Hazardous waste

• DEFINITION: Waste products of industrial society that pose dangers to human health and the environment

Although many national governments have taken steps to regulate the disposal of hazardous wastes, some have not, and many such wastes continue to be produced all over the world. Improper disposal of hazardous wastes creates serious problems for the environment.

In the United States, hazardous wastes are legally defined as materials that have ignitable, corrosive, reactive, or toxic properties. In the early 1990s, approximately 97 percent of all hazardous waste in the United States was produced by 2 percent of the waste generators and in 2023, the US generated approximately 32.23 million tons of hazardous waste from large quantity generators. Remediation and cleanup of these wastes involved substantial economic cost. Since the 1970s, the United States and other industrialized nations have tried to regulate hazardous waste disposal. Hazardous wastes have historically been a serious problem in Russia and other Eastern European nations, though ongoing environmental reforms and international cooperation have addressed some legacy issues.

Environmental Problems

Improper disposal of hazardous waste can lead to the release of chemicals into the air, surface water, groundwater, and soil. High-risk wastes are those known to contain significant concentrations of substances that are toxic, persistent, mobile, or bioaccumulative. Examples include dioxin-based wastes, polychlorinated biphenyls (PCBs), and cyanide wastes. Intermediate-risk wastes may include metal hydroxide sludges, while low-risk wastes are generally high-volume, low-hazard materials. Radioactive waste is a special category of hazardous waste, often presenting extremely high risks, as do biomedical and mining wastes.

Hazardous waste presents varying degrees of health and environmental hazards. When combined, two relatively low-risk materials may pose a high risk due to chemical interactions that create more hazardous substances. Factors that affect the health risk of hazardous waste include the dose received; the age, gender, and body weight of those exposed; and weather conditions. The health effects posed by hazardous waste include cancer, genetic defects, reproductive abnormalities, and central nervous system disorders.

Environmental degradation resulting from hazardous waste can render various natural resources, such as croplands and forests, useless and can harm animal life. For example, chemicals can leach out of improperly stored waste and into groundwater. Hazardous wastes may also generate long-lasting air pollution, water pollution, or soil contamination. In the past, before standards were in place for managing hazardous wastes, such materials were often buried or stored in unattended drums or other containers. This situation created threats to the environment and human health when the original containers began to leak and the materials leached into the soil and the water supply.

Methods for Handling Wastes

The technologies and methods used in dealing with hazardous solid and liquid wastes continue to evolve. Several approaches have had positive impacts on the environment and the consumption of natural resources. One is the reduction of the volume of waste material through efforts to generate less of it. Another approach is to recycle hazardous materials as much as possible. A third means of dealing with hazardous waste is to treat it to render it less harmful; often, such treatment also reduces its volume. The least desirable among methods of addressing the problem is the storage of hazardous wastes in landfills. The Environmental Protection Agency (EPA) has established standards for the responsibility and tracking of hazardous wastes, based on the principle that waste generators are responsible for their waste “from cradle to grave.” This principle requires that waste generators and disposal sites keep extensive records. Federal regulations have expanded reporting requirements by increasing the number of per- and polyfluoroalkyl substances (PFAS) subject to Toxics Release Inventory reporting and requiring suppliers to notify of their presence.

The costs for the cleanup and remediation of hazardous waste are substantial and are likely to continue to grow. This situation is particularly true in Eastern Europe and the nations of the former Soviet Union, where the magnitude of past dumping of hazardous materials is slowly becoming apparent. Meanwhile, some less industrialized nations continue to face challenges in managing hazardous waste, although many are developing regulatory frameworks and receiving international support.

US Legislation

The 1984 amendments to the federal Resource Conservation and Recovery Act (RCRA) included a thorough overhaul of hazardous waste legislation. Previously exempt sources that generated between 100 and 1,000 kilograms (220 and 2,200 pounds) of hazardous waste per month were brought under RCRA provisions. Congress further tried to force the EPA to adopt a bias against the landfilling of hazardous waste with a “no land disposal unless proven safe” provision. The amendments also added underground storage tanks for gasoline, petroleum, pesticides, and solvents to the list of sources to be regulated and remediated. In addition to RCRA, the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (known as Superfund) provides for the cleanup of all categories of abandoned hazardous waste sites except for radioactive waste sites. In the 2020s, Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were designated as hazardous substances under federal law, expanding cleanup liability and reporting requirements. Several other statutes (and ensuing EPA regulations) have dealt with these aspects of the hazardous waste problem. The cleanup of existing sites remains a troubling problem, while the cleanup and disposal of radioactive waste will be a major issue for the future.

The waste-minimization philosophy expressed in RCRA is a sound long-range strategy for dealing with hazardous waste. However, some materials will continue to be deposited in landfills. Incineration offers one solution to the problem of material volume, but poses issues of air quality and disposal of the highly toxic ash remaining. As some firms have found, minimizing their waste stream affords them economic benefits while conserving natural resources.

Household waste, which is not regulated by RCRA, often includes small quantities of hazardous materials such as pesticides. Many of these materials continue to be landfilled, as individual consumers may lack awareness of proper disposal methods or access to appropriate facilities.

Bibliography

“EPA’s PFAS Rulemaking Trajectory: Key Updates Across CERCLA, TSCA, RCRA, SDWA and CWA.” Holland & Knight, 7 Oct. 2025, www.hklaw.com/en/insights/publications/2025/10/epas-pfas-rulemaking-trajectory-key-updates. Accessed 14 Apr. 2026.

Erickson, Britt E. “EPA Designates PFOA and PFOS as Hazardous Substances.” Chemical & Engineering News, 22 Apr. 2024, cen.acs.org/environment/persistent-pollutants/EPA-designates-PFOA-PFOS-hazardous/102/web/2024/04. Accessed 16 Apr. 2026.

Ferrell, Jessica K., et al. “EPA Backs PFAS Hazardous Substance Designation Under CERCLA.” Marten Law, 29 Sept. 2025, martenlaw.com/news/epa-backs-pfas-hazardous-substance-designation-under-cercla. Accessed 14 Apr. 2026.

Fletcher, Thomas H. From Love Canal to Environmental Justice: The Politics of Hazardous Waste on the Canada-U.S. Border. Broadview Press, 2003.

Grisham, Joe. Health Aspects of the Disposal of Waste Chemicals. Pergamon, 1986.

Hill, Marquita K. “Hazardous Waste.” Understanding Environmental Pollution. 3rd ed., Cambridge University Press, 2010.

LaGrega, Michael D., et al. Hazardous Waste Management. 2nd ed., McGraw-Hill, 2001.

McKinney, Michael L., et al. “Municipal Solid Waste and Hazardous Waste.” Environmental Science: Systems and Solutions. 4th ed., Jones and Bartlett, 2007.

So, Won. “Hazardous Waste Produced by the Largest Generating States in the United States in 2023.” Statista, 20 Jan. 2026, www.statista.com/statistics/1267166/hazardous-waste-generation-in-the-united-states-by-state/. Accessed 16 Apr. 2026.

“Superfund.” US Environmental Protection Agency, 14 Feb. 2025, www.epa.gov/superfund. Accessed 14 Apr. 2025.