"Right to know" empowers "people by allowing them to participate in an informedway in decisions that affect them, while also holding governments and others accountable". It pursues universal access to information as essential foundations of inclusive knowledge societies.

In the context of United States workplace and community environmental law, it is the legal principle that the individual has the right to know the chemicals to which they may be exposed in their daily living. It is embodied in federal law in the United States as well as in local laws in several states. "Right to Know" laws take two forms: Community Right to Know and Workplace Right to Know. Each grants certain rights to those groups. The "right to know" concept is included in Rachel Carson's book Silent Spring.

Environmental illness shares characteristics with common diseases. For example, cyanide exposure symptoms include weakness, headache, nausea, confusion, dizziness, seizures, cardiac arrest, and unconsciousness. Influenza and heart disease include the same symptoms. Cyanide is one of the most toxic known substances, and failure to obtain proper disclosure is likely to lead to improper or ineffective medical diagnosis and treatment. This can contribute to prolonged illness and death.