Skip to main content

Lead-Safe Wisconsin: Lead Hazard Investigator and Risk Assessor Study Guide

There are three lead certification exams you can take:

  • The Risk assessor exam includes 125 questions and is covered in all six modules of the study guide.
  • The Lead hazard investigator exam includes 75 questions and is also covered in most of the modules in the study guide.
  • The Lead inspector exam includes 75 questions, most of which are covered in Module 3 of the study guide. See the lead inspector exam page for more information.

Learn more about the lead certification exams

To study for the exam, do the following:

  • Review the course manuals from your initial lead risk assessor and inspector courses.
  • Complete the modules, activities, and quizzes in the study guide below. First, view the links in the tab below from federal and state agencies. The links include requirements and guidelines that are covered on the exam. You will be directed to important publications and rules from these agencies. The study guide is organized into six modules, each with sub-topics. There is a practice test at the end of each module.

Study guide modules

Sources of Lead Exposure

  • Learn common sources of lead exposure at Lead-Safe Wisconsin Sources of Lead, including lead-based paint and dust, lead in soil, and drinking water, among others.
  • Read about where lead is found in various jobs and hobbies at the EPA. Read which hobbies increase your risk of lead exposure and whether they generate lead dust.

Health Effects

  • In children:
    • Read more about Lead-Safe Wisconsin Sources of Lead Poisoning and when the symptoms and health effects can appear. Then, review what research shows when children have elevated blood lead levels and how children get lead poisoned.
    • Read about surveillance and data collection of childhood lead exposure at CDC's Blood Lead Surveillance.
    • Learn about how children get poisoned by lead, including the health hazards, prevalence rates, and highest risk populations on pages 1-4 to 1-5 in Chapter 1.
  • In adults:

Quiz

Regulations

DHS Certification

  • In Wisconsin, the agency that regulates lead training and certification is the Department of Health Services (DHS) through Lead-Safe Wisconsin.
  • DHS 163 includes the requirements for certification when working with lead-based paint hazards.
  • In DHS 163, read about the activities in target house and child-occupied facilities that require Wisconsin certification. Read more about how to get trained and certified to perform lead work.
  • A lead risk assessor, once certified, can perform a variety of duties. Read the following sections to find out what they can do:
  • Read a short list of activities a lead risk assessor may conduct in DHS 163.
    • Read DHS's Lead Risk Assessor page about how to become a lead risk assessor and what work a risk assessor can do. After reading the top part of the page, scroll down to learn how to apply to become a lead risk assessor
  • If you complete any lead investigation activities (for example, clearance, lead inspection, risk assessment, hazard screen), submit a quarterly summary report.
    • Read the requirements of the quarterly lead investigation report in DHS 163.
  • Read general information about how to do clearance on pages 15-4 to 15-6 in Chapter 15. On these pages, find out who is qualified to conduct clearance.
    • To gain further information about who can conduct clearances, read the qualifications for clearance examiners on page 15-10 under Regulatory Qualifications.
    • Go to Module 6: Clearance below for more specific information about clearance for Wisconsin.

Quiz

Building Components and Systems

  • Windows, doors, and stairs are common sources of lead-based paint.
  • Read about the building components, specifically windows, that contain lead dust in Chapter 5.
    • Go to E. Dust Sampling or start reading on page 5-40 (3. Selection of Locations within Rooms). As you read, review the basic plan for taking dust wipe samples, including selection of rooms and components.
  • Read about Window Systems (11-37), Door Systems (11-40), and Stair Systems (11-41) in Chapter 11. View illustrations of a stair system with various parts labeled on page 11-42.
  • Study the components of windows (page 12-19), doors (12-20), and stairs (12-30) in Chapter 12.

Testing Combinations

  • Read about Lead-based Paint Inspections on pages 7-5 to 7-7 in Chapter 7.
    • To learn about testing combinations, read step #8 on page 7-6.
    • It is not recommended to only take paint chip samples for an inspection, but there are cases when it is necessary. Read about these cases on pages 7-13 to 7-14.
    • The standard for what constitutes lead-based paint can be found in the How to Do It section on page 7-5. Read #3.
    • Read the definition of lead-based paint on page 7-16.

Painted Surfaces Inventory

  • Read the definition of testing combinations on page 7-17 in Chapter 7. Take note of which factors cannot be used to determine paint history or the presence of lead-based paint
    • Then, examine and study the examples of interior and exterior building component types that should be tested in Table 7.1 on page 7-18.
    • Review the various items to record in an inventory during a lead-based paint inspection.
      • Read about Inspections in Single-Family Housing on page 7-19.
      • Review the six parts in this section, starting with determining the number of room equivalents, on pages 7-20 to 7-21.

Multi-Family

  • Read the overview of how to conduct a lead inspection in a multi-family unit in Chapter 7.
    • Read about inspections in multi-family housing starting on page 7-36.
    • Read Statistical Confidence in Dwelling Unit Sampling on page 7-36, focusing on how to select units based on pre-1960 and 1960 to 1977 housing units.
    • Read page 7-37 about the selection of housing units, common areas, and exterior site areas
    • Analyze Table 7.3 on pages 7-38 to 7-39, which shows the number of units to be tested based on the dates of building construction.
    • Read the two important steps about how the units should be selected on the bottom of page 7-37 and the top of page 7-40
    • Read how to select specific units on page 7-40 using the random number formula. In the middle of the page, it lists some formulas to determine which unit to randomly select. Read the example about 50 units in the development, specifically how a random unit is selected. Take the Module 3 Quiz to do a practice problem
    • Become familiar with, and learn how to use, Table 7.3 (Number of Units to be Tested in Multi-family Building or Developments) on page 7-38 and 7-39. Take the Module 3 Quiz to do a practice problem
    • Read Classification of XRF Results in Multi-family Housing on pages 7-41 to 7-42. Pay special attention to the part about testing combinations and if the XRF readings come back positive or negative. Also, find out the minimum number of components that must be tested depending on whether previous test samples were positive or negative
    • On page 7-43, review HUD’s Multi-family Decision Flowchart (Figure 7.3).
      • This chart will help you determine whether lead-based paint (LBP) is present, or not present, development-wide.
      • On page 7-42, read the paragraph before the flowchart, which also explains how it is determined if LBP is present in the building.
      • As you read this description and analyze the chart, pay attention to the %’s and which decision would be made (Yes / No) based on those percentages.

XRF Analyzers

  • Read about Xray Florescent Devices (XRFs) when performing lead-based paint inspections in C. Other Sources of Information on pages 7-10 to 7-13 in Chapter 7.
    • On page 7-13, read a general overview of when to use an XRF Performance Characteristic Sheet.
    • Read about substrate correction when interpreting XRF readings on page 7-26. On page 7-27, read when substrate correction is NOT required, and if it is, read 2. Substrate Correction Procedure on pages 7-27 to 7-28.
    • Learn about how many readings you need to take in each room using an XRF Analyzer on page 7-22.
    • Read about the Number and Location of XRF Readings on page 7-22.
    • Read the definitions of Building Component Types on page 7-16 and Testing Combination on page 7-17. Review Table 7.2 about distinct testing combinations.
    • Review about calibration checks on an XRF on page 7-25 to 7-26.
  • Read DHS's requirements for XRF Devices:
    • Read the information about what to consider before buying an XRF, applying for certification, and which agency licenses and maintains registration of XRFs in Wisconsin.
    • Under the section Before buying an XRF, review the Performance Characteristic Sheet (PCS) to find a list of XRF models. Examine the various sections and information on the sheet.

Paint Chip Sampling

  • Get a general overview of paint chip sample collection on page 5-51 in Chapter 5.
    • In the section titled Paint Chip Sample Collection and Analysis. Read up to page 5-54.
    • Read about paint testing methods on pages 5-51 to 5-54. Read the methods used to identify lead-based paint during inspections and risk assessments, and which surfaces should be tested for lead-based paint.
  • Read about laboratory testing for lead in paint-chip samples on page 7-45 to 7-50 in Chapter 7. including number of samples to take, the size, and laboratory analysis methods. You can also read how to collect paint chip samples, and what to do before, during, and after collecting the paint chip samples.
    • Read page 7-59 about how to do inspections in multi-family housing. Find out which forms to include when you send paint chip samples to the laboratory.

Analyzing Results

  • Read how to do a lead-based paint inspection on page 7-5 in Chapter 7.
    • Read step #3, specifically the HUD/EPA standard for lead-based paint.
    • Read on page 7-22 about the locations where you need to take XRF Readings, including which surfaces to avoid testing. Read about substrate correction procedures on page 7-27. In the first paragraph, read about some of the reasons why high readings may occur when using an XRF Analyzer.
    • Read how results should be reported to the lab in Units of Measure on page 7-47.

Quiz

Project Scope

  • On Lead-Safe Wisconsin: Resources for Lead Investigators, read about the work practice standards and checklists for risk assessments. On the site, scroll down to Lead investigation tools, and click on Report templates, self-review checklists, and regulatory updates. Review the updates to regulations, and for any documented methodologies, refer to the HUD’s Guidelines.
  • Read the Evaluation Options on pages 5-9 to 5-13 in Chapter 5.
    • Read #’s 1, 2, and 3 on page 5-9 in the Evaluation Options section.
    • Analyze Table 5.1 on page 5-10 to find out the differences between a risk assessment, lead hazard screen, and lead-based paint inspection.
    • Read a full description of a risk assessment on page 5-11 and a lead-based paint inspection on page 5-13.
  • Read about the purposes of a lead hazard screen and how it is different from a risk assessment on the bottom of page 5-11 and top of page 5-12. Examine Figure 5.1 on page 5-12. This figure shows how inspectors determine whether to do a risk assessment or lead hazard screen.
  • Read about the requirements for Elevated Blood Lead (EBL) Investigations:

Building Condition Survey

  • Read Step #3, or conducting a building survey, on page 5-7 in Chapter 5.
    • On page 5-20 of about conducting a risk assessment, read about obtaining a floor plan and site plan sketches. As you read, note what the floor plan should include in a home.
    • You will use this floorplan to complete Forms 5.2-5.5 (field report, paint chip sampling, single-surface and composite sampling, soil samples) located on pages 5-102 to 5-106.

Visual Assessment

  • Review the areas of a building or dwelling you need to identify during a Visual Assessment on page 5-21 in Chapter 5.
  • On pages 5-24-5-34, review the 7 areas where hazards can be located. Read the what to look for sections and examine the images to gain further understanding.
  • Learn where lead from paint, dust, and soil could be, especially in and around older homes and buildings, in EPA's Protect Your Family from Lead Sources.

Multi-Family

  • Read about which rooms to test for a visual assessment when doing a risk assessment on pages 5-21 to 5-22 in Chapter 5.
  • Read the methods of unit selection for risk assessments for five or more similar dwellings on pages 5-64 to 5-67.
  • Pay attention to the Identification of Deteriorated Paint (Form 5.2) on page 5-24. After reading the definition, review the first paragraph to determine what deteriorated paint you should identify in a risk assessment
  • Read about conducting a building condition inspection on page 5-20. Take note of the examples provided of paint or substrate deterioration.
  • Examine the table (Table 5.4) of painted components on page 5-27.
    • In Chapter 7, look at Table 7.1 on page 7-18 for a longer list. Review and take notes on the types of painted components that could result in paint or substrate deterioration.
  • On page 5-21, read the overall scope and purpose of a visual assessment. As you read page 5-21, and the additional information on page 5-22, note which areas of a building or dwelling should be examined.
  • On pages 5-25 to 5-26, read the six types of paint deterioration and look at the accompanying photos. Read some common substrate deterioration problems, including peeling from metal, wood, plaster walls, and masonry surfaces.
  • Read about the dangers of lead exposure for chewable surfaces while conducting risk assessments. Read the section on page 5-32 about identifying chewable surfaces during the visual assessment.
    • Read Identification of Chewable Surfaces on page 5-32.
    • Look at the photos of examples of chewable surfaces.
    • Read the Hazard Definition and What to Look For to get examples of chewable surfaces children can access on page 5-33.

Occupant Questionnaire

  • On page 5-19 to 5-20 in Chapter 5, read occupant questionnaires, specifically the first two paragraphs about the Individual Occupied Units. Read the purpose of the occupant questionnaire, as well as what information you are trying to get.
  • To gain a better understanding, and also access a tool to use for your future risk assessments, examine a questionnaire for a lead hazard risk assessment for individually occupied units, or Form 5.0 on pages 5-99 to 5-100.

Dust Wipe Sampling

  • On page 5-35 in Chapter 5, read the introduction to dust sampling and the methods for sample collection on pages 5-35 to 5-38.
  • Read about how to interpret results of dust-lead samples on page 5-70.
  • Read about which surfaces you need to take dust wipe samples on pages 5-40 to 5-44. Read how to select rooms (page 5-40), which building components to test (5-40), and dust sampling for friction surfaces (page 5-42).
  • Read the requirements for taking single surface dust samples of a dwelling unit in DHS 163.
  • Learn how to do a risk assessment:
    • In the step-by-step summary of how to do a risk assessment on page 5-7, read Step #6 about conducting dust sampling. While reading, take notes about how many dust wipe samples you need to take in each dwelling and room.
    • Read the Lead-Safe Wisconsin: Public Health Interventions. Scroll down and click on the lead risk assessment video. Watch the 20 minute video and take notes about the important steps to conducting a risk assessment.
  • Review the chart of the type of samples you need to take for a risk assessment in table 5.1 on page 5-10. The chart also includes which samples to take for a lead hazard screen and lead-based paint inspection. As you analyze the chart, take notes about which samples are required for each one, specifically a risk assessment. If the chart says ‘Yes,’ that means a sample is required
  • Review Form 5.4a, or the Field Sampling Form for Single-Surface Sampling, also on page 5-104. Read the four important points at the bottom. Read #2, which lists how accurately you need to measure the size of the area being sampled.
  • Read how to interpret the laboratory results for dust wipe samples in DHS 163. Read how you achieve clearance for samples taken on interior floors, windowsills, window wells, troughs, and porches. Clearance is achieved only when the samples are less than the values shown in (8) a, am, b, and c.
  • Read more about wipe sampling of settled dust for lead determination in Appendix 13.1. You must use a chain of custody form when submitting samples to a laboratory.

Soil Sampling

  • Read in DHS 163 the three areas you need to take soil samples for a risk assessment.
  • Read about how to conduct composite soil sampling on page 5-8 in Chapter 5, specifically point #7. Identify in the text the areas where you need to take soil samples.
    • Closely examine Form 5.5 (Field Sapling Form for Soil) on page 5-106.
  • Read the definition of how EPA regulations define a soil-lead hazard at the top of page 5-33.
    • On page 5-76, read the section about Play Area Hazard Determination, and identify which lead level (in ppm) is considered a soil-lead hazard.
    • On the same page, 5-76, read Non-play Area Hazard Determination, or the rest of the yard, and take note of what is considered a soil-lead hazard in ppm.
    • View the Field Sampling Form for Soil on page 5-106.
    • On page 5-55, read about the sample collection methods for soil. Then, at the top of page 5-56, read the short description about how to submit samples and where you can get the chain-of-custody form.
  • Read about collecting soil samples for lead determination bin Appendix 13.3. Under the section Equipment, Materials and Supplies, read J. Laboratory submittal form. When submitting samples to a laboratory, you need to complete a chain of custody form.

Paint Testing

  • Read about when you should conduct dust sampling and paint chip sampling during a risk assessment on page 5-35 in Chapter 5.
  • Review the Field Paint Chip Sampling Form on page 5-103. This is the form you can use when sending paint chip samples to a laboratory.
  • Read about paint chip sampling in Appendix 13.2. On the last page in the section heading Laboratory Submittal, read about what to include on the chain of custody form.

Quiz

Final Report

  • Read about the purposes of the risk assessment report on page 5-84 to 5-85 in Chapter 5. The report documents hazard control options. At the bottom of page 5-93, read the section about Supporting Information (EPA-required). Find out how long you need to keep the forms and reports.
  • Read about a Risk Assessment Report on pages 5-84 to 5-91. You do not need to read everything, but as you review each page, note what you need to include in the report. Page 5-90 includes a summary list of what to include in the report. Review the information on this page and also the bullet-points of required information.
  • A risk assessment report needs to include hazard control options, ideally in a table format. Review the example table formats on pages 5-92 to 5-93. On page 5-93, read the recommendations for maintenance and monitoring.

Hazard Control Options

  • Read how to coordinate renovation and lead hazard control on page 4-7 in Chapter 4.
  • Read part B at the bottom of page 4-7 and top of page 4-8. Focus on which surfaces of windows contain the most lead dust.
  • Lead hazards in the home include friction and impact surfaces which can make lead dust and lead paint chips. Go to page 5-28 in Chapter 5 to read about friction surfaces, and then read more about impact surfaces starting on page 5-31.
  • Read the nine steps to implement interim controls for soil lead hazards on page 11-61 in Chapter 11.
  • Read about some principles of abating lead-based paint hazards from page 12-11 to 12-13 in Chapter 12. At the top of page 12-11, read how long abatement should last, the preference for abatement versus interim controls, and the advantages of abatement measures.
  • Read the definition of enclosure methods on page 12-24. Scroll through pages 12-24 to 12-32, and read the recommended enclosure methods for both interior and exterior surfaces. The recommendations for interior surfaces begins on page 12-28 and exterior starts on 12-31.
  • Read about removal and replacement procedures for interior walls at the top of page 12-23. In the second paragraph about Interior Walls, take notes about the recommendations for abating plaster walls.
  • Read how to abate lead by encapsulation on pages 13-3 to 13-4 in Chapter 13. Read how encapsulants can be used on certain surfaces.
  • There are some differences between interim controls and abatement when lead contaminates soil.
    • Interim Controls:
      • Read pages 11-62 to 11-67 about the six types of interim control measures for soil.
      • Read the definition of soil lead hazards at the top of page 11-62. Note the ppm (or µg/g) when lead is present in areas frequented by children under 6. For other parts of the yard, as well as the dripline in non-play areas, identify the number (a different one) to determine a soil lead hazard.
      • Hint: Lab results for soil lead hazards can be reported in ppm or µg/g, and they would be the same amounts.
      • On pages 11-62 to 11-64, read the different types of interim controls for lead hazards in soil.
    • Abatement Measures:
      • Read about the abatement measures when soil is lead-contaminated on page 12-43. On page 12-43, identify what size of area (in square feet) and lead amount (in µg/g) would constitute a lead-hazard. Then, on page 12-44, read what µg/g would require soil abatement.
      • Once you find those numbers, read about soil abatement methods on page 12-44. Read and review the steps for soil abatement on page 12-44 to 12-45.

Paint Removal and Stabilization

  • First, read the methods to remove paint on pages 12-8 to 12-9 in Chapter 12. Note which methods you should avoid at the top of page 12-8.
    • Read further about the prohibited methods on pages 11-14 to 11-16 in Chapter 11.
  • Read the recommended paint removal practices on pages 11-30 to 11-31.
  • Go to page 11-22 and read about how to stabilize paint. Read steps 5 to 8 describing how to remove and then apply new paint.

Calculating and Interpreting Sample Results

  • For the test, you will need to know how to calculate the dust-lead loading. This study guide will walk you through some examples below, and then you can do a practice problem in the Module 5 Quiz.
  • Read about why EPA standard are based on loading instead of concentration in the last paragraph on page 5-71 in Chapter 5.
  • Read through the example of how dust-lead loading is calculated on page 5-71.
  • Dust wipe sample levels are reported by the laboratory in units of micrograms per square foot (µg/ft2) instead of concentration (µg). This is called the dust-lead loading
  • When taking floor samples, calculate them by square feet.
    • For example:
      • Surface: Floor
      • Wiped area: 2 ft x 2ft = 4 ft2
      • Total Lead: 200 micrograms (µg) of lead
      • How to calculate the dust-lead loading:
        • Step 1: First calculate square feet, or ft2
        • Step 2: Then, divide the dust wipe sample (in micrograms of lead (µg) by the square feet
        • Step 3: Calculate
          • 200 µ / 4 ft2 = 50 µg/ft2
    • Try Yourself:
      • Surface: Window trough
      • Wiped area: 0.525 ft2
      • Total Lead: 210 µg
      • Calculate the dust-lead loading. After you finish, look at the Answer Key at the end of Module 5
  • In Method of Sample Collection on page 5-35, read the definition of a field blank sample on page 5-36 and 5-38.
  • Review which equipment is required when collecting dust wipe samples:
    • On page 5-38, read the equipment required when collecting dust wipe samples. Read the four bullet points at the top of the page. Take note of the equipment required for dust sample.
    • In Appendix 13.1, read the materials and supplies needed to collect dust samples. Read A through L on the first two pages.
  • Learn how to calculate the surface area for a dust wipe sample. Surface area is expressed in square feet (ft2).
    • Follow the steps to calculate the surface area of a dust wipe sample for a 5-inch by 24-inch section of a window sill.
      • Step 1: convert inches to feet. To do this, divide inches by 12
        • 5-inch = ______ ft
        • 24-inch = _____ ft
      • Step 2: Multiply the two numbers
        • ______ ft x ______ ft = _______ ft2
      • Scroll down to check your answer in the Module 4 Extra Credit section once you finish.
  • Determining if dust-lead hazards are present is based on the arithmetic mean. Read page 5-47, bullet-point #3, to learn more. Knowing how to calculate the mean is important for risk assessors. Try a problem yourself below, and check your answer in the Extra Credit section:
    • You collect 3 dust samples from window sills in different rooms. The lab reports each same in micrograms per square foot ((µg/ft2): 19, 58, and 72 µg/ft2
    • What is the arithmetic mean? First, add them all together to get the sum
      • Sample 1: ___ + Sample 2: ___ + Sample 3: ___=____ µg/ft2
    • Then, divide by the number of dust samples taken:____ =____
      • Arithmetic Mean = ____ µg/ft2
    • Often, a test will round up to the nearest 10th. Round it up yourself.
      • Rounded up ____ = ____ µg/ft2

Answer Key

  • Dust-lead Loading Calculation:
    • What was the result of your dust-lead loading calculation?
    • If you got 400 µg/ft2, you are correct!
  • Surface Area Calculation:
    • Step 1: convert inches to feet. To do this, divide inches by 12
      • 5-inch = .42 ft
      • 24-inch = 2 ft
    • Step 2: Multiply the two numbers
      • .42 ft x 2 ft = .84 ft2
  • Arithmetic Mean for dust wipe samples:
  • Sample 1: 19 + Sample 2: 58 + Sample 3: 72 = 149
  • Divide by the number of dust samples taken: = 3
    • Arithmetic Mean = 49.67
    • Rounded up = 49.7

Quiz

  • On Lead-Safe Wisconsin: Resources for Lead Investigators read about work practice standards and checklists for clearances. Scroll down to lead investigation tools, and click on Report templates, self-review checklists, and regulatory updates.
  • Wisconsin’s lead regulations include more specific restrictions about who may conduct clearance. In DHS 163, Read about who may conduct clearances in Wisconsin. Also, continue reading about some prohibitions on who may conduct clearances and what they are not permitted to do.
  • Read in DHS 163 the protocol when conducting clearances.

Visual Inspection

  • Read in DHS 163 about performing a visual inspection of work.
  • Read the purposes of a visual inspection in the first and second paragraphs on page 15-17 in Chapter 15.
    • Read about the visual assessment for settled dust and debris on page 15-19. In the first paragraph, find out if there should be any evidence of settled dust. Read further in the paragraph, and find out at least three things the clearance examiner should document and tell the contractor if there is visible dust on page 15-19.

Dust Wipe Sampling

  • Read when dust wipe sampling should be done on page 15-11 in Chapter 15. Specifically, find out how long an examiner should wait to allow airborne leaded-dust to settle before conducting a clearance.
  • Review the table about the minimum number and location of dust samples when conducting clearances on pages 15-27 to 15-28.
  • Study this table carefully! On the test, you will be asked to identify the number and location of samples needed based on the clearance category.
  • The information in Table 15.1 is in description form under the Clearance Categories on pages 15-25 to 15-26. Read the 4 categories for clearance, which have different standards whether containment was used, the number of rooms, and whether composite or single-surface samples are collected.
  • Clearance is achieved when the lab results for certain areas, including interior floors, porches, interior windowsills, and window troughs, are less than certain amounts. Read DHS 163 about clearance standards. The standards, expressed in μg/ft2 and written in a., am., b., and c., are different for the four areas mentioned above. Make sure you know these numbers to prepare for the State exam.
  • There are a number of factors that affect the locations and number of samples that need to be collected. The HUD Guidelines and DHS 163 have more information about this process:
  • Read in DHS 163 about the clearance protocol, read ‘Location of sampling for work conducted in containment’ and ‘without containment.’ Then, read in DHS 163 about random sampling in multi-family dwellings.
  • Refer to the Dust Wipe Sampling under Risk Assessment in this Study Guide for how to collect a dust wipe sample.

Sample Analysis and Interpretation

  • Interpreting lab results should be done by comparing them to the standards in DHS 163.
    • The results are reported in micrograms per square foot (μg/ft2)
      • IMPORTANT!
      • If a dust sample is equal to or exceeds (greater than) the clearance standard, it fails
      • If a dust sample is less than the clearance standard, it passes
    • Practice 1: You collect a dust wipe sample from an interior floor, and the result is 8 μg/ft2. Would clearance pass or fail? Check the correct answer in the Answer Key below.
    • Practice 2: You collect a dust wipe sample from an interior windowsill, and the result is 105 μg/ft2. Would clearance pass or fail? Check the correct answer in the Answer Key below.

Reporting

  • A clearance examiner is required to submit a report following clearance activities for abatement projects. Read DHS 163 to learn about when the clearance report is due and which information to include.
  • The HUD Guidelines show what to include in a clearance report:

Answer Key

  • Practice answer: 8 μg/ft2 for an interior floor passes clearance because it is less than 10 μg/ft2. In other words, the level of lead dust is below the clearance standard for floors.
  • Practice answer: 110 μg/ft2 for an interior windowsill fails clearance because it is equal to or greater than 100 μg/ft2.

Quiz

Glossary

 
Last revised April 16, 2026