Chemical waste is any excess, unused, or unwanted chemical. Chemical waste may be classified as hazardous waste, non-hazardous waste, universal waste, or household hazardous waste, each of which is regulated separately by national governments and the United Nations. Hazardous waste is material that displays one or more of the following four characteristics: ignitability, corrosivity, reactivity, and toxicity. This information, along with chemical disposal requirements, is typically available on a chemical's Safety Data Sheet (SDS). Radioactive and biohazardous wastes require additional or different methods of handling and disposal, and are often regulated differently than standard hazardous wastes.

The U.S. Environmental Protection Agency (EPA) prohibits disposing of certain materials down drains. Therefore, when hazardous chemical waste is generated in a laboratory setting, it is usually stored on-site in appropriate waste containers, such as triple-rinsed chemical storage containers or carboys, where it is later collected and disposed of in order to meet safety, health, and legislative requirements. Many universities' Environment, Health, and Safety (EHS) divisions/departments serve this collection and oversight role.

Organic solvents and other organic waste is typically incinerated. Some chemical wastes are recycled, such as waste elemental mercury.

During packaging, chemical liquid waste containers are filled to no greater than 75% capacity to allow for vapor expansion and to reduce potential spills that can occur from transporting or moving overfilled containers. Containers for chemical liquid waste are typically constructed from materials compatible with the hazardous waste being stored, such as inert materials like polypropylene (PP) or polytetrafluoroethylene (PTFE). These containers are also constructed of mechanically robust materials in order to minimize leakage during storage or transit.

In addition to the general packaging requirements mentioned above, precipitates, solids, and other non-fluid wastes are typically stored separately from liquid waste. Chemically contaminated glassware is disposed of separately from other chemical waste in containers that cannot be punctured by broken glass.

Containers may be labelled with the group name from a list of chemical waste categories, along with an itemized list of the contents. All chemicals or materials contaminated by chemicals pose a significant hazard, and as such regulations require that the identity of the chemicals in a waste container is obvious.

Chemical waste containers are kept closed to prevent spillage, except when waste is being added. Suitable containers are labeled in order to inform disposal specialists of the contents as well as to prevent the addition of incompatible chemicals. Liquid waste is stored in containers with secure screw-top or similar lids that cannot be easily dislodged in transit. Solid waste is stored in various sturdy, chemically inert containers, such as large, sealed buckets or thick plastic bags. Secondary containment, such as trays or safety cabinets, are used to capture spills and leaks from the primary container and to segregate incompatible hazardous wastes, such as acids and bases.

Many chemicals react adversely when combined. Incompatible chemicals are therefore stored in separate areas of laboratories.