NIOSH HEALTH HAZARD EVALUATION REPORT 

HETA #98-0285-2989 

Vermont Housing & Conservation Board 

Montpelier, Vermont 

December 2005 

DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health
ii 

PREFACE

The Hazard Evaluation and Technical Assistance Branch (HETAB) of the National Institute for 

Occupational Safety and Health (NIOSH) conducts field investigations of possible health hazards in the 

workplace. These investigations are conducted under the authority of Section 20(a)(6) of the Occupational 

Safety and Health (OSHA) Act of 1970, 29 U.S.C. 669(a)(6) which authorizes the Secretary of Health and 

Human Services, following a written request from any employers or authorized representative of 

employees, to determine whether any substance normally found in the place of employment has 

potentially toxic effects in such concentrations as used or found. 

HETAB also provides, upon request, technical and consultative assistance to federal, state, and local 

agencies; labor; industry; and other groups or individuals to control occupational health hazards and to 

prevent related trauma and disease. Mention of company names or products does not constitute 

endorsement by NIOSH. 

ACKNOWLEDGMENTS AND AVAILABILITY OF REPORT

This report was prepared by Aaron Sussell of HETAB, and Gregory Piacitelli of the Surveillance Branch, 

Division of Surveillance, Hazard Evaluations and Field Studies (DSHEFS). We gratefully acknowledge 

the assistance of Joanee LaTuchie, Vermont Housing and Conservation Board, and Ellen Tohn, National 

Center for Lead-Safe Housing (now Alliance for Healthy Homes), for arranging the residential 

demonstration project and Joseph Rodriguez, Hi-Tech Coatings, Inc. for his cooperation during the 

project. Assistance was provided by John McKernan and Mazan Abbas (Surveillance Branch) in 

conducting the field work and by Gregory Burr for report preparation. Analytical support was provided by 

Data Chem Laboratories, Salt Lake City, Utah. Desktop publishing was performed by Shawna Watts and 

Robin Smith. Editorial assistance was provided by Ellen Galloway. 

Copies of this report have been sent to the Vermont Housing and Conservation Board, the Alliance for 

Healthy Homes and the OSHA Regional Office. This report is not copyrighted and may be freely 

reproduced. The report may be viewed and printed from the following internet address: 

http://www.cdc.gov/niosh/hhe. Copies may be purchased from the National Technical Information 

Service (NTIS) at 5825 Port Royal Road, Springfield, Virginia 22161. 

For the purpose of informing affected employees, copies of this report 

shall be posted by the employer in a prominent place accessible to the 

employees for a period of 30 calendar days.
iii 

Highlights of Health Hazard Evaluation 

Highlights of the NIOSH Health Hazard Evaluation

Residential Lead-Based Paint Removal and Surface Preparation 

The National Institute for Occupational Safety and Health (NIOSH) received a request from the Vermont 

Housing and Conservation Board in 1998 to evaluate worker exposures to lead-contaminated dust when 

removing residential lead-based paint and preparing surfaces with lead-based paint for repainting. 

What NIOSH Did

 We measured exposures to lead dust during 

three paint removal/surface preparation 

methods. 

 We collected air samples and settled dust 

samples during four trials for each method. 

 We collected bulk paint samples from the 

exterior siding of the house and analyzed 

them for lead content. 

What NIOSH Found

 All sections of siding that were worked on 

were coated with lead-based paint. 

 The lead dust levels were high during dry 

scraping/power sanding without a properly 

functioning HEPA vacuum system. 

 Lead dust levels were lower during dry 

scraping/manual sanding. 

 Lead dust levels were lowest during dry 

scraping/power sanding with a properly 

functioning HEPA vacuum system and wet 

scraping/manual sanding. 

 All of the paint removal and surface 

preparation methods created high levels of 

lead in settled dust zero to 6 ft from the 

siding of the house. 

What Lead Abatement Managers Can Do

 Use power sanders for lead-based paint 

removal/surface preparation only if the 

sander is used with a properly-functioning 

HEPA vacuum dust collection system. 

 Use respirators to control worker exposures 

to lead during dry scraping and power 

sanding. 

 Where possible use wet scraping and manual 

sanding instead of dry scraping/manual 

sanding. 

 Place heavy plastic drop cloth on the ground 

extending out 10 ft to 20 ft from all areas of 

work on lead-based paint. 

What the Lead Abatement Employees Can 

Do 

 Follow recommended work practices for 

lead-safe renovation work. 

 See your doctor for a blood lead level test 

periodically. 

What To Do For More Information:

We encourage you to read the full report. If you 

would like a copy, either ask your health and 

safety representative to make you a copy or call 

1-513-841-4252 and ask for 

HETA Report #98-0285-2989
iv 

Health Hazard Evaluation Report 98-0285-2989 

Vermont Housing & Conservation Board 

Montpelier, Vermont 

December 2005 

Aaron L. Sussell 

Gregory M. Piacitelli 

SUMMARY

The National Institute for Occupational Safety and Health (NIOSH) received a request in 1998 from the 

Vermont Housing and Conservation Board (VHCB) to evaluate worker exposures to lead-contaminated dust 

and the dispersion of dust to surroundings associated with exterior paint removal and surface preparation. The 

VHCB arranged a demonstration project that included three paint removal/surface preparation methods 

performed by a Vermont licensed lead abatement contractor. The objective was to determine which method 

produced the least amount of dust exposure and dispersion. A NIOSH site visit was made in August 1998; the 

sampling results were provided to the VHCB in 1999. 

During the demonstration project workers removed exterior lead-based paint from clapboard siding of a singlefamily wood-frame house using three methods: dry scraping with manual sanding, wet scraping with manual 

sanding, and dry scraping with power sanding. NIOSH investigators conducted task-based sampling during 

four trials per method. Trials took place on different sections of the painted siding. Samples collected during 

each were for personal breathing zone (PBZ) and area airborne lead (PbA) (both NIOSH Manual of Analytical 

Methods [NMAM] Method 7105), lead in paint, and lead in the dispersed surface dust (PbS). PbS samples 

were collected using stationary dustfall collectors, each containing a clean unfolded pre-moistened hand wipe 

(Wash n’ Dri®) centered in the tray. Eight PbS samples were collected in two rows on the ground at zero, 6, 10, 

and 20 feet perpendicular to the siding. 

The mean lead concentration measured in painted surfaces was 18.7% (range for section means 4.8% – 

27%). The highest PBZ PbA exposures were measured during dry scraping/power sanding with an 

improperly functioning (80%-blocked) HEPA vacuum dust collection system: 820 and 1600 micrograms 

per cubic meter (:g/m3

) as task-based time-weighted averages (TWA) over 1-2 hours. PBZ PbA 

concentrations during dry scraping/manual sanding were lower, ranging from 29 to 160 ug/m3

, and dry 

scraping/power sanding with a properly functioning HEPA vacuum system and wet scraping/manual 

sanding produced the lowest PBZ PbA results, ranging from 3.5 to 53 :g/m3

, task-based TWA. The area 

PbA results at 10 ft from the work surfaces were low, ranging from 0.16 to 8.2 :g/m3

. For all three 

methods, mean concentrations of PbS measured on the ground at zero ft and 6 ft from the house 

foundation ranged from 1300 to 7,600,000 :g/ft2

. After statistically controlling for distance, method, 

paint Pb concentration and the percent paint removed from substrate in a linear model, distance was 

significantly associated with PbS (p-value= < 0.0001). 
v 

NIOSH investigators found that worker exposures to lead during dry scraping/power 

sanding without functional dust collection controls were a health hazard. Worker 

exposures during wet scraping/manual sanding were relatively low, but could be a health 

hazard if the activity is performed 8 hours or more. After paint removal, high 

concentrations of lead in settled dust were found at distances of zero to 10 ft from the 

work surfaces. Recommendations included (1) use effective engineering controls on 

power sanding equipment to limit lead dust exposure and dust dispersion to surroundings; 

(2) use respirators to reduce worker exposure to lead dust during dry scraping and power 

sanding until engineering and/or administrative controls are effective in reducing 

exposures below the OSHA PEL; and (3) use good hygiene practices. 

Keywords: NAICS 238320 (House painting), lead, lead abatement, paint removal, sanding, scraping, dust
Table of Contents 

Preface..........................................................................................................................................................ii

Acknowledgments and Availability of Report..........................................................................................ii

Highlights of Health Hazard Evaluation .................................................................................................iii

Summary.....................................................................................................................................................iv

Introduction.................................................................................................................................................1

Background .................................................................................................................................................1

Methods........................................................................................................................................................1

Environmental Sampling........................................................................................................................2

Evaluation Criteria .....................................................................................................................................3

Lead Exposure.........................................................................................................................................4

Lead in Surface Dust and Soil................................................................................................................4

Results and Discussion................................................................................................................................5

Conclusions..................................................................................................................................................6

Recommendations.......................................................................................................................................7

References....................................................................................................................................................8

Health Hazard Evaluation Report No. 98-0285-2989 Page 1 

INTRODUCTION

In 1998 the National Institute for Occupational 

Safety and Health (NIOSH) received a request 

from the Vermont Housing and Conservation 

Board (VHCB) for an evaluation of worker 

exposures to lead-contaminated dust and the 

dispersion of dust to surroundings associated with 

several exterior lead-based paint (LBP) surface 

preparation methods. In collaboration with the 

National Center for Lead-Safe Housing, VHCB 

arranged a demonstration project that included 

three paint removal/surface preparation methods. 

The project took place at a single-family home near 

Montpelier, Vermont. The house was selected 

because it had deteriorated exterior LBP and the 

owner was willing to participate in the 

demonstration. The work was performed by a 

Vermont licensed lead abatement contractor. One 

NIOSH site visit was made for this evaluation in 

August 1998. The sampling results were provided 

to VHCB in 1999. 

BACKGROUND

The Vermont Housing and Conservation Board is 

an independent, state-supported funding agency 

that provides grants, loans, and technical assistance 

to nonprofit organizations, municipalities and state 

agencies for the development of perpetually 

affordable housing and for the conservation of 

important agricultural land, recreational land, 

natural areas and historic properties in Vermont. 

VHCB administers grant funds from the U.S. 

Department of Housing and Urban Development 

(HUD) for lead hazard reduction in housing owned 

by non-profit housing organizations, private 

landlords, and homeowners. The focus of this 

VHCB program is on pre-1978 housing that 

contains high levels of lead-based paint and has 

young children residents. The eligible units must 

have at least one bedroom and not be intended 

primarily for occupancy by the elderly. Since 1995, 

more than 600 apartments and homes throughout 

Vermont have been made lead-safe through the 

Lead Paint Hazard Reduction Program 

administered by VHCB. 

A number of federal and state regulations to 

address lead-based paint hazards in private housing 

have resulted from a 1992 U.S. law known as Title 

X of the Residential Lead–Based Paint Hazard 

Reduction Act of 1992.1

 In 1995, Vermont enacted 

legislation to address lead-based paint hazards in 

rental housing and child care facilities (Act 165). 

The Act prohibited the use of many common paint 

preparation techniques considered hazardous to 

workers and/or the occupants of the property 

during lead hazard reduction work. At the time of 

this evaluation wet scraping was the only 

acceptable method for paint removal. The 

Occupational Safety and Health Administration 

(OSHA) also regulates residential lead work in 

Vermont. The OSHA lead in construction standard 

[29 CFR 1926.62 (1993)] requires that when 

employers engage in certain “trigger tasks” (e.g., 

dry manual scraping and sanding), they must 

presume hazardous worker exposures and provide 

workers with the specified levels of respiratory 

protection, protective work clothing, and 

equipment until they document through an 

exposure assessment that the measures are not 

necessary.2

 

VHCB had found that it was difficult to remove 

some types of deteriorated exterior LBP with wet 

hand scraping alone. VHCB wanted NIOSH to 

evaluate the levels of lead-contaminated dust or 

paint chips generated by several methods for 

removing exterior LBP. 

METHODS

The purpose of the study was to compare worker 

and area airborne lead (PbA) exposures and lead in 

surface dust (PbS) levels resulting from three LBP 

removal methods. The methods, commonly used 

by home renovators, painters, and lead abatement 

workers to remove paint and prepare exterior 

surfaces with LBP for repainting, were categorized 

by NIOSH investigators as dry scraping/manual 

sanding, dry scraping/power sanding, and wet 

scraping/manual sanding. These methods, each a 

combination of two tasks, are defined in Table 1. 

Dry scraping/manual sanding and wet 

scraping/manual sanding differed only in whether 

the surface was misted with water using hand spray 

bottles prior to scraping. The third method was a 5-
Page 2 Health Hazard Evaluation Report No. 98-0285-2989 

inch random orbital power sander provided with 

local exhaust ventilation, consisting of a 

commercial-grade high-efficiency particulate airfilter (HEPA) vacuum. 

The demonstration project took place at a rural 

location near Montpelier, Vermont, on the exterior 

of a 11⁄2-story wood frame house with clapboard 

siding, approximately 80 years old, with 

deteriorated LBP. Twelve trials of approximately 

1-hour duration were done to evaluate the three 

paint removal methods – four trials per method. 

Clapboard siding on the north, east, and west sides 

of the house (the south side was not included 

because almost all of the original paint had already 

fallen off) was divided into 10 sections about 10 

feet (ft) in width, which were marked with vertical 

lines from foundation to the roof line. The three 

methods were randomly assigned to nine sections 

of the house to control for variations in paint 

condition and paint lead concentration between 

sections of siding. Section locations and their 

corresponding paint conditions are shown in Figure 

1, and the assignments used for the method trials 

are shown in Table 2. Figure 2 shows the field 

sampling set up. Sections designated for paint 

removal extended from the foundation to the roof 

line except on the north side of the house (main 

entry location), where one section (3) was the 

clapboard siding below the porch roof, and two 

sections (4, 10) were adjacent halves of the wood 

shingle siding above the porch roof. Section 10 was 

not used because the paint was not deteriorated and 

was very hard to remove. 

The participating contractor, who provided two 

workers, was licensed in Vermont for lead 

abatement and lead hazard reduction work. The 

two workers were sampled simultaneously, but on 

nonadjacent sections of the house to reduce crosscontamination of the PbA and PbS samples. The 

workers used ladders and scaffolding to access 

areas on the second story level. The duration of the 

12 trials was approximately 1 hour (hr) so that the 

settled dust measurements would be comparable 

between trials (mean trial duration: 1.00 hr, range: 

0.80–1.43 hr). However, in practice paint removal 

for some sections required longer periods due to 

equipment problems and time required to move 

ladders and plastic sheeting. Workers began 

removing paint at the top of each section and 

worked down toward the foundation. 

Prior to the start of work, VHCB had done a lead 

inspection on the house and determined that all 

exterior siding was coated with LBP. VHCB 

scheduled the paint removal work so that the 

occupants could be relocated during the 

demonstration project to prevent their exposure to 

lead dust. The site preparation done by the 

contractor included sealing all exterior windows 

and doors from the outside with 6-mil polyethylene 

(poly) plastic sheeting. The poly sheeting was 

extended 20 ft out from the house foundation on 

the three sides where paint was disturbed, and was 

rolled up at the end of each work day. 

Environmental Sampling 

One personal breathing-zone (PBZ) air sample was 

collected during each trial while a worker removed 

paint from a section of the house. Two area air 

samples were collected during each trial to assess 

the LBP dust dispersion and potential exposure of 

bystanders. The area sampling pumps were placed 

immediately abutting the exterior siding (zero ft) 

and 10 ft out along a line perpendicular to the 

siding. The area samples were collected 1.5 to 5 ft 

above the ground (depending on available 

horizontal surfaces or hooks), and 6 ft downwind of 

the section midpoint, if the wind direction was 

roughly parallel to the exterior siding. 

Air samples were collected and analyzed using 

NIOSH Method 7105 (graphite furnace atomic 

absorption spectrophotometry), modified for 

microwave digestion of the samples.3

 The flow rate 

used for the sampling pumps was 4.0 liters per 

minute (Lpm); pumps were calibrated in the field 

pre- and post-sampling. The limits of detection 

(LODs) for lead in air samples ranged from 0.05 to 

0.07 micrograms per sample (:g/sample), 

depending on the dilution factor. The limit of 

quantitation (LOQ) for all samples was 0.2 :g 

/sample. Air concentrations are reported in 

micrograms per cubic meter (:g/m3

). 

Eight PbS samples were collected during each trial. 

Samples were collected using stationary dustfall 

collectors, which consisted of commercially-
Health Hazard Evaluation Report No. 98-0285-2989 Page 3 

available 6"x9"x2" plastic trays (EKCO Consumer 

Plastic Inc®, Model 514-1, sold at K-Mart®), each 

containing a clean unfolded pre-moistened hand 

wipe (Wash n’ Dri®) centered in the tray (the hand 

wipes are 5.5"x8" unfolded). Just before paint 

removal on a section of the house started, eight dust 

collectors were arranged on the ground in two rows 

perpendicular to the house foundation. One row 

extended out from the section midpoint and the 

other was located parallel to it, at 6 ft horizontal 

distance in the direction closest to downwind (a 

portable wind vane was used to determine wind 

direction). Each row had a dust collector at zero, 6, 

10 and 20 feet out from the house foundation. The 

hand wipes were kept moist during dust sampling 

by misting them every 10–15 minutes with water 

from a hand spray bottle (settled dust did not stick 

to the hand wipes if they were allowed to dry). The 

collectors were picked up approximately 15 

minutes after the work ceased for each section. The 

hand wipes were then folded inward and 

transferred to 50 mL plastic centrifuge tubes with 

gloved hands or tweezers. No attempt was made to 

transfer dust that had fallen in the tray but not on 

the hand wipes. Between trials the trays were 

washed with soap and water. Results are reported 

in micrograms per square foot (:g/ft2

). PbS 

samples were analyzed for lead using NIOSH 

Method 7082, modified for digestion of hand 

wipes. 

Three bulk paint samples were collected from 

siding or wood trim in each designated section 

of the house. For each sample a measured area 

of paint was removed from a known surface area 

by (1) scoring all layers of the paint with an 

approximately 1-inch diameter laboratory hole 

cutter (designed for cutting holes in rubber 

stoppers), (2) heating the paint gently with a heat 

gun to soften it, and (3) scraping all paint off 

within the scored area using a stainless steel 

paint scraper. The paint chips were collected on 

a piece of paper and transferred to 50 mL plastic 

centrifuge tubes. Paint samples were analyzed 

for lead using NIOSH Method 7082, modified 

for digestion of paint films. 

EVALUATION CRITERIA

As a guide to the evaluation of the hazards posed 

by workplace exposures, NIOSH field staff use 

environmental evaluation criteria for the 

assessment of a number of chemical and 

physical agents. These criteria are intended to 

suggest levels of exposure to which most 

workers may be exposed up to 10 hours per day, 

40 hours per week for a working lifetime 

without experiencing adverse health effects. It 

is, however, important to note that not all 

workers will be protected from adverse health 

effects even though their exposures are 

maintained below these levels. A small 

percentage may experience adverse health 

effects because of individual susceptibility, a 

pre-existing medical condition, and/or a 

hypersensitivity (allergy). In addition, some 

hazardous substances may act in combination 

with other workplace exposures, the general 

environment, or with medications or personal 

habits of the worker to produce health effects 

even if the occupational exposures are controlled 

at the level set by the criterion. These combined 

effects are often not considered in the evaluation 

criteria. Also, some substances are absorbed by 

direct contact with the skin and mucous 

membranes, this may increase the overall 

exposure. Finally, evaluation criteria may 

change over the years as new information on the 

toxic effects of an agent become available. 

The primary sources of environmental 

evaluation criteria for the workplace are: (1) 

NIOSH Recommended Exposure Limits 

(RELs),4

 (2) the American Conference of 

Governmental Industrial Hygienists’ (ACGIH®) 

Threshold Limit Values (TLVs®),5

 and (3) the 

U.S. Department of Labor, Occupational Safety 

and Health Administration (OSHA) Permissible 

Exposure Limits (PELs).6

 Employers are 

encouraged to follow the OSHA limits, the 

NIOSH RELs, the ACGIH TLVs, or whichever 

are the more protective criteria. 

OSHA requires an employer to furnish 

employees a place of employment that is free 

from recognized hazards that are causing or are 

likely to cause death or serious physical harm 
Page 4 Health Hazard Evaluation Report No. 98-0285-2989 

[Occupational Safety and Health Act of 1970, 

Public Law 91–596, sec. 5(a)(1)]. Thus, 

employers should understand that not all 

hazardous chemicals have specific OSHA 

exposure limits such as PELs and short-term 

exposure limits (STELs). An employer is still 

required by OSHA to protect their employees 

from hazards, even in the absence of a specific 

OSHA PEL. 

TWA exposure criteria refer to the average 

airborne concentration of a substance during a 

normal 8- to 10-hour workday. Some substances 

have recommended STEL or ceiling values 

which are intended to supplement the TWA 

where there are recognized toxic effects from 

higher exposures over the short-term. 

Lead Exposure 

Occupational exposure occurs via inhalation of 

lead-containing dust and fume and ingestion 

from contact with lead-contaminated surfaces. 

Symptoms of lead poisoning include weakness, 

excessive tiredness, irritability, constipation, 

anorexia, abdominal discomfort (colic), fine 

tremors, and “wrist drop.”7,8,9 Overexposure to 

lead may also result in kidney damage, anemia, 

high blood pressure, infertility and reduced sex 

drive in both sexes, and impotence. An 

individual's blood lead level (BLL) is used as the 

best indication of recent exposure to, and current 

absorption of lead.10 Measurement of zinc 

protoporphyrin (ZPP) levels in blood can be a 

good indicator of the toxic effect of lead on 

heme synthesis in red blood cells. Elevated ZPP 

levels due to lead exposure, which may remain 

months after the exposure, are an indicator of 

chronic lead intoxication. Persons without 

occupational exposure to lead usually have a 

ZPP level of less than 40 micrograms per 

deciliter (:g/dL).11 Because other factors, such 

as iron deficiency, can cause an elevated ZPP 

level, the BLL is a more specific test in the 

evaluation of occupational exposure to lead. 

In the OSHA lead standards for general industry 

and construction, the PEL and Action Level for 

PbA is 50 and 30 :g/m3

 (both 8-hour TWAs), 

respectively. These limits are intended to 

maintain worker BLLs below 40 :g/dL; medical 

removal is required when an employee’s BLL 

reaches 50 :g/dL.12,2 After concluding that its 

1978 REL of 100 :g/m3

 as an 8-hour TWA did 

not sufficiently protect workers from the adverse 

affects of exposure to inorganic lead, 13 NIOSH 

adopted the OSHA PEL. However, NIOSH has 

conducted a literature review of the health 

effects data on inorganic lead exposure and finds 

evidence that some of the adverse effects on the 

adult reproductive, cardiovascular, and 

hematologic systems, and on the development of 

children of exposed workers can occur at BLLs 

as low as 10 :g/dL.14 At BLLs below 40 :g/dL, 

many of the health effects would not necessarily 

be evident by routine physical examinations, but 

represent early stages in the development of 

disease. In recognition of this, voluntary 

standards and public health goals have 

established lower BLL exposure limits to protect 

workers and their children. The ACGIH TLV®

for PbA is 50 :g/m3

 as an 8-hour TWA, with 

worker BLLs to be controlled to #30 :g/dL. A 

national health goal is to eliminate all 

occupational exposures that result in BLLs 

greater than 25 :g/dL.15

Lead in Surface Dust and 

Soil 

Lead contamination in dust and soil, which is 

commonly found in the U.S. due to the past use 

of lead in gasoline and paints, and from 

industrial emissions, is a health risk to children. 

Lead-contaminated surfaces may also be a 

source of occupational exposure for workers. 

Lead exposure may occur either by direct handto-mouth contact, or indirectly through 

contamination of hands, cigarettes, cosmetics, or 

food. 

Generally there is little or no correlation 

between surface lead levels and employee PBZ 

exposures in the workplace. The amount of lead 

ingested in contaminated work areas depends on 

the effectiveness of administrative controls, 

personal hygiene practices, and available 

facilities for maintaining personal hygiene. 

There are no federal occupational standards that 
Health Hazard Evaluation Report No. 98-0285-2989 Page 5 

set limits for surface or soil lead contamination. 

EPA has defined a dustBlead hazard as a surface 

in a residential dwelling or childBoccupied 

facility that contains a lead loading equal to or 

greater than 40 :g/ft2 (equivalent to 0.43 mg/m2) 

on floors or 250 :g/ft2 (equivalent to 2.7 

mg/m2

) on interior window sills, based on wipe 

sample results.16 EPA has defined a soilBlead 

hazard as bare soil on a residential real property 

or on the property of a childBoccupied facility 

that contains total lead equal to or exceeding 400 

parts per million (ppm) (ppm is equivalent to 

micrograms per gram [:g/g] for soil) in a play 

area or average of 1,200 ppm in the rest of the 

yard based on soil sample results.16

RESULTS AND 

DISCUSSION

The 30 paint sampling results were 

approximately normally distributed, with an 

overall mean concentration of 18.7% lead by 

weight (standard deviation [SD]=6.50). The 

mean paint lead concentrations for nine sections 

of the house varied from 4.8% to 27% (see 

Table 3). Section 10, which was not used for 

paint removal, had a mean paint lead 

concentration of 18%. Except for section 9, 

which was 4.8%, the mean paint lead 

concentrations for sections of the house worked 

on ranged from 17% to 27% lead. All of the 

mean lead concentrations were well above the 

federal action level for lead-based paint of 0.5% 

lead by weight, but were fairly typical for 

exterior paint on an 80-yr-old house in the 

northeastern U.S. In addition to the paint 

removal method used, mean paint lead 

concentration is one of the most important 

factors in determining the amount of leadcontaining dust produced by removal of 

residential lead-based paint.17 The amount of 

paint deterioration on each section of the house 

used was qualitatively rated before surface 

preparation work began, all of the sections used 

were rated as having either moderate or minimal 

deterioration. Minimal deterioration meant that 

100% of the surface was coated with paint. 

Moderate deterioration meant some paint 

(estimated to be 2% to 20%) had fallen off the 

surface. 

As shown in Table 3, the highest PBZ PbA 

exposures occurred during dry scraping/power 

sanding. The task-based PbA exposures during 

this method were highly variable, ranging from 

3.5 to 1600 :g/m3

, TWA over the approximately 

1 to 2 hours of actual work time. Part of the 

variability was due to a problem with the HEPA 

vacuum equipment. Near the beginning of the 

third trial for the dry scraping/power sanding 

method, we discovered that the HEPA vacuum 

canister inlet was about 80% blocked 

(apparently the inlet had been clogged by carpet 

fibers and debris during use at a previous job). 

The contractor immediately replaced the vacuum 

with another HEPA vacuum for completion of 

most of the third trial and all of the fourth trial. The 

lower PBZ PbA exposures for this method were 

associated with (1) removing minimallydeteriorated paint (we estimated that only 5% 

was removed) with the lowest percent lead 

content (4.8%) with the power sander and the 

partially-blocked HEPA vacuum; and (2) 

removing moderately-deteriorated paint with 

higher lead content (17%) with the power sander 

and a properly functioning HEPA vacuum. The 

highest PBZ PbA exposures during dry 

scraping/power sanding occurred when 

removing moderately-deteriorated higher lead 

content paint (20%–21%) while using a randomorbital power sander connected to the 80%-

blocked HEPA vacuum. It should be noted that 

the two highest PBZ exposures (820 and 1600 

ug/m3

) would exceed the OSHA PEL for lead of 

50 :g/m3

, TWA over an 8-hour workday, even 

assuming that no additional paint scraping or 

sanding was performed during the day. Due to 

the variability of exposures during dry 

scraping/power sanding, even if HEPA vacuum 

equipment is used, employers should provide 

respirators for personal protection until it can be 

shown that the exposures on a job are well 

controlled and below the PEL. 

The remaining paint removal techniques 

produced lower lead exposures. PbA 

concentrations during dry scraping and manual 

sanding ranged from 29 to 160 :g/m3

, TWA 
Page 6 Health Hazard Evaluation Report No. 98-0285-2989 

over approximately 1 hour of actual work time. 

The lowest PBZ PbA exposures were measured 

during wet scraping combined with manual 

sanding, ranging from 4.7 to 53 :g/m3

, TWA 

over the actual work time of 1 to 2 hours. 

The area PbA results at 10-ft distance from the 

work surfaces (downwind from section 

midpoint, if there was measurable wind) ranged 

from none detected (estimated concentration 

0.16 :g/m3

) to 8.2 :g/m3. The highest area 

levels at 10 ft, 15 :g/m3 and 8.2 :g/m3

, occurred 

during trials for dry scraping/power sanding and 

wet scraping/manual sanding, respectively. Area 

PbA levels during the other three trials for wet 

scraping/manual sanding were very low, 

however. Area PbA collected zero ft from work 

surfaces were highly variable, ranging from 0.4 

to 3400 :g/m3

. The area PbA results at zero ft 

were lower than the respective PBZ sample 

results for nine trials and higher than the PBZ 

samples during three trials. The zero-ft area PbA 

results of 3400 :g/m3

 and 35 :g/m3 during dry 

scraping/power sanding were significantly 

higher than the PBZ sample results, 1600 :g/m3

and 3.5 :g/m3

, respectively. The area PbA 

results were collected to estimate the exposures 

of bystanders observing the work. These results 

indicated that bystanders should stay at least 10 

ft away from paint removal and surface 

preparation to avoid high PbA exposures. 

The results obtained for 64 lead in settled dust 

(PbS) samples collected during paint removal 

are presented in Table 4. The distribution of 

results approximated log normal, so the PbS data 

were log-transformed prior to statistical 

analyses. No significant difference was found 

between the midpoint and the matched 6 ftdownwind samples (p-value = 0.19), so only 

midpoint PbS results are presented here. As 

shown in Table 4, the geometric mean 

concentrations for PbS collected at distances of 

6, 10, and 20 feet from the surface where the 

paint was being removed all showed a sharp 

decline (up to 99%) when compared to the PbS 

levels measured at the foundation of the house. 

This reduction in PbS levels occurred regardless 

of the type of work task or the section of the 

home being treated. This suggests that for the 

paint removal methods demonstrated in this 

project, many of the LBP particles generated by 

either scraping or sanding were aerodynamically 

large and settled out of the air quickly. The 

mean differences in PbS concentrations between 

any paired distances (zero vs. 6 ft, 10 vs. 20 ft, 6 

vs. 10 ft, etc) were statistically significant 

(ANOVA, p-values from <0.0001 to 0.001). 

After statistically controlling for distance, 

method, paint Pb concentration and the percent 

paint removed from substrate in a linear model, 

only distance was significantly associated with 

PbS (p-value= < 0.0001, df 1). For all three 

methods, high mean concentrations of PbS were 

measured on the ground at zero ft and 6 ft from 

the house foundation (range: 1300 to 7,600,000 

ug/ft2

). At all distances except zero ft, dry 

scraping/power sanding resulted in higher PbS 

levels than the other methods, and a high mean 

PbS level was measured at 10 ft from the work 

surface (3100 ug/ft2

). These outdoor PbS levels 

collected with the dustfall collectors are not 

directly comparable to the HUD lead dust 

clearance standards, which refer to wipe sample 

results, or to the EPA residential bare soil 

guideline, which refers to bulk soil sample 

results. However, the mean lead concentrations 

in settled dust at zero and 6 feet for all methods, 

and at 10 ft for dry scraping/power sanding were 

very high, and likely would create a health 

hazard to young children occupying the 

residence if the lead-containing dustfall 

measured was allowed to fall on the ground 

rather than contained and wrapped up in poly 

sheeting, and taken off site for proper disposal. 

CONCLUSIONS

 The highest PbA exposures occurred during 

dry scraping/power sanding conducted 

without a properly functioning HEPA 

vacuum system. These exposures represent 

a health hazard to unprotected workers and 

bystanders within 10 ft of the work. 

 PbA exposures during dry scraping/power 

sanding were significantly lower when the 

random-orbital sander was connected to a 

properly functioning HEPA vacuum (dust 

collection system). With a properly 

functioning HEPA vacuum system the PbA 
Health Hazard Evaluation Report No. 98-0285-2989 Page 7 

exposures for this method were among the 

lowest of the three methods evaluated. 

 PbA exposures during dry scraping/manual 

sanding approached the OSHA Action Limit 

for lead of 30 μg/m3

, and could exceed the 

OSHA PEL of 50 μg/m3 if scraping and 

sanding was performed continuously for up 

to an 8-hour workday. 

 PbA exposures during wet scraping/manual 

sanding were lower, but could exceed the 

OSHA PEL of 50 μg/m3

 if this task was 

performed throughout an entire 8-hour work 

day. 

 For all of the methods demonstrated, area 

PbA levels at a distance of at least 10 ft from 

the work surfaces were low, and do not 

represent a health hazard for short-term 

(one- to several-hour) airborne lead 

exposures of bystanders. 

RECOMMENDATIONS

The following recommendations are based on 

the findings of this investigation and are offered 

to improve the safety and health of workers 

involved in scraping and sanding on leadcontaining surfaces. 

1. Use power sanding equipment only when it is 

provided with effective dust collection 

equipment to limit lead dust exposure. To 

ensure proper functioning and dust collection, 

thoroughly inspect hoses and inlets of HEPA 

vacuum, or other dust collection equipment, 

prior to each use on the job site. Publications 

developed by NIOSH provide guidance on 

controls for hand sanders. These include the 

following: 

 Control of Wood Dust from Orbital Hand 

Sanders (http://www.cdc.gov/niosh/hc9.

html); and Control of Wood Dust from 

Random Orbital Hand Sanders 

(http://www.cdc.gov/niosh/hc8.html). 

2. Use respirators to reduce worker exposure to 

lead dust during dry scraping and power 

sanding until it can be shown that engineering 

and/or administrative controls effectively 

reduce exposures below the NIOSH REL. As 

a minimum they should be NIOSH-approved 

half-mask respirators with an N100 filter 

designation. 

3. Use wet scraping/manual sanding instead of 

dry scraping/manual sanding whenever 

feasible to reduce or eliminate potentially 

hazardous worker lead exposures. 

4. Develop a written respiratory program. This 

program should include the following 

components: respirator selection, medical 

evaluation, fit testing, respirator use, 

respirator maintenance and care, filter 

identification, training and information, 

program evaluation, and recordkeeping. 

5. Use poly sheeting to cover the ground at least 

10 ft out from foundation for manual sanding 

methods, and at least 20 ft from foundation 

for power sanding methods to protect 

surroundings from lead contamination during 

lead-based paint removal. Avoid paint 

removal on windy days. Use cleanup 

techniques that minimize dust generation at 

the end of the refinishing project, including 

HEPA vacuuming of all surfaces. 

6. Use good hygiene practices, such as washing 

hands prior to eating or drinking and 

changing or laundering work clothes before 

returning home to reduce the possibility of 

para-occupational or “take-home” lead dust 

exposures. 

7. To prevent unnecessary hazards lead 

exposures among bydstanders, residents, 

neighbors, and other observers, establish a 

resticted entry parimeterm, at least 10 ft from 

the active work surfaces, and if possible 

establish a larger restricted area, particularly 

for young children, who are at greatest risk of 

exposure to lead–based paint dust on surfaces. 
Page 8 Health Hazard Evaluation Report No. 98-0285-2989 

REFERENCES

 1. Residential Lead–Based Paint Hazard 

Reduction Act of 1992, Public Law 102–550, 

from U.S. House Report 102–1017, October 28, 

1992. 

 2. CFR. Code of Federal Regulations. 29 

CFR, Part 1926.62. OSHA construction industry 

lead standard. Washington, DC: U.S. 

Government Printing Office, Office of the 

Federal Register. 

 3. NIOSH [1994]. NIOSH manual of 

analytical methods, 4th edition. Eller, P and 

Cassinelli, ME, Eds. Cincinnati, OH: U.S. 

Department of Health and Human Services, 

Public Health Service, Centers for Disease 

Control and Prevention, National Institute for 

Occupational Safety and Health, DHHS 

(NIOSH) Publication No. 94–113. 

 4. NIOSH [1992]. Recommendations for 

occupational safety and health: compendium of 

policy documents and statements. Cincinnati, 

OH: U.S. Department of Health and Human 

Services, Public Health Service, Centers for 

Disease Control and Prevention, National 

Institute for Occupational Safety and Health, 

DHHS (NIOSH) Publication No. 92-100. 

 5. ACGIH [2004]. 2004 TLVs® and BEIs®: 

threshold limit values for chemical substances 

and physical agents. Cincinnati, OH: American 

Conference of Governmental Industrial 

Hygienists. 

 6. CFR [2003]. 29 CFR 1910.1000. Code of 

Federal Regulations. Washington, DC: U.S. 

Government Printing Office, Office of the 

Federal Register. 

 7. Hernberg S, et al. [1988]. Lead and its 

compounds. In: Occupational medicine. 2nd ed. 

Chicago, IL: Year Book Medical Publishers. 

 8. Landrigan PJ, et al. [1985]. Body lead 

burden: summary of epidemiological data on its 

relation to environmental sources and toxic 

effects. In: Dietary and environmental lead: 

human health effects. Amsterdam: Elsevier 

Science Publishers. 

 9. Proctor NH, Hughes JP, Fischman ML 

[1991]. Lead. In: Chemical hazards of the 

workplace. 3rd ed. Philadelphia, PA: J.B. 

Lippincott Company, pp 353–357. 

 10. NIOSH [1978]. Occupational exposure to 

inorganic lead. Cincinnati, OH: U.S. 

Department of Health, Education, and Welfare, 

Public Health Service, Center for Disease 

Control, National Institute for Occupational 

Safety and Health, DHEW (NIOSH) Publication 

No. 78–158. 

 11. Lauwerys RR and Hoet P [1993]. 

Industrial chemical exposure: guidelines for 

biological monitoring, Second Edition. Ann 

Arbor, MI: Lewis Publishers, p. 62. 

 12. CFR. 29 CFR, Part 1910.1025. OSHA lead 

standard for general industry. Code of Federal 

regulations. Washington, DC: U.S. Government 

Printing Office, Office of the Federal Register. 

 13. 62 Fed. Reg. 206 [1997]. National Institute 

for Occupational Safety and Health: 

occupational exposure to inorganic lead: request 

for comments and information. 

 14. Sussell A, et al. [1998]. Protecting workers 

exposed to lead–based paint hazards: a report to 

Congress. Cincinnati, OH: U.S. Department of 

Health and Human Services, Public Health 

Service, Centers for Disease Control and 

Prevention, National Institute for Occupational 

Safety and Health, DHHS (NIOSH) Publication 

No. 98–112. January 1998–revised with minor 

technical changes. 

 15. DHHS [2000]. Healthy people 2010–

conference edition; National health promotion 

and disease objectives. Washington, DC: U.S. 

Department of Health and Human Services. 

Available on the internet at: 

www.health.gov/healthypeople/Document/defau

lt.htm 
Health Hazard Evaluation Report No. 98-0285-2989 Page 9 

 16. 66 Fed. Reg. No. 4 [2001]. U.S. 

Environmental Protection Agency: LeadBbased 

paint hazards, January 5, 2001. (To be codified 

at 40 CFR Part 745) 

17. Sussell A, Hart C, Wild D, and Ashley K 

[1999]. An evaluation of worker lead exposures 

and cleaning effectiveness during removal of 

deteriorated lead-based paint. Applied Occ and 

Env Hygiene, 14:177-185. 
Page 10 Health Hazard Evaluation Report No. 98-0285-2989 

Table 1. Exterior Lead Based Paint (LBP) Removal/Surface Preparation Methods 

Evaluated 

Vermont Housing and Conservation Board, Montpelier, Vermont 

HETA 98-0285-2989

Method Work Description

Dry scraping/manual sanding A hand scraper with a (replaceable) 2-inch tungsten-carbide blade 

is used to remove loose and peeling paint, followed by dry hand 

sanding with coarse sandpaper to smooth edges. 

Dry scraping/power sanding A hand scraper with a (replaceable) 2-inch tungsten-carbide blade 

is used to remove loose and peeling paint, followed by power 

sanding with a pneumatic 5-inch diameter five hole random 

orbital sander attached to a commercial-grade HEPA vacuum. 

The sander is used to smooth edges, not remove the remaining 

paint. 

Wet scraping/manual sanding Before scraping, a hand-held spray bottle is used to wet surfaces 

with a water mist. A hand scraper with a (replaceable) 2-inch 

tungsten-carbide blade is used to remove loose and peeling paint, 

as surfaces are kept wet with periodic misting with water. The 

scraping is followed by wet hand sanding with coarse sandpaper 

to smooth edges. The hand sanding block is dipped frequently in 

water keep sandpaper wet. 

Table 2. Assignments for Trials of Three Paint Removal/Surface Preparation Methods 

Vermont Housing and Conservation Board, Montpelier, Vermont 

HETA 98-0285-2989

House 

section

Worker Day Method

1 A 1 Dry scraping/manual sanding 

1 A 2 Dry scraping/manual sanding 

2 A 1 Wet scraping/manual sanding 

2 A 3 Dry scraping/power sanding 

3 B 2 Wet scraping/manual sanding 

4 B 2 Wet scraping/manual sanding 

4 B 3 Dry scraping/manual sanding 

5 B 1 Dry scraping/manual sanding 

6 B 1 Wet scraping/manual sanding 

7 A 2 Dry scraping/power sanding 

8 A 2 Dry scraping/power sanding 

9 B 2 Dry scraping/power sanding 
Health Hazard Evaluation Report No.98-0298-2989 Page 11 

Table 3. Personal Breathing-Zone and Area Air Sample Results for Lead during Paint Removal/Surface PreparaVermont Housing and Conservation Board, Montpelier, Vermont HETA 98-0285-2989 

PBZ PbA‡ 

:g/m3

A

Task Day Section 

of 

house* 

Mean 

Paint 

Pb (%) 

Treated 

Area 

(ft2)† 

% of 

Existing 

Paint 

Removed

Actual 

Work 

Time 

(min) Task 

TWA§ 

Estimated 8-

hr. TWA**

0 ft Task 

TWA 

1 5 24 29 30 56 160 18.7 42 1 1 17 48 10 60 83 10.3 9.1 2 1 17 63 10 60 120 15 15 

Dry scraping/manual 

sanding 

3 4 19 24 5 62 29 3.8 17 

2 A 7 20 103 50 126 1600 420 3400 

2 B 8 21 53 50 64 820 109 17 

2 A 9 4.8 45 10 53 3.5 0.39 35 

Dry scraping/power 

sanding 

3 C 2 17 36 50 59 7.4 0.91 2.6 

1 2 17 40 10 60 4.7 0.59 0.4 1 6 27 39 20 55 50 5.7 4.8 2 3 18 53 10 75 53 8.3 13 

Wet scraping/manual 

sanding 

2 4 19 23 90 67 7.5 1.1 12 

 50

Occupational Exposure Criteria: Occupational Safety and Health Administration Permissible Exposure Limit (PEL) NIOSH Recommended Exposure Limit (REL) 50* See Figure 1 for location. †Treated area refers to the amount of painted surface area that was scraped and/or sanded. ‡PbA = Lead in air concentration, expressed in micrograms per cubic meter. §Task TWA= PbA concentration calculated for the actual work time. **8-hr. TWA = PbA concentration estimated for an 8-hour work day, assuming no additional lead exposure during the day. ††None detected result; the LOD/2(0.5) and sample volume were used to calculate an estimated value. A Used a 5-inch disk random orbital sander attached to Nilfisk VT-60® high efficiency particulate air (HEPA) filter vacuum with ~80% blocked hose. B Used a 5-inch disk random orbital sander attached to Nilfisk VT-60® HEPA vacuum with ~80% blocked hose (5 min) and then Nilfisk GM-80 HEPA vacuum C Used a 5-inch disk random orbital sander attached to Nilfisk GM-80® HEPA vacuum.
Page 12 Health Hazard Evaluation Report No. 98-0285-2989 

Table 4. Mean Results for Lead in Settled Dust during Paint Removal/Surface Preparation 

Vermont Housing and Conservation Board, Montpelier, Vermont 

HETA 98-0285-2989 

Perpendicular distance from exterior siding, ft 

Paint Removal Method 0 6 10 20

Dry Scraping and 

Manual SandingA 3,400,000 3,800 580 17 

Dry Scraping and 

Power SandingB 4,300,000 6,300 3,100 321 

Wet Scraping and 

Manual SandingB 7,600,000 1300 110 56 

All results are mean PbS, ug/ft2; samples collected in dustfall collectors during the tasks. A

PbS results are geometric means for three trials on different siding sections. 

B

PbS results are geometric means for four trials on different siding sections. 
Health Hazard Evaluation Report No.98-0298-2989 Page 13 

Figure 1. Site Layout with Designated Areas and Paint Condition

5

6

9

7

8

2

1

clapboard siding

poor cond.

clapboard siding

fair cond.

clapboard siding

good cond.

clapboard siding

fair cond.

clapboard siding

good cond.

clapboard siding

fair cond.

clapboard siding

poor cond.

Roof peak

Below porch roof

clapboard siding

fair cond.

Above porch roof

wood shingles

fair condition

4 Above porch roof 3

wood shingles

(not used)

10
Page 14 Health Hazard Evaluation Report No. 98-0285-2989 

Figure 2. Sampling Set Up during a Paint Removal Method

A 

B 

A) PbA and PbS sampling while a worker performs the dry scraping/power sanding method. B) 

Collection of a PbS sample with dustfall collector. 
DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention National Institute for Occupational Safety and Health 4676 Columbia Parkway Cincinnati, OH 45226-1998 OFFICIAL BUSINESS Penalty for private use $300 

Delivering on the Nation's promise: 

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through research and prevention

To receive NIOSH documents or information 

about occupational safety and health topics 

contact NIOSH at: 

1-800-35-NIOSH (356-4674) 

Fax: 1-513-533-8573 

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or visit the NIOSH web site at: 

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