The “100 week rule” comes from Section 301(5)(e) of the Workers Disability Compensation Act:
"If an employee, after having been employed pursuant to this subsection for less than 100 weeks loses he or her job for whatever reason, the employee shall receive compensation based upon his or her wage at the original date of injury."
What it means is that if employee who has sustained a work related injury and who has returned to “reasonable employment” stops working “for whatever reason”, then that employee is entitled to continued wage loss benefits.
So if someone is hurt at work and then comes back to restricted-reasonable work, and works in a restricted capacity less than 100 weeks (2 years), that person is entitled to wage loss benefits when they stop working. The employee needs to be under restrictions when they stop working. The employee is paid wage loss benefits based on the original date of injury. Further, the employee is entitiled to the accelerated, "60 day" status on his or her petition. "60 day" status only means that the petition gets higher priority than other petitions.
It has been successfully argued that in the event that an employee tests positive for drugs during that 100 weeks, that the employee will not obtain wage loss benefits because he or she had refused the offer of "reasonable employment". Testing positive for drugs has the same effect as a voluntary removal from employment.