k77 Isocyanate HDI

k77 Isocyanate HDI Scientific Information

Type:

Whole Allergen

Display Name:

Isocyanate HDI

Allergen code:

k77

WHO/ICD-11 code:

XM0YF6

(ICD-11 is currently under implementation by WHO and the ICD-11 codes displayed in the encyclopedia may not yet be available in all countries)

Route of Exposure

Main

Isocyanates are widely used in the production of polyurethane plastics, glues and paints. Individuals at risk are polyurethane foam makers, upholsterers, spray painters, wire coating workers, plastic molders, rubber workers, fabric coaters, metal rod coaters, truck body insulators and persons applying artificial turf and others.

Unexpected exposure

Isocyanates have been mentioned in relation to the Sick Building Syndrome.

Clinical Relevance

IgE-mediated reactions

A wide spectrum of potentially allergic respiratory symptoms have been described and up to 5% of exposed workers have been reported to have developed asthma at work (1). IgE antibodies to isocyanates have been found in 14-19% of sensitised workers (2, 3).

Other reactions

Non-immunological, irritative mechanisms are likely to be of importance.

Molecular Aspects

Cross-reactivity

The three isocyanates (TDI, MDI and HDI) are closely related structurally being HSA-conjugated haptens and there is some allergenic crossreactivity (2). However, the major specificity depends on the type of isocyanate exposure.

Compiled By

Last reviewed : June 2022

References

Baur X: Immunologic cross-reactivity between different albumin-bound isocyanates. J Allergy Clin Immunol 1983, 71, 197-205.
Butcher BT, Karr RM, O’Neil CE, Wilson MR, Dharmarajan V, Salvaggio JE, Weill H: Inhalation challenge and pharmacologic studies of toluene di-isocyanate(TDI)-sensitive workers. J Allergy Clin Immunol 1979, 64, 146-152.
Butcher BT, O’Neil CE, Reed MA, Salvaggio JE: Radioallergosorbent testing of toluene di-isocyanate-reactive individuals using p-tolyl isocyanate antigen. J Allergy Clin Immunl 1980, 66, 213-216.