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.

Disposing of old paint, bleach, oil, and fertilizer should be handled by a company that specializes in this kind of waste. Many private junk removal companies do not dispose of these items. Because these materials are hazardous to the environment and dangerous to handle or dispose of improperly, you should confirm with your local municipality about places to take hazardous materials for safe disposal. 

You can paint over lead paint, or “encapsulate” it with a special paint that includes an ingredient called an encapsulant. The EPA approves encapsulation as a lead paint removal method as long as the paint remains undisturbed. Standard types of paint without an “encapsulant” from the big box stores or hardware stores do not meet EPA standards for remediation of lead-based paint.

By using PPE, sealing work areas, and following containment procedures.