Under the authority of the Professional Engineers Act, PEO governs over 91,500 licence and certificate holders and regulates the practice of professional engineering in Ontario. PEO’s mission is to regulate and advance the practice of engineering to protect the public interest. Its vision is to be the trusted leader in professional self-regulation. Professional engineering safeguards life, health, property, economic interests, the public welfare and the environment. Professional engineers can be identified by the P.Eng. after their names. Holders of limited licences can be identified by LEL or LET after their names.