Safely Using Isocyanates - Cameleon Paints | Industrial Coatings | Protective Coatings | Toll Manufacturing | Textured Coatings

HEALTH EFFECTS OF ISOCYANATES

Isocyanates are highly reactive chemicals typically found in the hardener of two-part polyurethane paints (such as Cameleon's Camtect AU660) and primers. Isocyanates are present in two forms, monomer and pre-polymer. The isocyanate monomer content is frequently indicated in Material Safety Data Sheets (MSDS), but this is only a small part of the total un-reacted isocyanate present. Both forms of un-reacted isocyanate are a risk to health when they are released into the air during paint or primer spraying.

Breathing un-reacted airborne isocyanate can cause coughing, chest tightness, fever, fatigue and sensitization. Many cases of isocyanate-related sensitization have occurred in Australia. Once sensitized, further exposure to even very small amounts of isocyanate will cause distressing asthma-like reactions. The reaction may occur immediately or several hours after exposure. One exposure to a high airborne concentration or several exposures to lower concentrations may result in sensitization. There is no proven method for predicting whether any particular person will become sensitized if exposed to Isocyanates.

Direct skin contact with isocyanates may cause rashes, blistering and reddening of the skin. Repeated skin contact may cause skin sensitization.

Eye exposure to airborne isocyanates can cause eye irritation and temporary blurred vision. Direct contact with the eye may cause damage to the cornea.

SPRAYING ISOCYANATE CONTAINING POLYURETHANES

All spraying of isocyanate paints must be done in a commercial or engineered paint booth, or one that is acceptable to the local authorities. The painter must wear an air-supplied respirator.

SPRAYING ISOCYANATE CONTAINING PRIMERS

Although primers contain less isocyanate than paints, they must be applied in a paint booth unless there is a separate shop area which meets the following criteria: The shop area must be separated from the rest of the shop by a barrier or screen.

• The shop area must be equipped with an explosion proof ventilation system.
• The barrier or screen and the ventilation system must cause air to move from adjoining areas into the priming area. This will prevent airborne isocyanates from entering areas where workers are not protected by air-supplied respirators.
• The person who applies the primer must wear an air-supplied respirator. Even short duration priming tasks release unacceptably high levels of airborne isocyanate. Low-pressure spray guns release less airborne paint, but levels are still high enough that only air-supplied respirators provide sufficient protection.

PAINT MIXING AND CLEANING

Paint mixing areas must have sufficient ventilation to prevent the build-up of airborne solvent. There is not enough un-reacted isocyanate released during mixing to require the wearing of air-supplied respirators; however, a face shield should be worn where there is a risk of splashing paint into the eyes. Gloves should be worn to prevent skin contact. A cartridge-type respirator with organic vapour cartridges may be worn to reduce the amount of paint solvent breathed.

While cleaning spray guns by passing solvent through the gun under pressure, air supplied respirators must be worn since un-reacted isocyanate may be released into the work environment.

PERSONAL HYGIENE

The following advice should be heeded by all individuals when handling or using any paints that may contain isocyanates, to minimize the risk of sensitization, irritation or other health problems:

1. Individuals with a known skin sensitivity, existing dermatitis or dermal condition, or existing respiratory condition such as asthma, should not use or apply isocyanate containing paints unless medical permission has been sought.
2. Food and drink should never be consumed, stored, or prepared in areas where paint or thinners are stored or applied. In case of accidental poisoning by ingestion SEEK MEDICAL ATTENTION IMMEDIATELY.
3. Do not smoke whilst using paints or thinners.
4. Remove protective clothing and wash hands before meals or using toilet facilities.
5. Always use a barrier cream on exposed skin if protective clothing such as full sleeved overalls is impractical.
6. Upon removal of barrier creams at the end of work, application of moisturizing cream is recommended to re-fat the skin.
7. Do not expose cuts or abrasions to paints or thinners – this will provide chemicals a direct entry into the blood stream.
8. NEVER wash hands or any other skin surface that has been exposed to contact by paint with thinners or solvents. ALWAYS use soap and water to clean up.

PERSONAL PROTECTIVE EQUIPMENT

The following minimum Protective Equipment should be used whenever applying or using paints containing isocyanates:

Respiratory Protection
Workers must always wear air-supplied respirators when spraying paints and primers containing isocyanates. Other types of respirators do not provide adequate protection for workers spraying isocyanate paints and primers.
Air-supplied respirators approved by the United States National Institute for Occupational Safety and Health (NIOSH) as type C constant flow or pressure demand are generally accepted as being the most appropriate.
Breathing air for the painter’s air-supplied respirator must be clean. A non-oil type electrical compressor specifically designed for providing breathing air is the best choice. Compressed shop air may be used if filters are provided to remove water, oil and the breakdown products of oil. The compressor must be kept in good repair. Overheating of the compressor must be prevented so that carbon monoxide will not be produced. Only clean air can be used to feed the compressor. The source of the air must be distant from vehicle exhaust to avoid unacceptable carbon monoxide levels in the air breathed by the painter.
The breathing air must be supplied to respirators with tight fitting face-pieces at a rate of at least 115 litres per minute (4 cubic feet per minute), and of at least 170 litres per minute (6cfm) to respirators with loose fitting face-pieces. The air supply rate should not exceed 425 litres per minute (15cfm).
The airline feeding the spray gun may be split to also feed the supplied-air respirator as long as the air is filtered in the prescribed manner and supplied at the prescribed flow rate.
 

Solvent Impermeable Gloves

Always use solvent impermeable gloves to prevent skin contact with paints and thinners. Gloves should be washed free of contamination and dried before removal to reduce the risk of accidental skin contact during the removal process.

Overalls

Where possible wear full sleeved protective overalls, but where this is impractical then sensible working clothes that cover as much skin surface as possible should be worn. Cover all exposed skin surface with a good quality barrier cream to minimize the risk of exposure. If clothing should become soaked with paint or thinners, then remove immediately, taking care to avoid contact with skin. Thoroughly wash soiled clothing with soap and water before re-use.

Barrier Creams

Barrier creams should be used as a complement to protective clothing, and should be applied to all skin that might potentially be exposed to paints or thinners. Always remember, barrier creams are of limited use and should not be regarded as substitutes for good personal hygiene or as a replacement for solvent impermeable gloves.

Always re-apply barrier creams after washing skin.

In the event that paints or thinners are splashed onto skin, then remove immediately with soap and water. Remember, NEVER use solvents or thinners to remove paint from skin.

Face Masks

When mixing or preparing paints, eyes are particularly vulnerable to exposure by splashing, so where possible always wear a full face respirator. Where this is impossible or impractical, then protective eyewear must be worn.

If paint or thinners are splashed in the eyes then immediately irrigate with copious quantities of water for at least 15 minutes, ensuring that the eyelids are held open. Remove contaminated clothing and seek immediate medical advice.

Where paints are applied by brush, all that is normally required is either a face shield or protective eyewear. However, if signs of narcosis are felt, then a protective mask should be used. Dust masks are NOT SUITABLE protection against organic vapours.

Always store protective masks in sealed containers away from potential exposure to organic vapours. Once exposed to the atmosphere activated charcoal filters continue to absorb organic vapours and will have a reduced life expectancy if left exposed to fumes.

VENTILATION

Always ensure adequate ventilation whilst using to prevent the build up of fumes and vapours. Organic vapours are heavier than air and will accumulate in low lying areas, and this can be especially dangerous in confined spaces such as tanks or small rooms. If application is likely to lead to exposure to fumes in a confined area, then an air fed respirator must be worn at all times.

Dizziness, drunkenness, headache and nausea are all symptoms of exposure to solvent fumes. In the event of overexposure to solvent fumes leading to collapse, remove the individual to fresh air, ensuring your own safety. Remove any contaminated clothing and allow the person to rest comfortably on their side until fully recovered. In extreme circumstances, if the patient ceases breathing or is unconscious seek IMMEDIATE MEDICAL ASSISTANCE. Artificial respiration or CPR may be required.

Never use solvent based paints or thinners in proximity to sources of ignition or open flame. Solvent vapours can travel along the surface of the ground and flash back once ignited. They can flow down drains and ducts and affect people working in other areas that may not be protected.

FIRE & EXPLOSION

Once opened, paint and thinner containers release solvent vapours. The flash point of the paint or thinner is the lowest temperature that the product will give off sufficient vapour to form an inflammable mixture with air. If the flash point is lower than or close to the ambient air temperature there is a risk of fire or explosion. It requires only a spark or open flame to ignite inflammable vapours.

If the flash point is higher than the ambient temperature than the risk is significantly reduced. However, it is good work practice to disallow the presence of naked flames, matches, lighters, cigarettes in areas where flammable goods are used or stored. Precautions should be taken against static discharges and the location of non flame-proof electrical appliances.

Should a fire involving paint or thinners occur then:

1. DO NOT use water to attempt to extinguish. Most solvents float on water and this may spread the fire.
2. DO use a dry chemical, foam or CO₂ Extinguisher.
3. Protect yourself from fumes with breathing Apparatus.

Chemical fires are prone to emitting toxic gases ranging from CO₂ to Ammonia. Avoid breathing in smoke and fumes from fires unless suitably protected.

Always warn people down-wind of chemical fires to evacuate immediately and always seek immediate assistance from your local emergency services.

Solvent fires can spread extremely quickly. DO NOT put yourself or others at risk.

SPILLS

Should a spillage of paints or thinners occur the following procedure should be followed: (If the spillage is of a major nature then the relevant local authority and the fire service should be notified immediately).

1. Do not allow spilt material to enter drains or run off into waterways
2. Absorb spilled material with sand, earth, or other inert absorbent material. DO NOT use sawdust or paper.
3. Collect and seal in properly labelled drums for subsequent disposal in an approved facility.
4. Ventilate area to remove fumes.