Isocyanates are a class of highly reactive, powerful compounds that react with alcohol-based compounds to produce polyurethane polymers used in certain solvent-based and water-based paints. Basically, they are chemicals that help make paint stick and that makes it possible for you to create such glossy, vibrant colors.

As OSHA points out, exposure to isocyanates can result in skin irritation, eye irritation, chest tightness and difficulty breathing. Isocyanates also have the potential for severe adverse effects to the respiratory tract in some individuals. If you spray polyurethane paints or foam, dermal exposure is a significant hazard, and you should also avoid breathing the aerosol droplet (mist), vapor or particulate. 

After ensuring that your painting booth or spray area is well-ventilated to help reduce airborne exposure to hazardous chemicals, you should use proper personal protective equipment (PPE) as determined by your employer, which may include eye protection, skin protection (gloves and coveralls) and a selection of appropriate respiratory protection. The following PPE is specific for the United States; you should check what PPE may be appropriate given your country’s regulations.

Respiratory Protection Options

Reusable respirators (also referred to as elastomeric respirators) are the most common type of respiratory protection used in painting applications. The 3M™ Ultimate FX Full Facepiece Reusable Respirator, FF-400 Series is a comfortable solution for painters looking for a full facepiece respirator. It incorporates a passive speaking diaphragm that can make it easier to communicate and a 3M™ Cool Flow™ Valve that can help make breathing easier. 

You can use this reusable respirator with 3M particulate filters, gas/vapor cartridges and even with supplied air systems, making it very versatile. 3M's lines of filters and cartridges are NIOSH-approved and can be chosen for protection against isocyanates. In addition to the FF-400 facepiece, these filters and cartridges will also work with 3M™ Half and Full Facepieces 6000 and 7000 series products.

The 3M™ Versaflo™ TR-800 Powered Air Purifying Respirator (PAPR) is helping set a new standard in intrinsically safe respiratory protection. Featuring our TR-800-PSK with Intrinsically Safe motor/blower, this kit includes all the components for immediate use. The kit includes a helmet, IS battery and charger, breathing tube and covers, combination organic vapor and high-efficiency filter cartridge and accessories for proper cleaning and storage. 

This innovative new PAPR is designed to incorporate ergonomic styling and long battery life. The PAPR design provides more freedom than supplied air systems because the painter is not tethered to an air hose, allowing the painter to move about the booth easily as well as leave and return to the booth or area without removing the equipment. 

The TR-800 system features multiple speeds, audible and visual alarms and the ability to work with a wide variety of cartridges. This type of protection can help you with paints and coatings, including flammable and combustible ones that may contain isocyanates.

Don’t forget that the use of NIOSH-certified respirators in workplace environments must be accompanied by a full respiratory protection program as specified in OSHA 29 CFR 1910.134. Your respiratory protection program should include certain important parts, including written standard operating procedures, medical evaluations, fit testing (where applicable), user training, respirator cleaning and maintenance, and cartridge/filter change schedule for air purifying respirators. And remember, when selecting and using a respirator, it is important to read and follow all User Instructions carefully. Engaging your local 3M safety specialist is a great option if you need help with any of the above. 


Protective Apparel Considerations for Coveralls 

When it comes to dermal exposure to isocyanates and other chemicals found in paints and coatings, you need adequate skin protection and the most common form of that is full body coveralls. Are your current coveralls providing adequate protection from things like isocyanates and other particulates found in paintings and coatings? 

The 3M™ Protective Coverall 4540+  is a versatile protective coverall. It offers a good barrier to particles and liquid splashes from painting applications. It also features a breathable back panel for comfort and a fully sealable storm flap over the zipper for full-suit protection. These coveralls also feature extra room in the arms and legs, two-way zippers for added on-off convenience as well as seamless shoulders and sleeve tops for extra protection. In addition, 4540+ product series offers a collared option for situations where a hood is not required. Advanced, breathable and lightweight materials help reduce heat build-up and promote comfortable wear—a growing requirement for painters.

If you use paint with isocyanates, make sure you are protected. Find the right PPE that will help protect you from dermal and respiratory exposure. Please note that the PPE discussed above is specific for the United States and you should check what PPE may be appropriate given the regulations in your country.