Appropriate Methods for Reducing Lead-Paint Hazards in Historic Housing
SharonC. Park, AIA and Douglas C. Hicks
Lead in Historic Paints
Lead-based paint, a toxic material, was widely used in North Americaon both the exteriors and interiors of buildings until well into the secondhalf of the twentieth century.
If a "historic" place is broadlydefined in terms of time as having attained an age of fifty years, thismeans that almost every historic house contains some lead-based paint.In its deteriorated form, it produces paint chips and lead-laden dust particlesthat are a known health hazard to both children and adults.
Children areparticularly at risk when they ingest lead paint dust through direct hand-to-mouthcontact and from toys or pacifiers. They are also at risk when they chewlead-painted surfaces in accessible locations. In addition to its presencein houses, leaded paint chips, lead dust, or lead-contaminated soil inplay areas can elevate a child's blood lead level to a degree that measuresto reduce and control the hazard should be undertaken (see Action LevelChart.
The premise of this Preservation Brief is that historic housing canbe made lead-safe for children without removing significant decorativefeatures and finishes, or architectural trimwork that may contribute tothe building's historic character.
Historic housing--encompassingprivate dwellings and all types of rental units--is necessarily the focusof this Brief because federal and state laws primarily address the hazardsof lead and lead-based paint in housing and day-care centers to protectthe health of children under six years of age. Rarely are there mandatedrequirements for the removal of lead-based paint from non-residential buildings.
Ideally, most owners and managers should understand the health hazardscreated by lead-based paint and voluntarily control these hazards to protectyoung children. A stricter approach has been taken by some state and federalfunding programs which have compliance requirements for identifying theproblem, notifying tenants, and, in some cases, remedying lead hazardsin housing (see Lead-based PaintLegislation). With new rules being written,and new products and approaches being developed, it is often difficultto find systematic and balanced methodologies for dealing with lead-basedpaint in historic properties.
This Preservation Brief is intended to serve as an introduction to thecomplex issue of historic lead-based paint and its management. It explainshow to plan and implement lead-hazard control measures to strike a balancebetween preserving a historic building's significant materials and featuresand protecting human health and safety, as well as the environment. Itis not meant to be a "how-to guide" for undertaking the work.Such a short-cut approach could easily result in creating a greater healthrisk, if proper precautions were not taken.
Home renovators and constructionworkers should be aware that serious health problems can be caused by cominginto contact with lead. For this reason, there are also laws to protectworkers on the job site (see Worker Safety). Controlling the amountof waste containing lead-based paint residue will also reduce the impacton the environment. All of these considerations must be weighed againstthe goal of providing housing that is safe for children.
Lead compounds were an important component of many historic paints.Lead, in the forms of lead carbonate and lead oxides, had excellent adhesion,drying, and covering abilities. White lead, linseed oil, and inorganicpigments were the basic components for paint in the 18th, 19th, and early20th centuries.
Lead-based paint was used extensively on wooden exteriorsand interior trimwork, window sash, window frames, baseboards, wainscoting,doors, frames, and high gloss wall surfaces such as those found in kitchensand bathrooms. Almost all painted metals were primed with red lead or paintedwith lead-based paints. Even milk (casein) and water-based paints (distemperand calcimines) could contain some lead, usually in the form of hidingagents or pigments. Varnishes sometimes contained lead. Lead compoundswere also used as driers in paint and window glazing putty.
In 1978, the use of lead-based paint in residential housing was bannedby the federal government. Because the hazards have been known for sometime, many lead components of paint were replaced by titanium and otherless toxic elements earlier in the 20th century. Since houses are periodicallyrepainted, the most recent layer of paint will most likely not containlead, but the older layers underneath probably will. Therefore, the onlyway to accurately determine the amount of lead present in older paint isto have it analyzed.
It is important that owners of historic properties be aware that layersof older paint can reveal a great deal about the history of a buildingand that paint chronology is often used to date alterations or to documentdecorative period colors.
Highly significant decorativefinishes, such as graining, marbleizing, stenciling, polychrome decoration,and murals should be evaluated by a painting conservator to develop theappropriate preservation treatment that will stabilize the paint and eliminatethe need to remove it. If such finishes must be removed in the processof controlling lead hazards, then research, paint analysis, and documentationare advisable as a record for future research and treatment.
Typical health department guidelines call for removing as much of thesurfaces that contain lead-based paint as possible. This results in extensiveloss or modification of architectural features and finishes and is notappropriate for most historic properties.
A great number offederally-assisted housing programs are moving away from this approachas too expensive and too dangerous to the immediate work environment. Apreferred approach, consistent with The Secretary of the Interior's Standardsfor the Treatment of Historic Properties, calls for removing, controlling,or managing the hazards rather than wholesale-or even partial-removal ofthe historic features and finishes. This is generally achievedthrough careful cleaning and treatment of deteriorating paint, frictionsurfaces, surfaces accessible to young children, and lead in soil. Lead-based paint that it not causing a hazard is thus permittedto remain, and, in consequence, the amount of historic finishes, featuresand trimwork removed from a property is minimized.
Because the hazard of lead poisoning is tied to the risk of ingestinglead, careful planning can help to determine how much risk is present andhow best to allocate available financial resources. An owner, with professionalassistance, can protect a historic resource and make it lead-safe usingthis three-step planning process:
I. Identify the historical significance of the building and architecturalcharacter of its features and finishes
The historical significance, integrity, and architectural characterof the building always need to be assessed before work is undertaken thatmight adversely affect them. An owner may need to enlist the help of apreservation architect, building conservator or historian. The State HistoricPreservation Office (SHPO) may be able to provide a list of knowledgeablepreservation professionals who could assist with this evaluation.
Features and finishes of a historic building that exhibit distinctivecharacteristics of an architectural style; represent work by specializedcraftsmen; or possess high artistic value should be identified so theycan be protected and preserved during treatment.
When it is absolutelynecessary to remove a significant architectural feature or finish-as notedin the first two priorities listed below-it should be replaced with a newfeature and finish that matches in design, detail, color, texture, and,in most cases, material.
Finally, features and finishes that characterize simple, vernacularbuildings should be retained and preserved; in the process of removinghazards, there are usually reasonable options for their protection. Wholesaleremoval of historic trim, and other seemingly less important historic material,undermines a building's overall character and integrity and, thus, is neverrecommended.
For each historic property, features will vary in significance. As partof a survey of each historic property, a list of prioritiesshould be made, in this order:
This hierarchy gives an owner a working guide for making decisions aboutappropriate methods of removing lead paint.
II. Undertake a risk assessment of interior and exterior surfaces todetermine hazards from lead and lead-based paint.
While it can be assumed that most historic housing contains lead-basedpaint, it cannot be assumed that it is causing a health risk and shouldbe removed. The purpose of a risk assessment is to determine, through testingand evaluation, where hazards from lead warrant remedial action.
Testing by a specialist can be done on paint, soil, or lead dust eitheron-site or in a laboratory using methods such as x-ray fluorescence (XRF)analyzers, chemicals, dust wipe tests, and atomic absorption spectroscopy.Risk assessments can be fairly low cost investigations of the location,condition, and severity of lead hazards found in house dust, soil, water,and deteriorating paint. Risk assessments will also address other sourcesof lead from hobbies, crockery, water, and the parents' work environment.
A public health office should be able to provide names of certified riskassessors, paint inspectors, and testing laboratories. These services arecritical when owners are seeking to implement measures to reduce suspectedlead hazards in housing, day-care centers, or when extensive rehabilitationsare planned.
The risk assessment should record:
It is important from a health standpoint that future tenants, painters,and construction workers know that lead-based paint is present, even undertreated surfaces, in order to take precautions when work is undertakenin areas that will generate lead dust. Whenever mitigation work is completed,it is important to have a clearance test using the dust wipe methodto ensure that lead-laden dust generated during the work does not remainat levels above those established by the Environmental Protection Agency(EPA) and the Department of Housing and Urban Development (HUD) (see ActionLevels Chart). A building file should be maintained and updated wheneverany additional lead hazard control work is completed.
Hazards should be removed, mitigated, or managed in the order of theirhealth threat, as identified in a risk assessment (with 1. the greatestrisk and 8. the least dangerous):
III. Evaluate options for hazard control in the context of historicpreservation standards.
The Secretary of the Interior's Standards for the Treatment of HistoricProperties-established principles used to evaluate work that may impactthe integrity and significance of National Register properties-can helpguide suitable health control methods.
The preservation standardscall for the protection of historic materials and historic character ofbuildings through stabilization, conservation, maintenance, and repair.The rehabilitation standards call for the repair of historic materials with replacement of a character-definingfeature appropriate only when its deterioration or damage is so extensivethat repair is infeasible. From a preservation standpoint, selecting ahazard control method that removes only the deteriorating paint,or that involves some degree of repair, is always preferable to the totalreplacement of a historic feature.
By tying the remedial work to the areas of risk, it is possible to limitthe amount of intrusive work on delicate or aging features of a buildingwithout jeopardizing the health and safety of the occupants. To make historichousing lead-safe, the gentlest method possible should be used to removethe offending substance-lead-laden dust, visible paint chips, lead in soil,or extensively deteriorated paint.
Overly aggressive abatement may damageor destroy much more historic material than is necessary to remove leadpaint, such as abrading historic surfaces. Another reason for targetingpaint removal is to limit the amount of lead dust on the work site. This,in turn, helps avoid expensive worker protection, cleanup, and disposalof larger amounts of hazardous waste.
Whenever extensive amounts of lead must be removed from a property,or when methods of removing toxic substances will impact the environment,it is extremely important that the owner be aware of the issues surroundingworker safety, environmental controls, and proper disposal. Appropriate architectural, engineering and environmental professionalsshould be consulted when lead hazard projects are complex.
Following are brief explanations of the two approaches for controllinglead hazards, once they have been identified as a risk. These controlsare recommended by the Department of Housing and Urban Development in Guidelinesfor the Evaluation and Control of Lead-Paint Hazards in Housing, andare summarized here to focus on the special considerations for historichousing:
Interim Controls: Short-term solutions include thoroughdust removal; thorough washdown and clean-up of exposed surfaces; paintfilm stabilization and repainting; covering of lead-contaminated soil;and making tenants aware of lead hazards. Interim controls require ongoingmaintenance and evaluation.
Hazard Abatement: Long-term solutions are defined as havingan expected life of 20 years or more, and involve permanent removal ofhazardous paint through chemicals, heat guns or controlled sanding/abrasivemethods; permanent removal of deteriorated painted features through replacement;the removal or permanent covering of contaminated soil; and the use ofenclosures (such as drywall) to isolate painted surfaces. The use of specializedelastomeric encapsulant paints and coatings can be considered as permanentcontainment of lead-based paint if they receive a 20-year manufacturer'swarranty or are approved by a certified risk assessor. One should be awareof their advantages and drawbacks for use in historic housing.
Within the context of the historic preservation standards, the mostappropriate method will always be the least invasive. More invasive approachesare considered only under the special circumstances outlined in the three-stepprocess. An inverted triangle shows the greatest number ofresidential projects fall well within the "interim controls"section.
Most housing can be made safe for children using these sensitivetreatments, particularly if no renovation work is anticipated. Next, whereowners may have less control over the care and upkeep of housing and rentalunits, more aggressive means of removing hazards may be needed. Finally,large-scale projects to rehabilitate housing or convert non-residentialbuildings to housing may successfully incorporate "hazard abatement"as a part of the overall work.
In selecting appropriate methods for controlling lead hazards, it isimportant to refer to Step I. of the survey where architecturally significantfeatures and finishes are identified and need to be preserved. Work activitieswill vary according to hazard abatement needs; for example, while an interimcontrol would be used to stabilize paint on most trimwork, an accessiblewindow sill might need to be stripped prior to repainting. Since painton a window sill is usually not a significant finish, such work would beappropriate.
The method selected for removing or controlling the hazards has a directbearing on the type of worker protection as well as the type of disposalneeded, if waste is determined to be hazardous. Followingare examples of appropriate methods to use to control lead hazards withinan historic preservation context.
Historic Interiors (deteriorating paint and chewed surfaces).Whenever lead-based paint (or lead-free paint covering older painted surfaces)begins to peel, chip, craze, or otherwise comes loose, it should be removedto a sound substrate and the surface repainted. If children are presentand there is evidence of painted surfaces that have been chewed, such asa window sill, then these surfaces should be stripped to bare wood andrepainted. The removal of peeling, flaking, chalking, and deterioratingpaint may be of a small scale and undertaken by the owner, or may be extensiveenough to require a paint contractor. In either case, care must be takento avoid spreading lead dust throughout the dwelling unit. If the paintfailure is extensive and the dwelling unit requires more permanent hazardremoval, then an abatement contractor should be considered. Many statesare now requiring that this work be undertaken by specially trained andcertified workers.
If an owner undertakes interim controls, it would be advisable to receivespecialized training in handling lead-based paint. Such training emphasizesisolating the area, putting plastic sheeting down to catch debris, turningoff mechanical systems, taping registers closed, and taking precautionsto clean up prior to handling food. Work clothes should be washed separatelyfrom regular family laundry. The preferred method for removing flakingpaint is the wet sanding of surfaces because it is gentle to the substrate andcontrols lead dust. The key to reducing lead hazards while stabilizingflaking paint is to keep the surfaces slightly damp to avoid ingestinglead dust. Wet sanding uses special flexible sanding blocks or papers thatcan be rinsed in water or used along with a bottle mister. This methodwill generally not create enough debris to constitute hazardous waste.
Other methods for selectively removing more deteriorated paint in historichousing include controlled sanding, using low-temperature heat guns, orchemical strippers. Standard safety precautions and appropriate workerprotection should be used. Methods to avoid include uncontrolleddry abrasive methods, high heat removal (lead vaporizes at 1100 degrees F), uncontrolledwater blasting, and some chemicals considered carcinogenic (methylene chloride).When possible and practicable, painted elements, such as radiators, doors,shutters, or other easily removable items, can be taken to an off sitelocation for paint removal.
In most cases, when interior surfaces are repainted, good quality interiorlatex or oil/alkyd paints may be used. The paint and primer system mustbe compatible with the substrate, as well as any remaining, well-bonded,paint.
Encapsulant paints and coatings, developed to contain lead-based paint,rely on an adhesive bonding of the new paint through the layers of theexisting paint. The advantages of these special paint coatings is thatthey allow the historic substrate to remain in-place; reduce the amountof existing paint removed; can generally be applied without extensive workerprotection; and are a durable finish. (They cannot, however, be used onfriction surfaces.) The drawbacks include their ability to obscure carveddetails, unless thinly applied in several applications, and difficultyin future removal. If a specialized paint, such as an elastomeric encapsulantpaint, is considered, the manufacturer should be contacted for specificinstructions for its application. Unless these specialized paint systemsare warranted for 20 years, they are considered as less permanent interimcontrols.
Lead-dust on interior finishes. Maintaining and washingpainted surfaces is one of the most effective measures to prevent leadpoisoning. Houses kept in a clean condition, with paint film intact andtopcoated with lead-free paint or varnish, may not even pose a health risk.Dust wipe tests, which are sent to a laboratory for processing, can identifythe level of lead dust present on floors, window sills, and window troughs.If lead dust is above acceptable levels, then specially modified maintenanceprocedures can be undertaken to reduce it.
All paints deteriorate overtime, so maintenance must be ongoing to control fine lead dust. The periodicwashing of surfaces with a surfactant, such as tri-sodium phosphate (TSP)or its equivalent, loosens dirt and removes lead dust prior to a waterrinse and touch-up painting, if necessary. This interim treatment can beextremely beneficial in controlling lead dust that is posing a hazard.
Soil/landscape. Soil around building foundations may containa high level of lead from years of chalking and peeling exterior paint.This dirt can be brought indoors on shoes or by pets and small childrenif they play outside a house. Lead in the soil is generally found in anarrow band directly adjacent to the foundation. If the bare soil testshigh in lead (see Action Levels Chart), it should be replaced to a depthof several inches or covered with new sod or plantings. Care should betaken to protect historic plantings on the building site and, in particular,historic landscapes, while mitigation work is underway. Ifan area has become contaminated due to a variety of environmental conditions(for example, a smelter nearby or water tanks that have been sandblastedin the past), then an environmental specialist as well as a landscape preservationarchitect should be consulted on appropriate site protection and remedialtreatments. It is inappropriate to place hard surfaces, such as concreteor macadam, over historically designed landscaped areas, which is oftenthe recommendation of typical abatement guidelines.
Deteriorating paint on exteriors. Deteriorating exteriorpaint will settle onto window ledges and be blown into the dwelling, andwill also contaminate soil at the foundation, as previously discussed.Painted exteriors may include wall surfaces, porches, roof trim and brackets,cornices, dormers, and window surrounds. Most exteriors need repaintingevery 5-10 years due to the cumulative effect of sun, wind, and rain orlack of maintenance. Methods of paint removal that do not abrade or damagethe exterior materials should be evaluated. Because there is often morethan one material (for example, painted brick and galvanized roof ornaments),the types of paint removal or paint stabilization systems need to be compatiblewith each material. If paint has failed down to the substrate,it should be removed using either controlled sanding/scraping, controlledlight abrasives for cast iron and durable metals, chemicals, or low heat.If chemicals are used, it may be necessary to have the contractor contain,filter, or otherwise treat any residue or rinse water. Environmental regulationsmust be checked prior to work, particularly if a large amount of lead wastewill be generated or public water systems affected.
A cost analysis may show that, in the long run, repair and maintenanceof historic materials or in-kind replacement can be cost effective. Dueto the physical condition and location of wood siding, together with thecost of paint removal, a decision may be made to remove and replace thesematerials on some historic frame buildings. If the repair or replacementof historic cladding on a primary elevation is being undertaken, such replacementmaterials should match the historic cladding in material, size, configuration,and detail. The use of an artificial siding or aluminum coilstock panning systems over wooden trimwork or sills and lintels (as recommendedin some abatement guidelines) is not appropriate, particularly on principalfacades of historic buildings because they change the profile appearanceof the exterior trimwork and may damage historic materials and detailingduring installation. Unless the siding is too deteriorated to warrant repairand the cost is too prohibitive to use matching replacement materials (i.e.,wood for wood), substitute materials are not recommended.
The use of specialized encapsulant paint coatings on exteriors-in particular,moist or humid climates, and, to some extent, cold climates-is discouragedbecause such coatings may serve to impede the movement of moisture thatnaturally migrates through other paints or mask leaks that may be causingsubstrate decay. Thus, a carefully applied exterior paint system (eitheroil/alkyd or latex) with periodic repainting can be very effective.
Friction Surfaces. Interior features with surfaces that-functionally-rubtogether such as windows and doors, or are subject to human wear and tear,such as floor and steps, are known as friction surfaces. It is unclearhow much lead dust is created when friction surfaces that contain lead-basedpaint, but are top-coated with lead-free paint, rub together because muchof the earlier paint may have worn away. For example, if lead dust levelsaround windows or on painted floors are consistently above acceptable levels,treating nearby friction surfaces should be considered. If surfaces, suchas operable windows, operable doors, painted porch decks, painted floorsand painted steps appear to be generating lead dust, they should be controlledthrough isolating or removing the lead-based paint. Window and door edgescan be stripped or planed, or the units stripped on or off site to removepaint prior to repainting. Simple wooden stops and parting beads for windows,which often split upon removal, can be replaced. If window sash are severelydeteriorated, it is possible to replace them; and vinyl jamb liners caneffectively isolate remaining painted window jambs. Whenwindows are being treated within rehabilitation projects, their repairand upgrading are always recommended. In the event that part or all ofa window needs to be replaced, the new work should match in size, configuration,detail, and, whenever possible, material.
Painted floors often present a difficult problem because walking onthem abrades the surface, releasing small particles of lead-based paint.It is difficult to remove lead dust between the cracks in previously paintedstrip flooring even after sanding and vacuuming using special High EfficiencyParticulate Air (HEPA) filters to control the lead dust. If painted floorsare not highly significant in material, design, or craftsmanship, and theycannot be adequately cleaned and refinished, then replacing or coveringthem with new flooring may be considered. Stair treads can be easily fittedwith rubber or vinyl covers.
Accessible, projecting, mouthable surfaces. Accessible,chewable surfaces that can be mouthed by small children need not be removedentirely, as some health guidelines recommend. These accessible surfacesare listed as projecting surfaces within a child's reach, including windowsills, banister railings, chair rails, and door edges. In many cases, theprojecting edges can have all paint removed using wet sanding, a heat gunor chemical strippers, prior to repainting the feature. Ifthe homeowner feels that there is no evidence of unsupervised mouthingof surfaces, a regular paint may be adequate once painted surfaces havebeen stabilized. An encapsulant paint that adhesively bonds existing paintlayers onto the substrate extends durability. While encapsulant paint systemsare difficult to remove from a surface in the future, they permit retentionof the historic feature itself. If encapsulant paint is used on moldedor decorative woodwork, it should be applied in several thin coats to preventthe architectural detail from being obscured by the heavy paint.
Impact Surfaces. Painted surfaces near doorways and alongcorridors tend to become chipped and scraped simply because of their location.This is particularly true of baseboards, which were designed to protectwall surfaces, and also for doorjambs. Owners should avoid hitting paintedimpact surfaces with vacuums, brooms, baby carriages, or wheeled toys.Adding new shoe moldings can give greater protection to some baseboards.In most cases, stabilizing loose paint and repainting with a high qualityinterior paint will provide a durable surface. Clear panels or shieldscan be installed at narrow doorways, if abrasion continues, or these areascan be stripped of paint and repainted. Features in poor condition mayneed to be replaced with new, matching materials.
Other surfaces showing age or deterioration/ walls and ceilings.Many flat wall surfaces and ceilings were not painted with lead-based paint,so will need to be tested for its presence prior to any treatment. Flatsurfaces that contain deteriorating lead-based paint should be repairedfollowing the responsible approach previously cited (i.e., removing loosepaint to a sound substrate, then repairing damaged plaster using a skimcoat or wet plaster repair. Drywall is used only whendeterioration is too great to warrant plaster repair. If walls and ceilingshave a high lead content, and extensive paint removal is not feasible,there are systems available that use elastomeric paints with special fabricliners to stabilize older, though intact, wall surfaces.
If a new drywall surface needs to be applied, care should be taken thatthe historic relationship of wall to trim is not lost. Also, if there aresignificant features, such as crown moldings or ceiling medallions, theyshould always be retained and repaired.
Following treatment, particularly where interim controls have been used,ongoing maintenance and re-evaluation become critical. In urban areas,even fully lead-safe houses can be re-contaminated within a year from leador dirt outside the immediate property.
Thus, housing interiors must bekept clean, once lead hazard control measures have been implemented. Dustlevels should be kept down by wet sweeping porch steps and entrances ona regular basis. Vacuum cleaning and dusting should be repeated insideon a weekly basis or even more often. Vinyl, tile, and wood floor surfacesshould be similarly damp mopped. Damp washing of window troughs and sillsto remove new dust should be encouraged several times a year, particularlyin the spring and fall when windows will be open. Carpets and area rugsshould be steam cleaned or washed periodically if they appear to hold outsidedirt.
Housing should be inspected frequently for signs of deterioration byboth owner and occupant. Tenants need to be made aware of the locationof lead-based paint under lead-free top coats and instructed to contactthe owners or property managers when the paint film becomes disturbed. Any leaks, peeling paint, or evidence of conditions that maygenerate lead-dust should be identified and corrected immediately. Occupantsmust be notified prior to any major dust-producing project. Dry sanding,burning, compressed air cleaning or blasting should be not be used. Repairs, repainting, orremodeling activities that have the potential of raising significant amountsof lead dust should be undertaken in ways that isolate the area, reducelead-laden dust as much as possible, and protect the occupants.
Yearly dust wipe tests are recommended to ensure that dust levels remainbelow actionable levels. Houses or dwelling units that fail the dust-wipetest should be thoroughly re-cleaned with TSP, or its equivalent, washeddown, wet vacuumed and followed by HEPA vacuuming, if necessary, untila clearance dust wipe test shows the area to be under actionable levels(see Action Levels chart). Spaces that are thoroughly cleaned and maintainedin good condition are not a health risk.
The three-step planning process outlined in this Brief provides ownersand managers of historic housing with responsible methods for protectinghistoric paint layers and architectural elements, such as windows, trimwork,and decorative finishes. Exposed decorative finishes, such as painted muralsor grained doors can be stabilized by a paint conservator with a glazedor varnished layer without destroying their significance.
Reducing and controlling lead hazards can be successfully accomplishedwithout destroying the character-defining features and finishes of historicbuildings. Federal and state laws generally support the reasonable controlof lead-based paint hazards through a variety of treatments, ranging frommodified maintenance to selective substrate removal.
The key to protectingchildren, workers, and the environment is to be informed about the hazardsof lead, to control exposure to lead dust and lead in soil, and to followexisting regulations. In all cases, methods that control lead hazards shouldbe selected that minimize the impact to historic resources while ensuringthat housing is lead-safe for children.
Readers should become familiar with terminology and basic levels thattrigger concern and/or action. Check with the appropriate authorities ifyou have questions and to verify applicable action levels which may changeover time.
Blood lead levels: Generally from drawn blood and not a fingerstick test which can be unreliable. Units are measured in micrograms perdeciliter (ug/dl) and reflect the 1995 standards from the Centersof Disease Control:
Lead in paint: Differing methods report results in differingunits. Lead is considered a potential hazard if above the followinglevels, but can be a hazard at lower levels, if improperly handled.These are the current numbers as identified by the Department of Housingand Urban Development (1995):
Lab analysis of samples:
XRF reading: in milligram per centimeter squared
Lead dust wipe test: in micrograms per square foot
Lead in soil: high contact bare play areas, listed as parts permillion (ppm)
The following summarizes several important regulations that affect lead-hazardreduction projects. Owners should be aware that regulations change andthey have a responsibility to check state and local ordinances as well.
Title X (Ten) Residential Lead-Based Paint Hazard Reduction Act of1992 is part of the Housing and Community Development Act of 1992 (PublicLaw 102-550). It established that HUD issue "The Guidelines for theEvaluation and Control of Lead-Based Paint Hazards in Housing" (1995)to outline risk assessments, interim controls, and abatement of lead-basedpaint hazards in housing. Title X calls for the reduction of leadin housing that is federally supported and outlines the federalresponsibility towards its own residential units and the need for disclosureof lead in residences, even private residences, prior to sale.
Interim Final Regulations of Lead in Construction Standards (29CFR1926.62). Issued by the Department of Labor, Occupational Safety andHealth Administration (OSHA), these regulations address worker safety,training, and protective measures. It is based in part on environmentalair sampling to determine the amount of lead dust generated by variousactivities.
Toxic Substance Control Act; Title IV. The Environment ProtectiveAgency (EPA) has jurisdiction for setting standards for lead abatement.Also, EPA controls the handling and disposal of hazardous waste generatedduring an abatement project. EPA will develop standards to establish lead hazards, to certifyabatement contractors, and to establishwork practice standards for abatement activity. EPA Regional Offices canprovide guidance on the appropriate regulatory agency for states withintheir region.
State Laws: States generally have the authority to regulate theremoval and transportation of lead based paint and the generated wastegenerally through the appropriate state environmental and public healthagencies. Most requirements are for mitigation in the case of a lead-poisonedchild, or for protection of children, or for oversight to ensure the safehandling and disposal of lead waste. When undertaking a lead-based paintreduction program, it is important to determine which laws are in placethat may affect your project. Call the appropriate officials.
Local Ordinances: Check with local health departments, PoisonControl Centers, and offices of housing and community development to determineif there are laws that require compliance by building owners. Rarely areowners required to remove lead-based paint and most laws are to ensuresafety if a project is undertaken as part of a larger rehabilitation. Specialuse permits may be required when an environmental impact may occur dueto a cleaning treatment that could contaminate water or affect water treatment.Determine whether projects are considered abatements and will require specialcontractors and permits.
Owner's Responsibility: Owners are ultimately responsible forensuring that hazardous waste is properly disposed of when it is generatedon their own sites. Owners should check with their state office to determineif the abatement project requires a certified contractor. ( National certificationrequirements are not yet in place.) Owners should establish that the contractoris responsible for the safety of the crew and that all applicable lawsare followed, and that transporters and disposers of hazardous waste haveliability insurance as a protection for the owner. If an interim treatmentis being used to reduce lead hazards, the owner should notify the contractorthat lead-based paint is present and that it is the contractor's responsibilityto follow appropriate work practices to protect workers and to completea thorough clean-up to ensure that lead-laden dust is not present afterthe work is completed.
Current worker safety standards were established by OSHA's 29 CFR Part1926, Lead Exposure in Construction; Interim Final Rule, which became effectiveJune 3, 1993. These standards base levels of worker protection on exposureto airborne lead dust. They are primarily targeted to persons working withinthe construction industry, but apply to any workers who are exposed tolead dust for longer than a specific amount of time and duration. The InterimFinal Rule establishes an action level of 30 micrograms of lead dust percubic meter of air (30 ug/m3) based on an eight hour, time-weightedaverage, as the level at which employers must initiate compliance activities;and it also establishes 50 ug/m3 of lead dust as the permitted exposurelevel (PEL) for workers.
The standard identifies responsibilities before, during, and after theactual abatement activity necessary to protect the worker. Before the projectbegins, it requires an exposure assessment, a written compliance plan,initial medical surveillance, and training. The exposure assessment determineswhether a worker may be exposed to lead. OSHA has identified a number ofwork tasks expected to produce dust levels between 50 and 500 ug/m3of air, including manual demolition, manual scraping, manual sanding, heatgun applications, general cleanup, and power tool use when the power toolis equipped with a dust collection system. It is an OSHA requirement that,at a minimum, a HEPA filtered half-face respirator with a protection factorof 10 be used for these operations. Initial blood lead level (BLL) baselines are established for each worker. Actual dust levels are monitoredby air sampling of representative work activities, generally by an industrialhygienist or an environmental monitoring firm. Protective equipment isdetermined by the dust level. For all workers exposed at, or above, theaction level for over 30 days in a 12-month period, BLLs are tested ona regular basis of every 2 months for the first 6 months and every 6 monthsthereafter. After completing a project, maintenance, medical surveillance,and recordkeeping responsibilities continue.
HEPA vacuums, HEPA respirators, and HEPA filters, which substantiallyreduce exposure to lead dust, are available through laboratory safety andsupply catalogs and vendors.
Copies of 29 CFR Part 1926, Lead Exposure in Construction: Interim FinalRule, are available from the Department of Labor, Occupational Safety andHealth Administration, or may be found in any library with a current editionof the Code of Federal Regulation (CFR).
Chase, Sara B. Preservation Brief 28: Painting Historic Interiors.Washington, DC: US Department of the Interior, National Park Service, 1992.
"Coping with Contamination: A Primer for Preservationist,"Information; Booklet No. 70. Washington, DC: National Trustfor Historic Preservation, 1993.
Historic Buildings and the Lead Paint Hazard. Hartford,CT: Connecticut Historical Commission, 1990.
"Health Hazards in National Park Service Buildings", NPS-76Housing Design and Rehabilitation. Washington DC: US Departmentof the Interior, National Park Service, 1995.
Guidelines for the Evaluation and Control of Lead-Based Paint Hazardsin Housing. Washington, DC: US Department of Housing and Urban Development, 1995.
Jandl, H. Ward. Preservation Brief 18: Rehabilitating Historic Interiors- Identifying and Preserving Character-defining Elements. Washington, DC:US Department of the Interior, National Park Service, 1988.
Myers, John H. Preservation Briefs 9; Repair of Historic WoodenWindows. Washington, DC: US Department of the Interior, NationalPark Service, 1981.
OSHA Lead in Construction Standard (29 CFR 1926.62), Occupational Safetyand Health Administration, May 4, 1993 (Federal Register).
Park, Sharon C. and Camille Martone. "Lead-Based Paint in HistoricBuildings," CRM Bulletin. Washington, DC: US Deparartmentof the Interior, National Park Service. Vol. 13, No. 1, 1990.
Park, Sharon C. "Managing Lead in Building Interiors: An EmergingApproach," Interiors Handbook for Historic Buildings, Vol. II.Washington DC: Historic Preservation Education Foundation, 1993.
Park, Sharon C ."What to do about Lead-Based Paint," CRMBulletin. Washington, DC: U.S. Department of the Interior, NationalPark Service. Vol. 17, No. 4, 1994.
The Secretary of the Interior's Standards for the Treatment of HistoricProperties. Washington, DC: US Department of the Interior, National ParkService, 1992.
Title X (Residential Lead-Based Paint Hazard Reduction Act of 1992)of Housing and Community Development Act of 1992 (P.L. 102-550), October28, 1992.
Weeks, Kay D. and David Look, AIA. Preservation Briefs 10: ExteriorPaint Problems on Historic Woodwork. Washington DC: US Departmentof the Interior, National Park Service. 1982.
Deteriorated Lead-Based Paint: Paint known to contain lead thatshows signs of peeling, chipping, chalking, blistering, alligatoring orotherwise separating from its substrate.
Dust Removal: The process of removing dust to avoid creatinga greater problem of spreading lead particles; usually through wet or dampcollection or through the use of special HEPA vacuums.
Hazard Abatement: Long-term measures to remove the hazards oflead-based paint through selective paint stripping of deteriorated areas;or, in some cases, replacement of deteriorated features.
Hazard Control: Measures to reduce lead hazards to make housingsafe for young children. Can be accomplished with interim (short-term)or hazard abatement (long-term) controls.
Interim Control: Short-term methods to remove lead dust, stabilizedeteriorating surfaces, and repaint surfaces. Maintenance can ensure thathousing remains lead-safe.
Lead-based Paint: Any existing paint, varnish, shellac or othercoating that is in excess of 1.0 mg/cm2 as measured by an XRF detectoror greater than 0.5% by weight from laboratory analysis ( 5,000 ppm, 5,000ug/g, or 5,000 mg/kg). For new products, the Consumer Safety Act notes0.06% as the maximum amount of lead allowed in paint.
Lead-safe: The act of making a property safe from contaminationby lead-based paint, lead-dust, and lead in soil generally through shortand long-term methods to remove it, or to isolate it from small children.
Risk Assessment: An on-site investigation to determine the presenceand condition of lead-based paint, including limited test samples, andan evaluation of the age, condition, housekeeping practices, and uses ofa residence.
Sharon C. Park, AIA, is the Senior Historical Architect for thePreservation Assistance Division of the National Park Service. DouglasC. Hicks is the Deputy Chief of the Williamsport Preservation TrainingCenter of the National Park Service. Both authors served on the NationalPark Service Housing Task Force addressing lead-safe employee housing andon various national panels to discuss combining lead-safe housing, workersafety, and historic preservation concerns.
Kay D. Weeks was technical editor for this publication project. Theproject was completed under the direction of H. Ward Jandl, Deputy Chief,Preservation Assistance Division. The authors also wish to thank the followingindividuals for providing technical information or for supplying case studyprojects: Claudia Kavenagh, Building Conservation Associates, Inc; DavidE. Jacobs, Armand C. Magnelli, National Center for Lead-Safe Housing; EllisGoldman, William Wisner, and Catherine Hillard, HUD Office of Lead-BasedPaint Abatement; Ellis Schmidlapp, Landmarks Design Associates (Pittsburg,PA); Crispus Attucks Community Development Corporation (York, PA); CharleneDwin Vaughn and Rebecca
Rogers, the Advisory Council on Historic Preservation; George Siekkinen,National Trust for Historic Preservation; Deborah Birch, Einhorn YaffeePrescott Architects; Baird M. Smith and Quinn Evans Architects; Jack Waite,Messick Cohen Waite Architects; Jim Caufield, Pennsylvania Historical andMuseum Commission; Mike Jackson, Illinois Historic Preservation; MarthaRaymond, Ohio Historic Preservation Division; Susan Chandler, ConnecticutHistoric Commission; Steade Craigo, California Office of Historic Preservation;Christopher Jones, Rocky Mountain Regional Office, NPS; Rebecca Shifferand Kathleen Catalano Milley, Mid-Atlantic Regional Office, NPS; PeggyAlbee, North Atlantic Regional Office, Cultural Resources Center, NPS;Victoria Jacobson, AIA, Mt. Rainier National Park; E. Blaine Cliver, AnneE. Grimmer, Thomas C. Jester, Michael J. Auer, Charles A. Birnbaum, ASLA,and Charles E. Fisher of the Preservation Assistance Division, the NationalPark Service, and Thomas McGrath, Williamsport Preservation Training Center.
Washington, D.C. April, 1995
This publication has been prepared pursuant to the NationalHistoric Preservation Act of 1966, as amended, which directs the Secretaryof the Interior to develop and make available information concerning historicproperties. Technical Preservation Services (TPS), Heritage PreservationServices Division, National Park Service prepares standards, guidelines,and other educational materials on responsible historic preservation treatmentsfor a broad public.
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