PU foam, health and occupational safety
PU foam is a technical chemical product. It insulates well and is easy to work with. As with any tool, you should find out how to use the product safely and know the general health and safety regulations before using it. This means ensuring good ventilation, wearing safety goggles and gloves. We will tell you why.
Respiratory organs and skin contact
The constituent isocyanate (MDI) in the construction foam has the most impact on health. Respiratory organs may be irritated, if free isocyanate is inhaled in concentrations above the workplace tolerance levels.
If PU foam cans are used normally, the workplace tolerance is not usually exceeded. Nevertheless, we recommend ensuring that the areas in which the PU foam is used are well aired because sensitive persons can suffer hypersensitive reactions to even the smallest of amounts of MDI.
If fluid polyurethane comes into contact with the eyes, this may cause light or moderate irritation and injuries to the cornea, however these are reversible. It is always best to wear goggles.
Protect your eyes with safety goggles
If it is already too late for this recommendation and your eyes have been in contact with diisocyanate, apply these
First aid tips
- rinse the eyes with plenty of water for at least 15 minutes
- hold the eyelids wide open when rinsing
- do not wear contact lenses after the contamination
- go to an ophthalmologist as soon as possible
Clothes protect your skin
The same applies for contact with skin. Before it has hardened, polyurethane can irritate the skin. Also, the foam adheres strongly and cannot be removed easily from the skin. To protect yourself when working with PU foam, it is recommended that you wear clothes and clothing that covers all skin.
If PU foam has gotten on your skin despite all your precautions, the best way to remove it is with cooking oil or baby wipes containing oil while the foam is still fresh. You can carefully rub off dried foam. You should avoid using solvents at all costs.
If knowing the exact chemical composition is important for health treatment, the UFI code, which must be printed on every can, will help you. You can find the information here.
You’ll find more tips on how to remove PU foam from places where you do not want it here.
Safe handling of compressed gases
Using spray cans is so normal that it is easy to forget that there is a risk of explosion connected to the compressed gases. Whilst accidents with PU foam cans are very rare, most cases are due to negligent use of the compressed gases, often because they are used directly adjacent to open flames or a can is damaged. The following are important precautions, because explosions are impossible without external influences.
- Even if a small dent seems harmless: never work with damaged cans! The slightest of damage can weaken the can to the extent that it is unable to withstand the pressure of the gas when used and explodes.
Here is some advice about transport and storage.
- When working with compressed gas cans, you should keep away from open flames and never use lighters to check your work.
- Also, never heat a can too quickly because the compressed gas may also expand too quickly.
Here you can find more advice about working with PU foam in winter
- It is also important that PU cans are never left in cars, if it is possible that the inside of the car could heat up in the sun.
Here is some advice about transport and storage
- The smaller the space in which you are working, the more careful you must be. Do not use PU foam, if you are working in narrow shafts that you cannot ventilate properly.
Emissions from cured construction foams
Fully reacted, cured polyurethanes no longer contain isocyanates and therefore do not pose any health hazards due to the evaporation of MDI.
The competition-neutral EMICODE classification system is used to assess to what extent vapours are created when using parquet flooring, paints, varnishes, protective treatments for upholstery or even insulating materials, such as PU foam.
The system defines three quality levels: EC1plus (= very low-emission), EC1 (= very low-emission) and EC2 (= low-emission). Originally the EMICODE was developed for adhesives and sealing agents used on large surfaces, such as parquet flooring adhesives.
For the past couple of years it has also been possible to test sealing agents based on the strict EMICODE guidelines which are used in much smaller quantities compared to e.g. PU foam. PU foams that were tested were classified as very low-emission with the label EC1plus (= very low emission).
You can read more about the Emicode here Emicode.
Is construction foam carcinogenic? (Classification as H351 according to GHS)
According to the globally harmonised system for the classification and labelling of chemicals (GHS) used within the European Union, PU foam must bear the H351 statement. H351 states that products may have a carcinogenic effect.
This suspicion is based on a laboratory test carried out at the beginning of the millennium.
When setting up the test, the MDI was changed so that it was inhaled for a longer period. However, this inhalative mixture of substances is not created when PU foam is used normally.
There is a brief summary of the study results on the safety data sheet issued by ISOPA.
Compulsory training for construction foam cans
Starting on August 24, 2023, all craftsmen and industrial workers who work with PU foam must have received training. There is even an obligation to provide proof of this. This is what the European Chemicals Agency ECHA has stipulated.
The training obligation for working with polyurethanes was introduced primarily because of the MDI exposure mentioned under “Respiratory tract and skin contact” and the possible sensitisation of the respiratory tract and skin. The training obligation is intended to protect employees who regularly work with polyurethanes because, in general, most accidents in the workplace are due to incorrect handling. Do-it-yourselfers who only occasionally work with PU foam are not affected by this regulation.
On behalf of the industry, the European Federation of Adhesives and Sealants Industry (FEICA) has prepared online training courses. On our page , you’ll find the links to these online training courses and learn how to register for the courses.
You can also find the most important safety tips on our site Working safely with PU foam.