EPA is the short name people in the United States use for the Environmental Protection Agency — the national office that watches air, water, land, and chemicals, and writes rules to keep them safer. When an American says “the EPA”, they almost always mean this one US government body, not a general idea and not every country’s environment office. Other places use other names; in Taiwan people have long said 環保署 for the local one, and that office is now the Ministry of Environment (環境部), though the old short name still turns up in speech. The same three letters can mean other things in a science class (for example a kind of oil from fish), but this entry is the government agency. It is a formal name, yet it shows up in news, protests, and ordinary talk whenever people are angry about pollution.