Mixture Rule

Mixture Rule in the United States

Mixture Rule in Environmental Law

A principle created by the Environmental Protection Agency (EPA) to prevent people from diluting hazardous waste in order to avoid regulation. The EPA’s standard motto in this area is “the answer to pollution is not dilution.” According to this rule, if a hazardous waste is mentioned by name in the EPA regulations, adding any other substance to it results in a mixture that is also a hazardous waste.

The mixture rule, as well as the derived from rule, was invalidated in the case of Shell Oil Company v. Environmental Protection Agency. Later the Environmental Appeals Board determined that the effect of the Shell Oil decision was to erase the two rules from the time they were created in 1980 until reinstatement by emergency rule on 3 March 1992. The case before the Environmental Appeals Board was In the Matter of Hardin County (1994).
Based on “Environment and the Law. A Dictionary”.

Mixture Rule: Open and Free Legal Research of US Law

Federal Primary Materials

The U.S. federal government system consists of executive, legislative, and judicial branches, each of which creates information that can be the subject of legal research about Mixture Rule. This part provides references, in relation to Mixture Rule, to the legislative process, the federal judiciary, and the primary sources of federal law (cases, statutes, and regulations).

Federal primary materials about Mixture Rule by content types:

Laws and Regulations

US Constitution
Federal Statutory Codes and Legislation

Federal Case Law and Court Materials

U.S. Courts of Appeals
United States courts of appeals, inclouding bankruptcy courts and bankcruptcy appellate panels:

Federal Administrative Materials and Resources

Presidential Materials

Materials that emanate from the President’s lawmaking function include executive orders for officers in departments and agencies and proclamations for announcing ceremonial or commemorative policies. Presidential materials available include:

Executive Materials

Federal Legislative History Materials

Legislative history traces the legislative process of a particular bill (about Mixture Rule and other subjects) for the main purpose of determining the legislators’ intent behind the enactment of a law to explain or clarify ambiguities in the language or the perceived meaning of that law (about Mixture Rule or other topics), or locating the current status of a bill and monitoring its progress.

State Administrative Materials and Resources

State regulations are rules and procedures promulgated by state agencies (which may apply to Mixture Rule and other topics); they are a binding source of law. In addition to promulgating regulations, state administrative boards and agencies often have judicial or quasi-judicial authority and may issue administrative decisions affecting Mixture Rule. Finding these decisions can be challenging. In many cases, researchers about Mixture Rule should check state agency web sites for their regulations, decisions, forms, and other information of interest.

State rules and regulations are found in codes of regulations and administrative codes (official compilation of all rules and regulations, organized by subject matter). Search here:

State opinions of the Attorney General (official written advisory opinions on issues of state law related to Mixture Rule when formerly requested by a designated government officer):

Tools and Forms

Law in Other Regions

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