The best disposal method for hazardous waste is recycling or donation, if possible. That way, the world can reduce its consumption of raw materials and the volume at which materials have to be treated and disposed of. If recycling or donation is not an option, most waste can be disposed of through landfills or incinerators, but their collection and treatment are separate from regular day-to-day waste disposal. 

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.

The EPA enforces hazardous waste laws and ensures people dispose of their hazardous waste responsibly. Depending on where you live, your state’s hazardous waste regulatory agency may also enforce these laws. Individually, it’s up to each household to properly dispose of their hazardous waste.

Lead toxicity comes from inhaling lead or consuming it. Before the 1980s, when the government banned lead from consumer use, it could be found in paint, plumbing, pipes, ceramics, and even gasoline. Lead paint is toxic for the same reason lead itself is toxic, which is why lead poisoning from paint presents the same as lead poisoning from water or food sources, with a slight increase in respiratory symptoms vs. digestive symptoms. Lead paint is most dangerous when it’s old and peeling, cracking, or otherwise disturbed. This increases the concentration in the air and, therefore, in breathable air.