Unhardened epoxy chemicals can cause asthma

Published online: August 1, 2018

Epoxy compounds are widely used in industrial and construction coatings, adhesives, and plastic composites. New uses such as pipe relining resins and 3D-printing materials have arisen in recent years. Epoxy resins usually appear in two-pack-systems, where uncured epoxy resin is mixed with polyamine hardener resulting in hard epoxy plastic. Unhardened epoxy compounds are well known causes of contact dermatitis, but it has been unclear whether they cause asthma.

In a study recently published in The Journal of Allergy and Clinical Immunology: In Practice, Suojalehto and colleagues described asthma patients who were tested with specific inhalation challenge tests in two specialized European centers (Helsinki and Madrid) between 1997-2018. All the patients had used unhardened epoxy resins at work. In specific inhalation challenge tests, the patients mixed epoxy chemicals in a laboratory similarly as at work and they were monitored to detect asthma reactions. Positive test results confirmed that their asthma was caused by these chemicals. The authors also measured fumes that vaporized during handling of epoxy compounds at the workplace and during the test.

Fifteen of 113 tested patients had positive results, i.e., asthma reactions caused by epoxy compounds. The asthma reactions usually appeared late, a few hours after the patients had stopped handling the chemicals. The patients most commonly worked as industrial painters, and they had used epoxy chemicals on average 10 years before the diagnosis. Two of them also had contact dermatitis caused by epoxy resin. Only very low levels of polyamine hardener were detected in the air measurements.

The study showed that some workers get asthma from unhardened epoxy compounds, although air levels of these chemicals are low. Asthma reactions may appear after work, which makes it difficult to connect asthma symptoms to these chemicals. Epoxy compounds can cause asthma only when handled as liquids, not as fully hardened epoxy plastics.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

Occupational asthma from epoxy compounds
Hille Suojalehto, Joaquin Sastre, Emilia Merimaa, Irmeli Lindström, Katri Suuronen

Close-up of pine tree branches in Winter Close-up of pine tree branches in Winter