According to the Environmental Protection Agency (EPA), hazardous waste is generally classified into four main categories:

1. Characteristic Wastes: These exhibit at least one of four hazardous traits: ignitability (flammable, like gasoline), corrosivity (can rust or decompose materials, like car batteries), reactivity (unstable and can explode, like aerosol cans), or toxicity (harmful when ingested, like lead-based paint).

2. Listed Wastes: These are specific wastes from manufacturing and industrial processes that the EPA has officially designated as hazardous. They include byproducts from processes that use solvents, pesticides, and other chemicals.

3. Universal Wastes: These are commonly generated hazardous items that are subject to streamlined regulations. Examples include batteries, pesticides, mercury-containing equipment (e.g., bulbs), and some lamps.

4. Mixed Wastes: This category includes waste that contains both hazardous and radioactive components, making it subject to regulation by both the EPA and the Nuclear Regulatory Commission.

Properties should be tested for lead every 2-3 years, especially if they are older, have undergone renovations, or show deterioration of paint or interior finishes.

You can expect to pay between $200 and $400 for a lead inspection, where your local lead testing pro will scan surfaces and items with an X-ray fluorescent analyzer. Lead risk assessments are slightly different and run around $800 to $2,000. A pro may find lead during an evaluation, and create a removal strategy.

While not all homes built before 1978 contain lead paint, enough do, so you’ll still want to test to be on the safe side. The federal government banned lead-based paint for homes in 1978, but your state may have banned lead before that time. Around 24% of homes built between 1960 and 1977 contained lead-based paint, while 87% of homes built before 1940 contained lead-based paint.