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The Danger of Cooking and Baking Bags
First and foremost, to avoid any misconception, these bags are made out of plastic, and the question discussed below is: Are these bags safe to use? Given that most Plastic Products Release Estrogenic Chemicals?
What material is used for the bags
Leakage of plastic nano prticles
Plastic Extra Substances
Regulatory limits change from time to time. The discussion below brings to light some of the risks of these nanometer-sized particles.
Additionally, "Previous studies have shown that some plastic materials, including polypropylene used for baby bottles and polyethylene terephthalate used for tea bags, can shed microscopic and nanoscale particles into heated liquids",
Note that some of the health problems with synthetic polymers come from the extra substances (toxins) inside the matrix that can migrate out of it!
Plastic Extra Substances
Some of these extra substances are add to improve the polymer’s “qualities”:
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Plasticisers - materials that, among other things, give flexibility and strength to the bag. These are substances with small molecules that can easily migrate from the plastic medium, especially in the presence of oil. The most commonly used are phthalates of various kinds. (Read here more about phthalates), Potential problems: phthalates are substances that act as synthetic hormones (endocrine disruptors) and can bind to estrogen receptors in our body and activate or paralyze them.
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Antioxidant substances - which protect against oxidation processes such as exposure to UV radiation, free radicals formed at high heat (for example during baking), exposure to infrared radiation and microwave radiation, and more. Among the commonly used substances is bisphenol A (BPA), which also acts as a synthetic hormone that binds to estrogen receptors in our body.(Read More)
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Lubricants - which, among other things, prevent adhesion, reduce friction, reduce static electricity, increase shine and transparency, and more. The common materials for this role are synthetic fatty acids, wax and more (Read More).
Most of the cooking/baking bags are made of polyamides (nylon) of two main types: nylon 6 (polycaprolactam) or nylon 6/6 (a completely different material despite the similar name).
These types of nylon were chosen for the job due to being resistant to high temperatures (melting temperature of 218 degrees and 264 degrees Celsius for nylon 6 and nylon 6/6 respectively), due to their high vapor permeability and due to their ability to actually absorb water during use (a feature that gives them more strength).The manufacturers of the baking bags do not bother to indicate, neither on the packaging nor on their websites, what exactly they add to the production of the baking bag, therefore we do not have information about this or that brand, but information about baking bags in general.
Beware the nanoparticles leakage: Nylon cooking bags and plastic-lined cardboard cups are conveniences many people rely on!,
A new study (Published - April 2022) in ACS’ Environmental Science & Technology suggests that they are an underappreciated source of nanoparticles. They report that the plastic in these products release trillions of nanometer-sized particles into each liter of water that they come in contact with. That sounds like a lot, but the team notes that these levels are under the regulatory limits for consumption.
Phthalates in the plastic
Materials "Spilled" from the Plastic Bags
Cooking/baking bags alternatives
Some are residual materials from the production process:
Monomers and oligomers that did not react in the production process - there is almost always a residual amount of monomers and oligomers (remember? structural units with short and medium molecules), either due to an incomplete chemical process or due to a chemical equilibrium in which there is always a bit of the opposite reaction (decomposition instead of construction) . These substances can have a wide range of toxicity depending on the type of substance due to their high ability to migrate out of the medium of the substance into the food. In the case of the nylons in question - the monomer caprolactam is found in nylon 6 and is toxic if swallowed, and the monomers found in nylon 6/6 are hexamethylenediamine which is toxic if swallowed, and adipic acid for which there is no indication of toxicity if swallowed (Read More).
Some are materials that are not there on purpose but originate from an unclean production line.
Of course, manufacturers would claim that these toxins are not added to their polymer products, but even if these claims are trustworthy (Read here more on how trustworthy they are), the toxins that are the result of unclean production line, can only be discovered with certainty by an analytical test in a laboratory and unfortunately, the authorities responsible for public health do not perform these tests.
In summary of the above - the common cooking/baking bags have a high potential for leaking very problematic toxins most notably Phthalates that are endocrine disruptors - acting in the body like hormones!
Phthalates
“Phthalates are a series of widely used chemicals that demonstrate to be endocrine disruptors and are detrimental to human health. Phthalates can be found in most products that have contact with plastics during production, packaging, or delivery. Despite the short half-lives in tissues, chronic exposure to phthalates will adversely influence the endocrine system and functioning of multiple organs, which has negative long-term impacts on the success of pregnancy, child growth and development, and reproductive systems in both young children and adolescents”.
The field of environmental hormone disruptors is a relatively new field of research in the world of toxicology. For this reason and in light of the unique property of toxicity even at minute doses of individual particles per million or even a billion (which are very, very low concentrations) - there are still no current standards, nor Sufficiently sensitive and available measurement means, which can give both the manufacturers and us the consumers a benchmark for the product's safety
Toxins "Spilled" from the Plastic Bags
What did studies that looked for spillage of specific materials from baking bags find?
In a 1998 study that was done to test the migration of materials from baking bags of the nylon 6 and nylon 6/6 types, the meat, skin and cooking juices of chicken cooked in the above types of bags were sampled. They tried to identify both volatile and non-volatile substances that migrated from the bags to the food. The study found a significant concentration of monomers and oligomers (seven predefined types of monomers and oligomers were identified) originating from the bags in the chicken meat which accounted for 16% of all the non-volatile substances identified, as well as the presence of a volatile compound - cyclopentyl cyclopentanone! In 1997, The same group of researchers has identified a long list of volatile substances emitted from the aforementioned cooking bags [Cyclopentanone (31.7 mg/bag), cyclopentyl cyclopentanone (17.4 mg/bag), hexadecane (2.6 micrograms/bag), heptadecane (3.2 micrograms/bag), octadecane (3.0 micrograms/bag) and epsilon-caprolactam (5.0-35.5 mg/ bag)], and also that the monomers and oligomers found in the first study mentioned, migrated in a high amount to olive oil heated in the baking bags.
Another study from 2007 that examined a specific leakage of antimony (heavy metal) used as a catalyst in the production process of PET plastic used for baking bags, found that half of the products tested released levels of antimony that exceeded the then permitted level of antimony in contact with food.
Note, what WIKI writes "An oven bag, cooking bag or roasting bag is a bag used for the roasting of meat or other food in an oven. They may be made of heatproof nylon or sometimes with food grade polyethylene terephthalate (PET)"
To sum it up: The studies as presented above show that there is a leakage of toxic substances from cooking/baking bags.
Cooking bags alternatives:
Oven roasting using heat-resistant dishes with lids such as pyrex, coated clay pots or cast iron pots, tagine, and more, after validating that they comply with the standard for heavy metals and are of high quality. You can also use cotton fabric bags for cooking (with adjustment of the amount of water that you add to the stew).
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