Table 1.

Characteristics and sources of parent VOCs and respective urinary biomarker measured.^a

Parent Compound	Biological Half-Life	Biomarker Chemical Name	Biomarker Abbreviation	Sources of exposure in hair salons, thru products used and services provided^a	Other common sources of exposure, outside of hair salons
1,3-Butadiene	10 hours³²	N-Acetyl-S-(3,4-dihydroxy butyl)-L-cysteine, N-Acetyl-S-(4-hydroxy-2-butenyl)-L-cysteine	34BMA, 4HBEMA	hair fixers, shampoo, nail polish, sunscreen, moisturizer, body wash/cleanser, eyeliner, bronzer^33–37	tobacco smoke, vehicle exhaust, waste incineration or wood fires, tires, various synthetic rubber products, paints, aerosol sprays, nitrile gloves^35,38–41
1-Bromopropane	up to 6.2 hours. Bromide ion takes longer to expel⁴²	N-Acetyl-S-(n-propyl)-L-cysteine	1-PMA	scissor lubricant³⁵	aerosol spray, adhesives and spot removers, glass cleaner, wood surface cleaner, textile cleaning solvent, metal-degreasing solvent, paints^35,38,40,43
5-Hydroxymethylfurfural	up to 6.2 hours at 2,700 ppm. Bromide ion takes longer to expel. Varies with concentration of gas⁴⁴	5-Hydroxymethyl-2-furoic acid, 5-Hydroxymethyl-2-furoylglycine	HMFA, HMGA	N/A—used in cosmetics in general, but no details provided on actual products^45,46	cigarette smoke, beverages and foods⁴⁰
Acrolein	10 hours⁴⁷	N-Acetyl-S-(3-hydroxypro pyl)-L-cysteine, N-Acetyl-S-(2-carboxyeth yl)-L-cysteine	3HPMA, 2COEMA	hair fixative, artificial nail builder⁴⁸	tobacco smoke, automotive exhaust, oil or coal fired plants, cooking oil^38,39,41
Acrylamide	up to 25 hours (2CAHEMA), up to 17 hours (2CAEMA)⁴⁹	N-Acetyl-S-(2-carbamoyle thyl)-L-cysteine, N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine	2CAEMA, 2CAHEMA	shampoo, nail polish, hair styling gel, conditioner, styling mousse/foam, hair treatment/serum, detangler, anti-wrinkle cream, day cream, night cream, eye cream, mattifier, make-up removal cloths, serum, eye treatment, mascara, makeup primer, bath oil/salts, body wash, moisturizer^35,37,50	tobacco smoke, carbohydrate-rich foods such as potatoes cooked at high temperatures, contaminated well water, working in the production or use of acrylamide and acrylamide containing products, soil conditioning agents, spot treatment, liquid fabric conditioner^35,38,40,41
Acrylonitrile	7–8 hours⁵¹	N-Acetyl-S-(2hydroxyethyl)-L-cysteine, N-Acetyl-S-(1-cyano-2-hy droxyethyl)-L-cysteine, N-Acetyl-S-(2-cyanoethyl)-L-cysteine	2HEMA, 1CYHEMA, 2CYEMA	hair wigs and extensions, body wash, perfume, nitrile gloves^35,52,53	tobacco smoke, industrial sources or hazardous waste sites, synthetic and acrylic fibers of textiles, resins, plastics, and rubber for a variety of consumer goods^38,40,41
Benzene	up to 1.2 hours^54,55	Muconic Acid, N-Acetyl-S-(phenyl)-L-cysteine	MUCA, PHMA	hair styling cream⁵⁰ hair styling cream⁵⁰	tobacco smoke, automobile service stations, exhaust from motor vehicles, and industrial emissions, dishwasher liquid detergent, laundry soap^35,38
Carbon disulfide	6.5 hours⁵⁶	2-Thioxothiazolidine-4-carboxylic acid	TTCA	N/A	tobacco smoke, manufacturing processing (e.g. rayon and rubber products), but likely not found in the final product^38,39,57
Crotonaldehyde	< 1 day⁵⁸	N-Acetyl-S-(3-hydroxypro pyl-1-methyl)-L-cysteine	3HMPMA	perfumes and fragrances⁵⁹	tobacco smoke, gas cookers, gasoline and diesel engine exhausts, and smoke from wood burning, naturally occur in some foods, uncontrolled hazardous waste sites³⁸
Cyanide	20 minutes - 1 hour⁶⁰	2-Aminothiazoline-4-carboxylic acid	2ATCA	N/A	Tobacco smoke, found in cyanide containing foods, used in plastic production of dyes, but insignificant amount released, environmental pollution from mines, metallurgical plants, and exhaust gas from vehicles^38,61
Ethylbenzene / Styrene	8 hours⁶²	Phenylglyoxylic acid	PHGA	sunscreens, moisturizer with SPF, nail polish, body firming lotion, facial sun care, body wash/cleanser, facial moisturizer/treatment, eye liner, mascara, foundation, BB cream, facial powder, makeup with SPF, lip balm, facial cleanser, serums & essences, baby soap, toners/astringents, eyelash glue, tanning sprays, eye shadow, hair wigs and extensions, shampoo, hair styling aide, baby shampoo^37,63,64	tobacco smoke, vehicle exhaust, building materials, manufacturing, foods and beverages, foods packaged in polystyrene containers, liquid hand soap^35,38–41
Furfural	2 – 2.5 hours⁶⁵	N-2-Furoylglycine	N2FG	NA	flavoring agents for foods, Lysol All Purpose Cleaner^35,66
Isoprene	10.2 hours⁶⁷	N-Acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine	4HMBEMA	hair bonding glue, eye shadow, eyeliner, eyelash glue, face and body paint^37,68	rubber products, vehicle tires⁴⁰
N,N-Dimethylformamide	23 hours⁶⁹	N-Acetyl-S-(N-methylcarbamoyl)-L-cysteine	MCAMA	hair dye⁷⁰	tobacco smoke, building materials, glues^38,39,41
N-Methyl-2-pyrrolidone	4 hours⁷¹	5-Hydroxy-N-methylpyrrolidone	5HMP	antifungal nail treatment, mascara, nail polish remover,³⁷	paint thinners, glue, cleaning detergents^72,73
Propylene oxide	40 minutes⁷⁴	N-Acetyl-S-(2-hydroxypro pyl)-L-cysteine	2HPMA	conditioner, shampoo, texturizing cream, hair dye,^35,37	tobacco smoke, plastics industry, lubricants, oil demulsifiers, antimicrobial pesticides, building and construction materials^39–41,74
Styrene	2.2 – 9 hours^75,76	Mandelic acid, N-Acetyl-S-(1-phenyl-2-hydroxyethyl)-L-cysteine + N-Acetyl-S-(2-phenyl-2-hydroxyethyl)-L-cysteine	MADA, 1PHHEMA + 2PHHEMA	hair wigs and extensions, shampoo, conditioner, hair spray, hair serum, shaving cream, perfume and fragrances, deodorant spray, body lotion, cologne, shower gel, body mist, face masks, body cream, hand cream^50,63,64	tobacco smoke, vehicle exhaust, building materials, manufacturing, foods and beverages, foods packaged in polystyrene containers^38–41
Toluene / Benzyl alcohol	52 mins for phase I 12.95 hours for phase II⁷⁷	N-Acetyl-S-(benzyl)-L-cysteine	BZMA	hair dyes, hair sprays, hair wigs and extensions, shampoo, conditioner, hair treatment/serum, hair bleach, hair styling aide, detangler, styling gel/lotion, styling mousse/foam, beach & sport sunscreen, lipstick, moisturizer, moisturizer with SPF, facial moisturizer/treatment, foundation, body wash/cleanser, fragrance for women and men, body firming lotion, lip gloss, eye shadow, facial-cleanser, serums & essences, baby sunscreen, mask, bronzer/highlighter, facial sun care, exfoliant/scrub, lip balm with SPF, hand cream, mascara, makeup remover, antiperspirant/deodorant, shaving cream, lip balm, eye cream, facial powder, BB cream, bubble bath, lip liner, toners/astringents, concealer, brow liner, eye liner, makeup with SPF, toothpaste, baby lotion, sunless tanning, body oil, blush, shaving cream (men’s), after shave, after sun product, bath oil/salts/soak, CC cream, foot moisturizer, mouthwash, body spray, oil controller, vapor rubs, anti-aging cream, baby bubble bath & wipes, bar soap, skin fading/lightener, lip plumper, tanning spray.^37,63,64	tobacco smoke, fossil fuels, dyes, industrial solvent, paints, paint thinners, liquid hand soap,^35,38,39,41
Vinyl chloride	4.1 – 4.6 hours in rats⁷⁸	N-Acetyl-S-(2-hydroxyethyl)-L-cysteine	2HEMA	hair spray⁷⁹	tobacco smoke, breathing contaminated air from plastics industries, hazardous waste sites and landfills, drinking water from contaminated wells^38,41
Xylene	1.5 hours⁸⁰	2-Methylhippuric acid, 3-Methylhippuric acid + 4-Methylhippuric acid	2MHA, 3MHA + 4MHA	conditioner, pressing oil, bleaching cream^35,37,81	tobacco smoke, gasoline, paint, varnish, shellac, rust preventatives, air emissions from paint industries and automobile garages^38,39,41

^a.

May include personal care and hair styling products.