Tosylamide/formaldehyde resin

Tosylamide/formaldehyde resin (TSFR) is a polymeric resin used as a plasticizer and secondary film-forming agent in nail polishes. While it was still in use as of 2023,^[update] its use has been diminishing in favor of hypoallergenic alternatives, due to the prevalence of reactions causing allergic contact dermatitis of the eyelids, face, and neck.

Tosylamide/formaldehyde resin

Names
Systematic IUPAC name poly[4-methylbenzenesulfonamide-alt-methanal]
Other names Toluenesulfonamide/formaldehyde resin Formaldehyde-p-toluenesulfonamide copolymer Santolite MHP Santolite MS
Identifiers
CAS Number	25035-71-6
ECHA InfoCard	100.132.132
EC Number	607-493-7
PubChem CID	159985
CompTox Dashboard (EPA)	DTXSID80933988
Properties
Chemical formula	(C8H9NO2S)n (n ≤ 10)
Molar mass	Variable (400–1900 g·mol−1)
Melting point	82 °C (180 °F; 355 K)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Production

TSFR is produced by condensing p-tosylamide [de] (often impure, containing o-tosylamide [de]) with formaldehyde. It consists of a mixture of short oligomers with repeating unit −N(Ts)CH₂−, terminated by −NHTs or −N(Ts)CH₂OH groups.^[2]

Allergenicity

Nail polishes containing TSFR were first introduced in 1939, becoming a major cause of allergic contact dermatitis of the eyelids, face, and neck.^[3][4] Allergic responses are caused by the water-soluble contaminants 5-tosyl-1,3,5-dioxazinane (TsN(−)(CH₂OCH₂OCH₂−)) and 3,5-ditosyl-1,3,5-oxadiazinane (TsN(−)(CH₂N(Ts)CH₂OCH₂−)), rather than formaldehyde, which is only present in trace quantities (<0.5%).^[3][4][5]

Since the early 2010s, the prevalence of allergic reactions to TSFR has decreased, due to the widespread use of hypoallergenic alternatives such as tosylamide/epoxy resin (first introduced in the late 1980s^[6]), cellulose acetate butyrate, and polyester resins (e.g. 2,2,4-Trimethyl-1,3-pentanediol [de]–isophthalic acid–trimellitic anhydride).^[7]

References

1. "Formaldehyde-p-toluenesulfonamide copolymer". CAS Common Chemistry. American Chemical Society.
2. Chiva, V.; Lecacheur, M.; Faure, R.; Gallo, R.; Wimmer, E. (15 July 1993). "Structure of Toluene Sulfonamide Formol Resins: Molecular Models from Mechanistic Schemes and Analytical Results". Journal of Applied Polymer Science. 49 (3): 461–467. doi:10.1002/app.1993.070490310.
3. Hausen, B. M.; Milbrodt, M.; Koenig, W. A. (September 1995). "The allergens of nail polish: (I). Allergenic constituents of common nail polish and toluenesulfonamide-formaldehyde resin (TS-F-R)". Contact Dermatitis. 33 (3): 157–164. doi:10.1111/j.1600-0536.1995.tb00537.x.
4. Park, Michelle E.; Zippin, Jonathan H. (January 2014). "Allergic Contact Dermatitis to Cosmetics". Dermatologic Clinics. 32 (1): 6. doi:10.1016/j.det.2013.09.006.
5. "Tosylamide/Formaldehyde Resin". Cosmetics Info. Personal Care Products Council. 2023-10-20. Archived from the original on 2024-01-10.
6. Sandewicz, Robert W. (2017). "Formulation of Nail Care Products". In Dayan, Nava (ed.). Handbook of Formulating Dermal Applications. Hoboken, New Jersey : Beverly, Massachusetts : Scrivener Publishing: John Wiley & Sons, Inc. pp. 539–590. ISBN 9781119364238.
7. Lee, Senhong; Maor, Danit; Palmer, Amanda; Nixon, Rosemary L. (September 2018). "Declining prevalence of allergic contact dermatitis caused by tosylamide/formaldehyde in nail polish". Contact Dermatitis. 79 (3): 184–185. doi:10.1111/cod.13020. Archived from the original on 26 May 2022.