Risk assessments determine the presence or absence of lead-based paint hazards and suggest appropriate hazard control measures. They can be performed only by certified risk assessors.

To provide the necessary guidance, a risk assessment must cover the following:

• Identification of the existence, nature, severity, source, and location of lead-based paint hazards (or documentation that no such hazards have been identified).
• Presentation of the various options for controlling lead hazards in the event that hazards are found, including interim controls, abatement measures, and any recommended changes to the management and maintenance systems.

In some cases, the risk assessor will provide recommendations beyond the basic lead hazard control options. For example, if lead-based paint will remain in a dwelling after present hazards are corrected, the risk assessor will provide information to the owner on how to keep that paint in a nonhazardous condition.

Risk assessments do not simply identify lead-based paint, but lead-based paint hazards. They assess the condition of paint, taking into account both resident and owner use patterns and management and maintenance practices that will affect that paint. They also identify other potential sources of lead hazards, such as dust and soil. By considering all hazards and examining resident and owner practices, a risk assessor determines appropriate ways to control hazards and to modify management practices so that the chance of hazards recurring is reduced.

Key units of measurement

μg (Microgram): A microgram is 1/1000 th 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 is used to measure the level of lead in children’s blood, to establish whether intervention is needed. A deciliter (1/10 th 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.

Lead based paint standards

Lead based paint is defined as paint or other surface coatings that contain at least:

• 1 milligram per centimeters square (mg/cm 2) 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.

Federal threasholds have been set for Lead in Dust, which are used in clearance inspections and lead hazard risk assessments:

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

Federal thresholds have been set for bare soil acontamination:

• Play areas used by children under age 6 <400 ppm
• Other areas, if more than 9ft² in total <1200 ppm

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