Is terro ant killer poisonous to humans?

Terro ant killer contains borax, which is considered low in toxicity to humans when used as directed. While it can cause irritation if ingested or if it comes into contact with skin, serious harm is unlikely in small amounts. However, it's always best to follow safety instructions on the label and keep it out of reach of children and pets. If ingestion occurs, it's advisable to seek medical attention.