Freezer bags are very useful for storing all kinds of food and liquids, but are they safe?
There is growing evidence that storing food in plastic can lead to the transfer of harmful chemicals, which negatively effect our hormonal health in particular.
The transfer of chemicals is typically greater when plastic is heated, for example when pouring warm soup into a freezer bag.
One of the most well-known harmful chemicals found in plastic is BPA, which stands for bisphenol A. The main worry with BPA is that it is a xenoestrogen, which means it acts in a similar way to the hormone oestrogen.
This might not sound so bad, but artificially raised levels of oestrogen due to exposure to BPA have been linked to the following health conditions:
- Increase risk of miscarriages (source)
- Lower sperm count (source)
- Lower birth weight when mother is exposed to more BPA (source)
- Higher blood pressure (source)
- Higher rates of obesity (source)
It’s important to note that research into the health effects of BPA is still inconclusive, and most of us are only exposed to very small amounts of the chemical in our day-to-day lives. Correlation does not equal causation, so the effects in the studies linked to above aren’t necessarily caused by BPA.
Given the potential dangers of BPA, you may be wondering why it was ever used in the first place. BPA-based plastics are versatile and cheap, which explains why the material became so widely used despite health concerns.
Unfortunately, “BPA-Free” doesn’t necessarily mean safe. Several studies have shown that BPA-free plastics can be just as unhealthy, and sometimes even worse.
If you’re looking for BPA-free freezer bags, we have listed some below. However, a healthier option would be to avoid using plastic freezer bags where possible, and instead store things in glass.
Research suggests that plastic leaches more chemicals when it is heated. Therefore, if you decide to store food in plastic freezer bags, you should wait until it has cooled before transferring it to the bag. You should also avoid microwaving and heating (for example in sous vide cooking).
BPA-Free Freezer Bags in the UK
Ziploc Heavy Duty Freezer Bags
Ziploc bags are now all BPA free. They’re also recyclable and are free from dioxins (a type of toxic pollutant).
Ziploc bags are some of the toughest and most reliable on the market. The particular bags shown here can hold a quart liquid (almost a litre).
Kitzini Reusable Food Bags
These reusable food bags are made primarily from silicone, which is BPA free. Silicone isn’t completely natural, but it’s generally regarded as a safer and more environmentally friendly alternative to plastic.
These food bags can be used in the freezer, but not in the microwave as the plastic sealing strip will melt.
Kitzini’s food bags have a capacity of one litre and come in packs of four, so they work out a bit more expensive than plastic freezer bags. The bags are leakproof, and can be used to store liquids such as soups.
Lakeland Zip-Seal Freezer Bags
These freezer bags from Lakeland measure 18 x 20 cm and have a zip seal just like Ziploc bags. They have a write-on strip so you can label your food easily.
These bags are quite tough, and can be reused several times.
Alternatives to Freezer Bags
There are lots of plastic-free alternatives to freezer bags available. Some of the options include:
- Glass jars
- Glass trays
- Aluminium foil
- Stainless steel food containers