The Workplace Safety and Insurance Act, 1997, S.O. 1997, c. 16, Sched. A. (WSIA) contains some important provisions which may act to preclude a plaintiff from bringing a claim against certain defendants. Under s.28(1) of the WSIA, a worker employed by a Schedule 1 employer, the worker’s survivors and a Schedule 1 employer are not entitled to commence an action against any Schedule 1 employer or its employees. While it may seem safe to assume that an employer falls under Schedule 1 based on their industry, the devil can be in the details. Some employers are deemed to be Schedule 1 on a compulsory basis while others are deemed Schedule 1 by application only. Unfortunately, this distinction is not always obvious. For example, employers involved in “Cable Television” are deemed compulsory under Schedule 1 while those involved in “Television Broadcasting” are Schedule 1 by application only. The “Employer Classification Manual”, published by the Workplace Safety and Insurance Board (WSIB), is helpful in classifying the business activities of employers. This resource can be used in conjunction with the WSIB’s “Operational Policy Manual” to determine whether a right to sue application is likely to be successful.