Isocyanates require much caution

People exposed to isocyanates can develop serious health problems and symptoms can appear in a short time, so workers handling them must be given special training. In some cases, medical check-ups are also required.

Isocyanate is the collective name for a group of chemicals used in several areas, particularly in the production of different forms of polyurethane plastic (PUR) which occurs in a wide variety of materials. On board ships they are found in varnish, adhesives, insulation materials and two-component paint. Polyurethane foam is often used to insulate cold rooms and in some cases to insulate the hull. Such products are durable and have good insulation properties, but they can also be very harmful to those who apply them. The chemicals can be absorbed into the body through inhalation, skin or eye contact, and can lead to headaches and a runny nose and in the long term eczema, asthma and lung damage. Per Leanderson is a toxicologist at the department of occupational and environmental medicine in Linköping and has carried out research on isocyanates. He says that these chemical compounds can be very harmful and that the symptoms may appear quickly. 

“High exposure on a couple of occasions may be sufficient to cause damage, so not much is needed to result in illness.” says Per Leanderson. 

Exposure to isocyanates takes place in different ways, such as drops of two-component paint or varnish on the skin. Spray painting uses very fine paint droplets that are easy to breathe in and that can carry isocyanates deep into the lungs. Hardened paint does not pose a health hazard, but when hot work on painted surfaces or abrasive work on materials containing isocyanates is carried out, harmful substances can be released. 

“Inhaling welding fumes or dust landing on your skin can be harmful.  Welding smoke contains small particles that can carry isocyanates into the lungs,” says Per Leanderson. 

There is little evidence that decomposing isocyanate materials, such as flaking two-component paint or crumbling isocyanate insulation, pose a significant health risk. On the other hand, you should be careful about dust in all types of work, says Per Leanderson. 

High exposure on a couple of occasions may be sufficient to cause damage, so not much is needed to result in illness

“You should always protect yourself from dust, no matter what kind it is. A simple dust filter is enough instead of the carbon filters that are commonly used when working with isocyanates.” 

Due to the risks associated with isocyanates, the Swedish Work Environment Authority has low limits for exposure to this group of chemicals and those who work with such products must have special training. Training is required for the person who supervises such work as well as those who perform it, and the training certificate must have been issued within the last five years. If an employer cannot show a valid certificate, there is a penalty of SEK 10,000 for each employee without such a certificate. The employer must also arrange medical check-ups for those who work with di-isocyanates, a variant of isocyanates. 

“Knowledge and risk analyses are required for all safe work with isocyanates. You have to know where the material is, how it should be handled and what equipment and personal protective equipment the work requires,” says Per Leanderson. 

By law, harmful products must be replaced by safer products when possible. If it is not possible, workers must be protected through good extractor fans and plenty of ventilation. In cases where there are still health risks, exposure must be reduced through personal protective equipment. 

“You need respiratory protection against particles as well as gas through some kind of carbon filter. The whole face needs to be protected and any bare skin on the body. All the equipment can be a bit cumbersome but you must protect yourself,” says Per Leanderson. 

Risk assessment of work with isocyanates

The Swedish Work Environment Authority regulation on chemical work environment risks, AFS 2014: 43, states that work involving isocyanates must be preceded by a thorough risk assessment that is documented in writing. The following must be kept in mind in such risk assessments for isocyanates:  
• Where and when there is a risk of isocyanate exposure through inhalation or skin contact. Check whether there is a risk of isocyanates forming during hot work. 
• What protective measures must be taken to keep the exposure as low as possible. 
• Tasks that require personal protective equipment and what must be used. 
• How to handle contaminated work equipment and personal protective equipment safely. 
• How to check and maintain work equipment and ventilation
Source: Prevent
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