the kitchen than in the lab, the complexity of plastics pertaining to food safety can be overwhelming. When it comes to food processing, packaging, and storing, there’s copious amounts of information to digest about the different types of plastics and their functions. And, knowing the difference between what’s safe versus not is vital for keeping consumers protected from any potential harm. Here’s the rundown on what you need to know on the subject, so you can be sure you have all the ingredients necessary to create the best possible food experience.
Food-Safe vs. Food-Grade
The first thing to note is that food-safe and food-grade are two different non-interchangeable terms. Just like in geometry how every square is a rectangle, but not every rectangle is a square, in the food industry every food-safe material is food-grade, but not every food-grade material is food-safe. Let’s discuss.
Food-grade is considered anything that’s okay to either consume or come in direct contact with food. This includes the non-toxic plastic materials used to create food manufacturing equipment, like the components of conveyor belts, and items used by chefs, like cutting boards made from HDPE sheets.
Food-grade material, however, is only considered food-safe if it is utilized per its intended use to prevent safety hazards. For example, a plastic storage container that is specifically manufactured for dry cereal cannot necessarily safely store hot soup – heat has the potential to break down the chemical bonds of the plastic, which causes toxins to contaminate the food, deeming it unsafe to consume.
Food-grade and food-safe materials are thoroughly reviewed and studied by the FDA’s Division of Food Contact Notifications office, which is made up of scientists including chemists and toxicologists. This team of experts perform studies and tests that decide if food-contact substances are meeting strict guidelines like outlining the temperature and types of foods the materials can come in contact with, as well as if those same items can withstand proper cleaning methods. If the item is considered food-grade or food-safe, it is understood to be FDA compliant.
What’s important to know about BPA
Used in the production of polycarbonate plastics and epoxy resins, highly contested BPA or Bisphenol A is an industrial chemical consumers and food industry professionals alike should take into consideration when choosing which plastics to use for packaging and storage. Concerns include the chemical seeping into food and beverages, possibly causing damaging health effects. However, the FDA, the governing body that closely checks, evaluates and conducts research on the subject, continues to authorize its use, assuring that at the very low levels in which people are usually exposed to BPA from food packaging, it is safe. Research has shown that the human body metabolizes and expels the chemical quickly, which means it’s very unlikely that it will accumulate enough to cause damage, even throughout a lifetime of typical exposure.
However, as new studies emerge claiming BPA is more detrimental to health than once believed, there are formal petitions cropping up in hopes of restricting the use of the chemical in plastics that contact food. When selecting BPA-free plastics, avoid the recycling symbols 3 and 7, as those items may contain the chemical. Another safety measure is to prevent chemical leaching by keeping products away from extreme heat like ovens, ranges, microwaves, dishwashers, etc.
Types of food-grade plastics
Now that you have a better foundational understanding of the safety aspects, let’s dive into the different types of food-grade plastics and what they’re used for. In general, recycling numbers 2, 4, and 5 are the safest.
#1 PET (Polyethylene Terephthalate)
Commonly used to make soda bottles, peanut butter jars, and salad dressing containers, Polyethylene Terephthalate is more rigid and impact-resistant than other food-grade plastics in the lineup. It’s stamped with recycling number 1 and is considered an FDA-approved food-grade material even after it’s recycled, however; leaching of estrogenic compounds – hormone disrupting chemicals – can occur when it’s reused. PET has antimicrobial properties and resists corrosion, making it a good choice for food storage.
#2 HDPE (High-Density Polyethylene)
Best for long-term food storage, HDPE food safe plastic is one of the most used options in household food packaging for a variety of reasons, including its lightweight feel yet extreme durability – after all, it’s what’s used to make milk jugs and grocery bags, both requiring an impressive strength-to-density ratio.
Industrial-grade, FDA, NSF, and USDA-approved food-quality HDPE sheets are safe, easy to clean and resistant to corrosion. The high melting point of HDPE sheets ensures they withstand boiling for sterilization purposes, but once temperatures are high enough, they can be easily molded into different shapes for a range of uses. Cutting boards made from HDPE sheets are known not to dull knives, and won’t harbor bacteria like wooden counterparts that aren’t allowed in commercial kitchens. It’s also used to make squeeze bottles for chocolate syrup and butter.
Stamped with the number 2 Resin Identification Code, HDPE food safe containers are recyclable, however, once recycled, the material must be examined by the FDA on a case-by-case basis before being used again for food-contact products.
At Acme Plastics, we offer HDPE food safe options including made-to-order cutting boards as well as HDPE Smooth SR sheets and rods that are approved for food processing.
#3 PVC (Polyvinyl Chloride)
Alternatively known as the ‘Poison Plastic’, PVC has quite the reputation in the food industry for leaching chemicals like BPA and phthalates, which have the potential to negatively affect your health. However, food-safe PVC (or uPVC, which stands for unplasticized Polyvinyl Chloride) is a safer option said to be produced without the use of those toxic chemicals. While PVC cannot be recycled, uPVC is easily recycled and reused. In fact, cling wrap was previously made using PVC, but is now more commonly produced from LDPE, which brings us to number 4.
#4 LDPE (Low-Density Polyethylene)
Recycling number 4, LDPE has a lower tensile strength – the maximum force an item can endure before breaking – than HDPE food safe plastic, and is therefore not nearly as rigid. It’s used to make more flexible food-grade products, like the plastic bags used to package bread and sandwiches. Although not always recyclable, LDPE is easily reusable.
#5 PP (Polypropylene)
Polypropylene, recycling number 5, is an FDA-approved food contact plastic that’s generally used for single-serve items like yogurt cups, cream cheese containers, and syrup packets. Because of its high melting point, it can withstand the extreme temperatures of the microwave and dishwasher. It is also used in the production of reusable containers that can safely store leftovers. It’s lightweight, flexible, and resists breaking even when bent repeatedly, which makes it ideal for hinges on condiment bottle caps as well.
Acme Plastics offers custom options of polypropylene sheets that can be cut to suit the thickness and size you need.
#6 PS (Polystyrene)
While not necessarily considered the most popular or safest choice of the bunch, Polystyrene is FDA-approved as a food-grade material. It’s used to make Styrofoam® cups and “clamshell” takeout containers, as well as egg cartons and plastic utensils. Studies have shown that it may leach the chemical compound styrene into food products, especially once heated in the microwave, but the levels are low enough for item not to be considered a concern by officials.
When considering the use of Polycarbonate materials, it’s of course important to take into account the often-discussed debate over the safety of BPA. The FDA-approved good-grade material is used to make candy molds, hospital trays and serving bowls. It features the recycling number 7, or ‘other’, as it’s lumped in with plant-based bioplastics that are being developed as a possible safer alternative to Polycarbonates.
Talking about food-safe plastics with food companies
When approaching the subject of plastics with food companies, it’s important to be prepared with knowledge about what could be potential safety concerns for some. Focusing communication regarding food-grade versus food-safe products to the company’s product or packaging needs lends client confidence. Safer alternatives are always worth mentioning, as is the public concerns over certain FDA regulations, and how that may affect their products, manufacturing or the way they conduct business in the future.