2. Some wastes may be exempted from hazardous waste classification for disposal purposes only if certain conditions are met. These wastes must be considered hazardous only because the total concentration of regulated chemicals present in the waste exceeds the Total Threshold Limit Concentration. When dealing with these wastes, generators must follow predisposal hazardous waste management requirements in the regulations adopted by the DTSC if applicable. This does not apply to liquids, sludges, sludge-likes, soils, finely divided or tarry materials, or organic chemicals.

Other statutory exclusions/exemptions:

• Geothermal drilling wastes  
• Mining wastes (subject to TPCA and HSC Chapter 6.8)    
• Treated wood wastes (exclusively from electric, gas or telephone service) must be disposed of in a landfill that is authorized to accept treated wood wastes
• Cementitious materials (cement, cement kiln dust, clinker, clinker dust) are not required to be tested for solid corrosivity, and if they are hazardous solely due to corrosivity for solids, they are excluded from classification
• Petroleum contaminated debris, such as wood, paper, textiles, concrete rubble, metallic objects, and solid manufactured objects are not federally regulated and do not contain free liquids. They must be disposed of in a hazardous waste (Class I) landfill or landfill authorized to accept certain types of hazardous waste allowed by the Regional Water Quality Control Boards (e.g., Class II landfill)
• Asbestos wastes may be disposed of in a non-Class I landfill.    
• Biohazardous waste, such as formaldehyde fixed human surgery specimens or tissues, wastes contaminated with chemotherapeutic agents, and pharmaceuticals