Encapsulants: A Technique to Control Lead Paint Hazards

Lead-based paint is a health hazard to children and adults because the dust chips and fumes can be ingested or inhaled. In 1978, the U.S. Consumer Product Safety Commission limited the amount of lead allowed in paint. Any surface painted before that year has the potential to be a lead hazard.

Lead paint hazards can be controlled in several ways: Doors and windows containing lead paint can be replaced, paint can be removed utilizing a method that minimizes dust and fumes, or surfaces can be covered with hard materials, such as sheet rock or paneling.

The use of encapsulants is also available as a technique to prevent exposure to lead-based paint. The instructions and guidance of the manufacturers must be followed to test, prepare and apply these products.

What are encapsulants?

  • Encapsulants are materials that are applied over lead-based paint to seal the paint to a surface and prevent the release of paint chips or dust. The material may be either a liquid or an adhesive. Encapsulation provides a barrier between the paint and the environment. Conventional paint is NOT an encapsulant.

How do encapsulants work?

  • Encapsulants cover lead paint so that the paint cannot produce dangerous dust, and humans cannot come into contact with it.
  • Encapsulants work best on clean, dry and solid surfaces.
  • Encapsulants cannot be used on the following:
    • Surfaces that are walked on;
    • Surfaces that rub together;
    • Surfaces that are badly deteriorated.

Are encapsulants all the same?

There are three types of encapsulants:

  • There are polymers (chemical compounds) that form a flexible, resilient membrane. They are applied with a brush, roller, or airless spray gun.
  • There are epoxy or polyurethane polymers that form a membrane with a hard, but flexible, surface. They are applied with a brush, roller, or airless spray gun.
  • There are cement-like materials with polymers that cure to form a thick coating. They are generally applied with a trowel.

How do I decide to use an encapsulant?

There are several points to consider before using an encapsulant:

  • You must follow the manufacturer's guidelines for testing, preparation and application. The person performing the on-site testing to determine appropriate surfaces for encapsulants must meet standards set by the manufacturer.
  • Although encapsulants offer permanent protection from lead-based paint, they must be periodically inspected and repaired, if damaged.
  • You must use different encapsulants in different situations. Follow the manufacturers' recommendations and instructions.
  • When covering lead paint, some thicker encapsulants may also destroy architectural detail, especially on moldings.
  • Encapsulants must be applied by a person who has met the manufacturers' specifications. Contact the manufacturer for specific criteria.
  • The only permanent solutions that do not require periodic maintenance and inspection include replacement of doors and windows, or complete removal of lead paint.

What surfaces are suitable for encapsulation?

The suitable surfaces should have the following characteristics:

  • Dry and free of grime, dirt, dust, grease, charring, smoke residue (especially cigarette or hydrocarbon), mildew, or other contaminants. Water-based encapsulants will tolerate damp, but not wet, surfaces without losing their most important properties.
  • Free of water leaks.
  • Non-glossy. High-gloss surfaces can be deglossed with chemical deglossers or wet sanding before encapsulation.
  • In architecturally sound condition.
  • Undamaged (i.e., no holes or large cracks in walls). Damaged areas must be repaired prior to encapsulation.

What surfaces are not suitable for encapsulation?

  • "Friction" and high profile (i.e., protruding window sills) surfaces are not suitable, regardless of their condition. Friction surfaces include window jambs; glides; headers; some stops and parting beads; inside, close-fitting door jambs and stops; floors; stair treads; and thresholds. Cabinets with friction surfaces, such as drawers and cabinet doors, should be examined before encapsulation. Where friction exists, planing or smoothing of the surfaces is recommended.

What are the advantages of using encapsulants?

  • Residents may not need to leave the building during surface preparation and application if dust is not released. Occupants should never be in the immediate work area (i.e., same room) during application.
  • If a surface with lead paint is intact, it may be possible to apply an encapsulant without surface preparation.
  • Use of encapsulants may be less costly, more time-saving and safer than other methods.

What are the disadvantages of using encapsulants?

  • There is limited experience or information on long-term performance of encapsulants.
  • Encapsulants cannot be used on surfaces that experience abrasion or constant friction.
  • Encapsulants may prematurely wear on a surface that experiences repeated impact, such as door stops, window stops and stair treads.
  • Encapsulants may peel off improperly prepared surfaces that have old undercoats of paint.
  • Encapsulants must be tested on-site before application.
  • Encapsulants require periodic inspection for repair or maintenance.
  • Water from roof leaks or broken pipes may damage encapsulants.
  • Encapsulants must be applied when the air temperature and relative humidity are within specified ranges.

For more information, contact your local health department, or call the New York State Department of Health Center for Environmental Health at 518-402-7600.