Packaging – Plastic Wrap

In this series, we explore packaging ingredients. In this post, we look at the main ingredients that make up the food-safe plastic wrap we use at home.

What are food-safe plastic wraps and what do they do?

Plastic wraps are typically clear or lightly colored transparent food-safe coverings that cling to themselves and to food containers to form a seal.
The plastic wrap keeps foods fresh by protecting them from the air which can expedite spoiling and oxidation, preventing unwanted drying, and preventing undesirable moisture absorption. They can also help keep food odors contained.
Currently, plastic wraps play an important role in food preservation and safe transportation, helping to keep our foods fresh and safe which in turn can help reduce food waste.

What are food-safe plastic wraps made of? 

There are a few types of food-safe plastic wraps, the most common plastic wrap we use at home is made fromSubscribe for weekly updates_ low-density polyethylene.
Manufacturers used to make many food-safe plastic wraps from polyvinylidene chloride. However, manufacturers have phased out polyvinylidene chloride use due to potential environmental harm as well as concerns that plasticizers from the polyvinylidene chloride food wrap could migrate into food products. We may still find this ingredient on some food packaging, but it’s typically combined with another ingredient or a film that provides additional food safety properties (1,2,3). 

What is low-density polyethylene?

Low-density polyethylene is a thermoplastic that can be made into many different plastic products. We find this ingredient in plastic trays, snap-on lids, beverage containers, plastic wraps, and more.

Do manufacturers add other ingredients to low-density polyethylene? 

Sometimes, manufacturers will add additional ingredients like biofilms to plastic wrap such as low-density polyethylene. These biofilms are designed specifically for a food product to increase food preservation properties.
Plastic wraps for home use may contain an ingredient to help the plastic stick to itself, however, they do not typically contain other ingredients like biofilms.

Is it regulated?

The Food and Drug Administration (FDA) regulates packaging and materials that will come into contact with food through a premarket notification process (1). A premarket notification process involves the manufacturer submitting key data and safety points around the material demonstrating that the packaging or contact substance satisfies the FDA’s safety requirements.  

To get the required data points, manufacturers enlist researchers to perform a battery of safety tests evaluating the ingredient’s safety profile. Sometimes ingredients found in the packaging or contact materials will be present on food. The researchers will measure this residue in parts per million (ppm) or parts per billion (ppb) (1). Once they have results, they will calculate a safety profile using a risk assessment process.

Is low-density polyethylene microwave safe?

The USDA recommends following the manufacturer’s directions for microwaving or otherwise heating plastic wraps, in an overabundance of caution the recommend avoiding plastic wrap from touching your food directly during the heating process (1).

Are there new concerns around low-density polyethylene?

There are a few emerging research areas that scientists are exploring to ensure food safety. These include nanomaterials from biofilms that manufacturers may incorporate into low-density polyethylene packaging on an industrial scale, unintended contaminants migrating from packaging into products, and sustainability concerns (1,2,3). 
We’ve invited speakers to address these issues at our 2021 Science Symposium. More information on our symposium to come.

The good news.

In our daily lives, plastic wraps help keep our foods fresh and safe longer, reducing food waste. On an industrial scale, plastic wraps protect food from potential contamination and spoilage during their journey from their origin to our plates


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