Is impairment the same as being over the limit?

Impairment and being over the limit are related concepts but not the same. Impairment refers to a decline in mental or physical abilities, often due to substances like alcohol or drugs, which can affect a person's capacity to perform tasks safely. Being over the limit specifically refers to exceeding legal blood alcohol concentration (BAC) thresholds set by law, which can indicate impairment but doesn't encompass all forms of impairment that might occur at lower BAC levels or from other substances.