Glossary of Terms for Lead Paint, Paint Hazards, Lead Poisoning and Units of Measure

Lead-Based Paint: Paint or other surface coatings that contain lead equal to or exceeding 1.0 milligram per
square centimeter or 0.5 percent by weight or 5,000 parts per million (ppm) by weight.
Lead-Based Paint Hazards: Any condition that causes exposure to lead from dust-lead hazards, soil-lead
hazards, or lead-based paint that is deteriorated or present in chewable surfaces, friction surfaces, or impact
surfaces, and that would result in adverse human health effects.
Visual Assessment: A visual inspection of interior and exterior surfaces to identify specific conditions that
may be lead-based paint hazards. A visual inspection does not identify lead-based paint. The assessment
may be performed by a person trained in visual assessment. Training for visual assessment is available on
HUD’s website at


  • Paint Testing: Testing of specific surfaces, by XRF (x-ray fluorescence) or lab analysis, to determine the

lead content of these surfaces, performed by a certified lead-based paint inspector or certified risk assessor.

  • Lead-Based Paint Inspection: A surface-by-surface investigation to determine the presence of lead-based

paint and the provision of a report explaining the results of the investigation. It is performed by a certified
paint inspector or risk assessor.

  • Risk Assessment: A comprehensive evaluation for lead-based paint hazards that includes paint testing,

dust and soil sampling, and a visual evaluation. The risk assessment report identifies lead hazards and
appropriate lead hazard reduction methods. A certified risk assessor must conduct the assessment.

  • Lead Hazard Screen: A limited risk assessment activity that can be performed instead of a risk assessment

in units that meet certain criteria (e.g. good condition). The screen must be performed by a certified risk
assessor. If the unit fails the lead hazard screen, a full risk assessment must be performed.

  • Clearance Examination: Clearance is performed after hazard reduction, rehabilitation or maintenance

activities to determine if a unit is safe for occupancy. It involves a visual assessment, analysis of dust
samples, and preparation of report. The certified risk assessor, paint inspector, or lead sampling technician
(called a clearance technician in the HUD regulation) performing clearance must be independent from the
entity/individual conducting paint stabilization or hazard reduction.
Paint Stabilization: An interim control method that stabilizes painted surfaces and addressed the
underlying cause of deterioration. Steps include repairing defective surfaces, removing loose paint and
applying new paint.

  • Interim Controls: Set of measures to temporarily control lead-based paint hazards. Interim control

methods must be completed by qualified workers using safe work practices. Follow-up monitoring is

  • Standard Treatments: A complete set of interim control methods that when used together temporarily

control all potential lead hazards in a unit. Because they address all conditions, a risk assessment or other
evaluation is not needed. Standard treatments must be completed by qualified workers using safe work
practices. As with interim controls, follow-up monitoring is needed.

  •  Abatement: Measures to permanently control (i.e., 20 years or more) lead-based paint or lead-based paint

hazards. EPA regulations exclude from the definition of abatement “renovation, remodeling, landscaping or
other activities, when such activities are not designed to permanently eliminate lead-based paint hazards,
but instead are designed to repair, restore, or remodel a given structure or dwelling, even though these
activities may incidentally result in a reduction or elimination of lead-based paint hazards.” [40 CFR 745.223]
Environmental Intervention Blood Lead Level: The level of lead in blood that requires intervention in a
child under age six. This is defined as a blood lead level of 20 µg/dL (micrograms per deciliter) of whole
blood or above for a single test, or blood lead levels of 15-19 µg/dL in two tests taken at least three months

  • µg (Microgram): A microgram is 1/1000th of a milligram (or one millionth of a gram). To put this unit into

perspective, a penny weighs 2 grams. To get a microgram, you would need to divide the penny into 2
million pieces. A microgram is one of those two million pieces.

  • ft² (Square foot): One square foot is equal to an area that has a length of one foot (12 inches) and a width

of one foot (12 inches).

  • µg/dL: Micrograms per deciliter used to measure the level of lead in children’s blood to establish whether

intervention is needed. A deciliter (1/10th of liter) is a little less than half a cup. As noted above, a
microgram is the same weight as one penny divided into two million parts.

  • µg/gram: Micrograms per gram of sample, equivalent to parts per million (ppm) by weight. Used to measure

lead in soil.

  • µg/ft²: Micrograms per square feet is the measurement used to measure levels of lead in dust samples.

The clearance report should have the dust sampling results listed in µg/ft² (micrograms per square foot).
mg/cm2: Milligrams per square centimeter. Used to measure lead in paint.

  • Percent: Percent by weight, used usually for lead-based paint (1 percent = 10,000 µg/gram)
  • PPM: Parts per million by weight, equivalent to µg/gram (10,000 ppm = 1 percent). Used to

measure lead in paint and soil.
Paint – Definition of Lead-Based Paint
Paint or other surface coatings that contain at least:

  • 1 milligram per centimeters square (mg/cm2) of lead;
  • 0.5 percent lead; or 5,000 parts per million lead by dry weight.

*In 1978 the Consumer Product Safety Commission banned the residential use of lead-based paint that contained
greater than or equal to 0.06 percent or 600 ppm of lead
Dust – Federal Thresholds for Lead-Contamination (Risk Assessment/Clearance)

  • Floors 40 µg/ft²
  • Interior window sills 250 µg/ft²
  • Window troughs (Clearance only) 400 µg/ft²

Soil – Federal Thresholds for Bare Soil Contamination

  • Play areas used by children under age 6 400 µg/gram
  • Other areas, if more than 9ft² in total

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