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Lead Abatement or Encapsulation?
Conventional paint will only temporarily seal lead into a surface.
By Rachel Hofmeister
Lead-based paint has become the buzzword among property owners, cleaning contractors
and facility managers responsible for the health and safety of a building's occupants or
tenants. Lead is a serious health threat in all its various forms, but it is particularly
dangerous in lead-based paint to children under the age of 6.
Lead-based paint chips have a sweet taste -- which comes from lead chromate -- that
tastes similar to honey. This taste encourages children to continue eating them,
ultimately
causing lead poisoning. While lead chips constitute a serious health hazard, one of the
primary causes of lead poisoning comes from lead dust.
Lead is a cumulative poison that, once ingested, travels through the bloodstream and
attacks vital organs, causing a variety of health problems, including impaired motor
functions, hyperactivity, retardation, convulsions, and learning and behavioral problems.
While the occurrence of lead poisoning in adults is not as frequent or severe as it is
with
children, lead-abatement workers and building occupants can be at great risk of being
poisoned if renovations and deleading are done without proper worker protection, waste
disposal and cleanup.
When a lead-based painted surface is scraped or sanded, toxic lead dust is released into
the
air and can remain airborne indefinitely in a structure, endangering future occupants.
Unless the proper respiratory protection is used, lead dust in the air will elevate the
level
of lead in a worker's bloodstream.
Until recently, the incidence of lead poisoning due to improper abatement was more likely
due to the fact that the only means available for displacing lead-based paint was complete
and total removal. Traditional lead abatement by removal is a costly method that requires
occupants to vacate the facility, full containment measures to be installed (as required
by
OSHA), workers to wear complete bunker gear, and all waste to be considered hazardous
and disposed of at a hazardous waste facility.
Billion-Dollar Cleanup
According to the U.S. Environmental Protection Agency (EPA) extensive abatement
procedures would have to be performed in 57 million residential units, at a cost of
$10,000
per unit to completely abate lead hazards nationwide. This $570 billion estimate accounts
only for residential structures and does not reflect the EPA's estimate of another $500
billion for the cleanup of commercial facilities.
Within the past five years, encapsulation as an abatement technique has surfaced and been
welcomed as a cost-effective alternative solution. U.S. Department of Housing and Urban
Development (HUD) guidelines define encapsulation as "the process that makes
lead-based paint inaccessible by providing a barrier between the lead-based paint and the
environment."
Although a wide range of products are marketed as encapsulants -- everything from
epoxies to cement -- most often, encapsulants are liquid coatings comprised of a
combination of materials, including elastomeric polymers and thermoplastice resins (which
gives them the characteristics of flexibility and high-impact resistance). Applied in a
fashion similar to paint, encapsulation as an abatement method has none of the
disadvantages that come from releasing lead into the environment through traditional
abatement procedures.
The majority of encapsulants are water-based, non-toxic formulations that can be cleaned
up with soap and warm water. In most circumstances, building users can return to the
premises shortly after the encapsulant has been applied.
Encapsulation is a solution limited to applications where the paint is intact (or mostly
intact). It is not a panacea for the abatement of lead-based paint, but an alternative --
where applicable -- to the expense and danger of scraping or sanding.
`Paint' It On
Encapsulants can be applied with a brush, roller or airless sprayer, and don't require
specialized training or painting experience. However, direct your crew to follow the
manufacturer's recommendations regarding surface preparation, film thickness and
environmental conditions. While the methods of application and final appearance resemble
paint to the untrained eye, encapsulants are designed with performance capabilities
necessary to encapsulate lead, capabilities that average paint doesn't have.
For example, most water-based encapsulants should be applied when the temperature is
above 50 degrees Fahrenheit; humidity levels should be approximately 85 percent. These
recommendations are similar to the application of latex paint.
However, while paint is applied in a thin layer and dries to a thickness of approximately
1
dry mil (1 millionth of an inch), encapsulants are formulated to dry to a thickness of 7
to
20 dry mils to prevent lead from leaching through the coating and gathering on the surface
as dust.
Although hotly debated in the scientific community, the tendency for lead to migrate has
been demonstrated in laboratory testing and is one of the main reasons that coatings
specifically formulated as encapsulants were designed.
Testing the Surface
The surface to be encapsulated must be prepared by washing it with a trisodium phosphate
(TPS) solution, a liquid cleaner designed to remove surface debris, including dust,
grease,
oil, mildew, calcimine, wax and soap. For areas deemed inappropriate for encapsulation
(friction surfaces such as window sashes, door jambs and floors) or surfaces that are
chipping, peeling or otherwise deteriorated, a state-licensed deleader must perform the
necessary lead abatement.
Encapsulation is permitted in every U.S. state. However, because there are no federal
regulations governing lead-abatement procedures, individual states have had to adopt their
own lead policies concerning lead-abatement and encapsulation.
Massachusetts was the first state to develop its own lead-abatement policies and has the
most comprehensive lead legislation in place, including a register of certified
encapsulant
products.
Lead Legislation
Massachusetts established requirements for lead-based paint encapsulants in November
1994. The state invited encapsulant manufacturers to submit their products to an
independent laboratory for testing according to state-established criteria.
Their products were required to meet standards in 13 categories, including the ability to
withstand a direct blow of 80 pounds per square inch (psi), absorb 1,000 scrubs with a
heavy scouring pad under wet and dry conditions with only an 80 percent loss in film
thickness, and stretch as much as 30 percent without breaking. Massachusetts tested
nearly 20 products and found several that met the state's performance requirements.
In Massachusetts, if a home is found to have lead, a licensed lead inspector will include
with the inspection (at the owner's request) a surface assessment, which is performed to
determine if the existing paint is suitable for encapsulation.
The inspector uses a number of tests, including a visual assessment, the application of
pressure-sensitive tape to gauge adhesion of the existing paint, and application of a
patch
test of sample encapsulant to verify whether the surface condition is compatible with
encapsulation. If encapsulation can be used, the homeowner or their agent must review the
state's lead-training educational materials (which includes a free encapsulant video) and
complete a one-page, take-home test.
Other states, such as Connecticut, New Hampshire, Ohio, New Jersey, Minnesota and
Pennsylvania, have begun to develop their own policies, and are expected to incorporate
elements of the Massachusetts protocol for liquid encapsulants into their lead
legislation.
Many states insist on the use of only licensed professionals to perform encapsulation, but
the nature of this technology suggests that eventually it will become a way for
individuals
and companies who do not specialize in traditional lead abatement to make a property
lead-safe.
ASTM Standards
In addition to new lead policies in the individual states, there has been some recent
progress at the national level as well. The American Society for Testing and Materials
(ASTM) -- the organization charged by HUD and EPA to develop minimum standards for
encapsulants -- published in August 1995 the Provisional Standard Specification for
Liquid Coating Encapsulation Products for Leaded Paint in Buildings. After three years of
evaluation, ASTM has provided a list of qualifications that HUD and EPA can use to
approve liquid encapsulants.
Although it is expected that the ASTM standard will form the basis for encapsulation
guidelines included in eventual national lead legislation, what is important now is that a
standard exists that defines what criteria a product must meet to be considered a true
liquid encapsulant.
This is significant because some manufacturers have recently attempted to promote
commercial paint for use as an encapsulant. Conventional paint is not an encapsulant and
Currently there is no paint being manufactured that could meet the specification criteria
established by ASTM for liquid encapsulants.
Conventional paint is, at best, a temporary measure to reduce the hazards of lead. HUD, in
its Guidelines for the Evaluation and Control of Lead-Based Paint in Housing, released in
late 1995, defined paint as an "interim control." Unlike abatement, which is
considered a
permanent solution to lead hazards, interim controls are only intended as temporary
measures to control exposure to lead.
Interim Controls
Interim controls include cleaning, repairing and repainting (with conventional paint)
lead-paint surfaces. These methods must be monitored, evaluated and maintained on a
regular basis by the property owner and a certified inspector.
ASTM evaluated products on 25 performance requirements and laboratory test
procedures. Some of these included: adhesion, the ability of an encapsulant to bond to the
substrate; dry abrasion resistance, the ability of a product to lose no less than 20
percent
of film thickness after 1,000 scrub cycles; water vapor transmission, the capability of a
product to not have water buildup underneath it; flexibility; paintability; and impact and
mildew resistance. A copy of ASTM's standards (which includes a listing of testing
methods and procedures) can be ordered from ASTM by calling (215) 299-5400.
Lead found in paint presents a serious health risk. Because abatement by removal has
many disadvantages, encapsulation is a solution that may work for you. Encapsulation is a
practical alternative -- when the surface is in good condition -- that can save time,
money,
labor and disposal costs.
Rachel Hofmeister is marketing coordinator for Fiberlock Technologies, Inc., a
manufacturer of specialty encapsulation products, in Cambridge, MA.
Copyright© 1995 National Trade Publications, Inc.
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