WHAT'S REALLY IN A CAN OF PAINT?

         Paint is a creation of man used from the beginning of recorded history -- from the caves of Lascaux in France to the ceiling of the Sistine Chapel, on the figureheads of the Spanish ships which founded the New World , to the decorative symbols on teepees of Native Americans. It is used for decoration, for communication, as a preservative and as a maintenance tool. Today, paint has evolved into the protector, preserver and beautifier of home, workplace, public spaces and even houses of worship.

A thin film of paint -- a few thousandths of an inch thick -- protects, seals, hides, and decorates. Simply put, paint offers long term protection at a very moderate price. It keeps existing structures from deteriorating and, in so doing, preserves natural resources such as trees, water, and a variety of energy sources. To further appreciate the merits of paint, it is important to understand what actually goes into the can.

Paint is a simple mixture of ingredients including pigments, a binder and a diluent, or thinner (in latex paint is it water; in solvent paints, it is a petroleum solvent).

Today's pigments, not unlike the mud, blood and chalk used centuries ago, provide the texture, color and hiding properties of paint. The pigments, usually in the form of dry powder, can be organic (containing carbon), inorganic (no carbon), synthetic or naturally-occurring. Today, with the utmost concern for consumer safety, architectural coatings are formulated to be as safe as possible by carefully selecting pigments. No longer in uses in consumer paints are pigments which were found to pose potential health hazards because they contained chromates, lead, soluble barium, or asbestos.

Titanium dioxide is the primary pigment ingredient that provides hiding in light color paints. While any powder, even baby powder, can pose a health hazard if inhaled in high concentrations, titanium dioxide which is also used in cosmetics, soaps and certain food products, when used in a paint film is not respirable and poses no risk to the user. Other inert pigments include calcium carbonate (limestone), talc, clay, sand (silica). All of these are naturally occurring materials that are tightly bound in the paint film and contribute various properties like gloss control, flow, and film build. Iron oxides are inorganic color pigments, chemically akin to rust on metal, that are used to produce reds and yellows.

The binder portion of architectural coatings consist of synthetic and natural resins which start out as liquids but dry to form tough durable films. The properties of the binder largely determine the properties of the paint film. In waterborne coatings the binder is usually a latex emulsion composed of vinyl and/or acrylic copolymers. In solventborne coatings the binder is usually an alkyd, which is a natural drying oil modified chemically to be especially tough and long-lasting.

As most people know, today's latex emulsion paints are thinned with water and represent the ultimate in safety and ease of use. Solvent-based or oil paints are thinned with petroleum solvent which make them less convenient and require more care to be used safely. Over the years, use of solventborne paint has diminished because of concern over volatile organic compounds (VOCs). However, solventborne paints still play an important role today because of their unique durability and adhesion properties.

Before using any coating carefully read and follow label instructions.

Other ingredients in paint, called "additives," impart a variety of properties including flow, stability, drying, defoaming, mildew resistance and viscosity.

 ADDITIVES

Some additives caused health concerns in the past and have been removed or greatly reduced in modern coatings.

Formaldehyde is no longer added to paints or resins. At one time, it served as a biocide to prevent bacterial degradation of the paint. It was replaced over the last decade with ingredients commonly used in household products and cosmetics.

Mercury which was added to coatings as a biocide after World War II (when it was also used in medicines) was eliminated from all paints by Benjamin Moore in 1970. By 1991 mercury in paint was regulated by EPA and was removed by all manufacturers.

Lead was eliminated from consumer products by Benjamin Moore more than 20 years ago and by the industry at large over ten years ago. Lead was used in many forms over the years and provided hiding, color, drying, and corrosion resistance in architectural and industrial maintenance coatings. By the 1970's lead use was limited to drying, corrosion resistance and some industrial maintenance colors.

Other additives:

Coalescents (a.k.a. film forming aids) are solvents used in waterborne coatings which help fuse, or coalesce, latex particles in latex emulsion paints during the drying process. They make possible better paint films by permitting the use of harder resins in the coatings formulation. These harder resins result in interior paints that are scrub resistant and durable.

Anti-skinning agents, used only in solventborne coatings, prevent undesirable surface drying, or skinning, in the container during storage and shipment.

Pigment suspending aids, dispersants, and surfactants are present in most paints in very small quantities. They impart stability and promote shelf-life.

Viscosity and flow enhancers, provide superior application properties, as their description implies. They are needed to achieve the best possible hiding and film appearance.

While solventborne coatings use is on the decline, especially in the consumer sector, these paints still provide important, unique properties not always available in waterborne coatings. Properties at which solventborne coatings excel include:

Rust-inhibitive and other special primers, such as stainblockers.

Stains, such as wood stain for furniture refinishing and exterior semi-transparent finishes.

Varnishes, such as clear finishes for interior use and exterior varnishes, such as marine.

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