Do synthetic fabrics pose a health risk?

Question

Background

I've seen a large number of health blogs that describe polyester, rayon, acrylic, and nylon as harmful or toxic (usually due to chemicals used during the manufacturing process). Some examples include:

• Claims that synthetic fibers are manufactured with toxic chemicals: https://fashionbi.com/newspaper/the-health-risks-of-toxic-fibers-and-fabrics
• Claims that bodyheat causes polyester to out-gas harmful molecules: https://www.thehouseofpillows.eu/polyester-shouldnt-be-in-your-bed-blog/
• Claim that polyester traps odors and facilitates harmful bacterial growth: https://www.whowhatwear.com/worst-fabrics-for-skin

I know that the internet is prone to blow things out of proportion, especially when it comes to supposedly toxic household items. I don't know enough to assess these claims myself, which is why I'm posting here.

From my perspective, it seems like any residual chemicals used in the manufacturing of synthetic fabrics should come off in the wash. In addition, many of the sites may be connected to a company that's trying to advertise alternatives to polyester, and these sites may be especially prone to exaggeration or misinformation.

Question

Are there health concerns related to the use of polyester or other synthetic fabrics in clothing and mattresses?

Answer 1

Sources mentioned in the question (Fashionbi.com, Thehouseofpillows.eu, Whowhatwear.co.uk) claim that certain synthetic fabrics and related chemicals can cause health problems:

• Polyester: skin, lung and heart cancer, chronic respiratory infections, dermatitis, reduced sperm count and behavior changes
• Rayon (from recycled wood pulp or bamboo cellulose; involved chemicals: carbon disulfide, sulfuric acid, ammonia, acetone and caustic soda): nausea, headache, vomiting, chest and muscle pain, insomnia, tissue necrosis, anorexia and Parkinson’s disease
• Acrylic: breast cancer
• Nylon (involved chemicals: caustic soda, sulfuric acid, formaldehyde, chloroform, limonene, pentene and terpineol): cancer, skin allergies, dizziness, headaches, spine pains

A search through studies (mainly on PubMed) and reports of related US government institutions reveals the association between certain fabrics and contact/allergic dermatitis, but not with any type of cancer or other significant health problems. (I did not include studies about occupational textile-related diseases and studies about dyes.)

Evidence:

1) In 2010, U.S. Government Accountability Office found excessive amounts of formaldehyde in some cotton clothes produced mainly in Asia, but not in synthetic fabrics. They say the main health risk is allergic contact dermatitis and that washing reduces but not always successfully removes all formaldehyde.

2) Giovanna Luongo from Stockholm University in his 2015 doctoral thesis Chemicals in textiles, 2015 mentions formaldehyde, dyes and certain other chemicals that can be found in clothes, but, except dermatitis, does not provide any evidence about other related health risks.

3) A review article Textile dermatitis (Contact Dermatitis, 1994) mentions formaldehyde-related resins as the main cause of textile dermatitis.

4) There are many anecdotal reports of excessive sweating when wearing polyester clothes.

In conclusion, very few studies mention the association between synthetic fabrics and health problems. One of the most commonly mentioned substance that is found in fabric is formaldehyde, but this is more likely found in cotton than in synthetic fabrics.