Hazards of Spraying with Two-pack Paints containing Isocyanates

Our plain-English summary of Hazards of Spraying with Two-pack Paints containing Isocyanates, by F.H. Tyrer (1979).

The study

• Author: F.H. Tyrer
• Published: Journal of the Society of Occupational Medicine (1979)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This article is not about asbestos. It concerns two-pack polyurethane paints with isocyanate hardeners. The author, an Employment Medical Adviser in Bristol, described sprayers' case histories from 1974 to 1977. Several sprayers developed chest tightness, cough, wheezing or shortness of breath. One also developed a streaming nose and swelling around the eyes. In one case, symptoms cleared during time off work and recurred on return. At one garage, other employees also had chest symptoms. One sprayer became ill despite a satisfactory spray booth. One product label did not mention an isocyanate, though analysis found isophorone diisocyanate. In 1976 trade bodies agreed to recommendations. These included spraying only in booths or enclosures with effective exhaust ventilation, and airline breathing apparatus for all operators during spraying and until the mist had cleared. They also included excluding workers with a history of respiratory allergy and labelling hardeners as containing an isocyanate. In a later case the container warning was still inadequate. The author concluded that, without clear warnings, further sensitization cases were bound to occur in small garages and factories.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case series: individual case histories of paint sprayers, with a description of action taken
• Who was studied: Paint sprayers seen by the author as Employment Medical Adviser in Bristol. The case histories are dated August 1974 to November 1977, and several involved small garages and firms.
• Exposure: Spraying two-pack polyurethane paints whose hardener or activator contains an isocyanate
• Main results:
  • Case 1: a motor body sprayer had chest symptoms that cleared when he was off work and recurred shortly after he returned.
  • Case 1: the paint additive's container did not mention an isocyanate. Later analysis showed the material contained isophorone diisocyanate.
  • Case 2: at a garage, other employees as well as the young sprayer had chest symptoms.
  • Case 2: after correspondence with the author, the supplier amended its data sheet to refer specifically to spray booths.
  • Case 3: a sprayer developed a streaming nose, swelling around the eyes and chest tightness.
  • Case 3: the spray booth was described as unexceptionable, with effective exhaust ventilation.
  • In 1976, trade bodies agreed to a recommendation that spraying be carried out only in booths or enclosures with effective exhaust ventilation.
  • They also agreed that all operators should wear airline breathing apparatus during spraying and until the mist has cleared.
  • The agreed recommendations also included excluding workers with a history of respiratory allergy, and stating on the container label that the hardener contains an isocyanate.
  • In October 1976 the author was told of a paint sprayer admitted to hospital with apparent occupational asthma. He had used the same paint as in Case 2.
  • Case 4: the warning on the container was inadequate despite the agreed code.
  • Case 5: a self-employed sprayer had cough and wheezing, with chest tightness and shortness of breath, after spraying the same product as in Case 2. His workshop had no spray booth.
• The authors' conclusion: The author concluded that, unless clear and specific warnings about the hazard and precautions are given, many small garages and factories will use these paints in circumstances in which further cases of sensitization are bound to occur.
• Limitations the authors state:
  • In Case 6, the author states it was not possible to establish with certainty which material caused the sensitization.

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