Texas State Attorney General Ken Paxton has opened an investigation over whether or not Lululemon has misled the public over their claims of the safety and health of its products. Specifically, this is in regard to the alleged presence of so-called forever chemicals and microplastics. According to USA Today, Paxton said “I will not allow any corporation to sell harmful materials to consumers at a premium price under the guise of wellness and sustainability.” Lululemon sells upscale activewear under the claims of health & wellbeing as well as sustainability. Naturally, Lululemon denies the allegations of harmful substances in its activewear.

Lululemon has a website that presents its restricted chemicals list, RSL. Presumably this might remind vendors to avoid any of the many chemicals on the RSL. Just as importantly it serves as a public document to render intractable any legal liability for the presence any of the chemicals that a vendor may try to pass off in their work.

How this plays out is unclear. Lululemon will have to vigorously fight the allegations not only for itself, but for all of the other apparel manufacturers who also use perfluorinated substances made from PFAS and PFOS to provide water repellency.

What is a perfluorocarbon?

But first, what does ‘perfluorinated’ mean? The word is a verbal shortcut that makes these substances easier to talk about. The word breaks into 2 parts- ‘per’ and ‘fluorinated’. With chemical substances, ‘per’ indicates that the molecule in question has fluorine atoms attached to every part that would otherwise have hydrogen atoms. Take butane for example. The chemical formula is C₄H₁₀. It is a simple hydrocarbon substance consisting of only two chemical elements, 10 hydrogen atoms and 4 carbon atoms. It is the fuel in your butane lighter.

Perfluorinated butane in this simple example would have the formula C₄F₁₀. Every hydrogen from the butane – C₄H₁₀– is replaced with fluorine. Fluorine is a gas much like chlorine but is a much more reactive chemical. It attacks most substances except fluorinated materials like Teflon(TM). Carbon-based substances containing fluorine are also called fluorocarbons. This class of substances finds considerable use in refrigerants and fire extinguishing foams.

Fluorine- The savage beast

Fluorine is commonly supplied as 20 % mixture of F₂ in nitrogen, helium or argon. Organic and inorganic substances are known to vigorously ignite on contact with fluorine gas. Interestingly, no reports of lethal effects have been reported by inhalation of the dilute gas. This might be due in part to the extra care chemists use when handling it. Like chlorine and bromine, dilute fluorine can cause severe irritation of the nose and eyes.

Many drug molecules on the market contain one or several fluorine atoms connected to the structure. A fluorine atom is very similar in size to a hydrogen atom so it’s contribution to drug activity is not based on steric bulk. Fluorine groups a drug molecule can bring increased lipophilicity and increased resistance to metabolic degradation. The presence of fluorine atoms can help the drug molecule to better pass through the blood/brain barrier or raise the compatibility and binding strength with hydrophobic features on the target molecule.

It turns out that the features that suppress metabolic degradation in the body also suppress biodegradation of excreted fluorinated drugs in water treatment plants and in the environment. This leads to soil and water accumulation and potentially bioaccumulation in the food chain.

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National Research Council (US) Committee on Acute Exposure Guideline Levels. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 8. Washington (DC): National Academies Press (US); 2010. 5, Fluorine Acute Exposure Guideline Levels. Available from: https://www.ncbi.nlm.nih.gov/books/NBK220011/