Hazards of surface coatings

The major constituents of most paints can be grouped into four general categories:

  1. Resins
  2. Pigments
  3. Solvents
  4. Additives

Substances can enter the body through inhalation, absorption through the skin, or ingestion, with the most common route being inhalation. There is a risk of chemicals entering the body during mixing, application and/or clean up when using the paint.

Spray application presents the greatest hazard as the applicator is not just exposed to the highly volatile portion of the paint (solvents) but also to the paint mist.

What are the hazards?

  1. Resins:
    Resins themselves are not classified as toxic, however, it is possible for some resins to be asthma causing agents and induce inflammation of the mucous membranes and nose.

    Some also react with the moist tissues of the respiratory system and eyes, causing irritation, or can be very irritating to the skin.

    Although there are a lot of misconceptions about isocyanates, it is important to understand the main health issues and these are addressed under Polyurethane Paints and Lacquers.

    The typical effects of overexposure to isocyanates include chills, fever, flu like symptoms and tightness of the chest.

    Epoxies, polyamines and polyamides have been known to cause dermatitis. When skin contact does occur, wash thoroughly with lukewarm water and soap.

  2. Pigments:
    Lead and Zinc/Lead Chromates: the toxic effects of these are well documented. Lead poisoning symptoms include general weakness, loss of appetite, inability to sleep, irritability, pains in the muscles, joints and abdomen, mental retardation, anaemia, sterility, central nervous system disorders and reproductive effects. Zinc/Lead Chromates have been implicated in lung cancer of workers handling these pigments.

    Pigments in the finished paint are locked up by encapsulation in the resinous binder, however, sanding creates dusts in which pigments are more bio-available.

  3. Solvents:
    Solvents cause headaches, drowsiness and unconsciousness, irritation to the skin, eyes and respiratory tract, and central nervous system depression with similar symptoms to drunkenness. People can become addicted to some of these solvents and drinking alcohol during the day may increase the toxic risks of these solvents.

    Cleaning the hands in solvents such as turpentine will de-fat the skin and can cause dermatitis. Repeated exposure may result in chromic dermatitis.

    Most solvents used in paints are highly flammable so care needs to be taken that there are no sources of ignition available to the solvent or to solvent/air mixtures.

    Empty drums contain residues of solvents, which can be more dangerous than full drums, as the danger of explosion is greater.

  4. Additives:
    Additives may irritate the eyes, skin and respiratory organs.

The spray mists of paint
Whatever the brand or chemical nature of the paint, the spray mist of that paint will contain resins, pigments, solvents and additives. The spray applicator must ensure that the spray mist is not inhaled, and that suitable precautions are taken so it does not get onto skin or into eyes.