Safety Aspects of Handling Isocyanates in Urethane Foam Production

A Classic IChemE Paper on Isocyanate Hazards, Process Safety and Exposure Control

LEVCentral Expert Commentary

Although written many years ago, this IChemE paper remains a fascinating resource for anyone involved in the manufacture, handling or control of isocyanates. The paper provides an overview of the safety considerations associated with the production of urethane foams and discusses both the process hazards and occupational health risks presented by polyisocyanates.

The author explains how materials such as toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI) and related compounds became increasingly important as building blocks for foams, coatings, elastomers and adhesives. The paper highlights that whilst these materials offer significant commercial benefits, they also require careful handling because of their reactivity and toxicity.

For modern LEV professionals, the paper provides useful historical context. Many of the challenges discussed remain familiar today, including the need to prevent inhalation exposure, control spills and leaks, manage storage arrangements and ensure that process equipment is designed to minimise the release of hazardous substances. Whilst modern standards, regulations and control technologies have evolved significantly since the paper was written, the fundamental principles of exposure prevention remain largely unchanged.

The paper is particularly interesting because it predates much of the modern guidance surrounding occupational asthma and biological monitoring. It therefore offers valuable insight into how industry understanding of isocyanate hazards developed and why engineering controls, ventilation systems and exposure monitoring became such important elements of workplace risk management.

For those involved in occupational hygiene, LEV design or polyurethane manufacturing, the document provides an opportunity to understand the historical foundations of many of the control measures now regarded as industry standard.

View Original Paper

Source Document

View Original HSE Guidance

Source: E. Corbett, A.R.I.C. Institution of Chemical Engineers (IChemE)
Document Type: Technical Conference Paper
Status: May 1963
Last reviewed by LEVCentral: June 2026

Key Learning Points

Isocyanates are highly reactive chemicals widely used in polyurethane and urethane foam manufacture.
Common isocyanates include TDI, MDI and naphthalene diisocyanates.
The reactions involved in polyurethane manufacture can be vigorous and require careful process control.
Exposure prevention is a critical component of safe isocyanate handling.
Engineering controls and ventilation systems play an important role in reducing exposure risks.
Storage, transfer and handling arrangements require careful design and management.
Understanding chemical reactivity is essential when developing safe systems of work.
The paper provides valuable historical context for the development of modern isocyanate control strategies.
Many of the principles discussed remain relevant despite significant advances in technology and regulation.

Further Resources

Recommended Learning

Thought Leadership

Many modern practitioners encounter isocyanates through spray painting, coatings, adhesives or foam production without fully appreciating the historical development of the controls now considered standard practice. This paper provides a valuable reminder that today’s control strategies were shaped by decades of industrial experience, incident investigation and occupational health research.

From a LEV perspective, the document reinforces an enduring principle: the most effective approach to controlling hazardous substances is to prevent their release in the first place. Where this is not possible, engineering controls such as containment and local exhaust ventilation become critical safeguards.

Whilst technologies have advanced considerably since this paper was published, the underlying philosophy of controlling exposure at source remains exactly the same today as it was when the paper was first presented.