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.

Professional lead-paint abatement companies use a variety of methods to remove lead-based paint, depending on each particular situation. Some of the most common methods include:

• Total removal: $8–$17 per square foot

• Demolition and replacement: $1,000–$15,000 per project

• Encapsulation: $4 per square foot

• Enclosure: $10 per square foot

• Chemical stripping: $10–$17 per square foot

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. 

While the EPA provides guidelines for homeowners to perform DIY lead paint removal, it is a risky process and generally not recommended due to serious health risks and strict regulatory requirements. The process requires precise safety precautions, such as wearing a respirator and protective eyeglasses, creating sealed exits, and using a HEPA vacuum for cleanup. To ensure the job is done safely, effectively, and in compliance with regulations, it is highly recommended to hire a professional lead abatement company. Certified professionals have the necessary training, experience, and specialized equipment (like chemical strippers and HEPA vacuums) to handle and dispose of hazardous materials safely.