Question: What does the term “signal word”, as used by U.S. EPA, signify?
Answer: “Signal words” are the words used on a pesticide label- Danger, Warning, Caution- to indicate level of toxicity. Signal words “describe the acute (short-term) toxicity of the formulated pesticide product. The signal word can be either: DANGER, WARNING or CAUTION. Products with the DANGER signal word are the most toxic. Products with the signal word CAUTION are lower in toxicity. The U.S. Environmental Protection Agency (EPA) requires a signal word on most pesticide product labels. They also require it to be printed on the front panel, in all capital letters, to make it easy for users to find. The only pesticide products that are not required to display a signal word are those that fall into the lowest toxicity category by all routes of exposure (oral, dermal, inhalation, and other effects like eye and skin irritation).(https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&glossaryName=Terms%20of%20Env%20(2009)#formTop; accessed December 2016 and http://www.npic.orst.edu/factsheets/signalwords.pdf; accessed December 2016)