Years ago, my employer gave employees a coaster every quarter that the group had no OSHA reportable incidents. Now it would have been in violation to have such a program. Despite criticism from workers compensation carriers who recognize the benefits of incentive programs, OSHA has reiterated its policy and it continues to enforce against companies that have safety programs that reward on the job safety. Although that is counter-intuitive, it is because OSHA believes that such programs may discourage reporting of reportable injuries and illnesses. OSHA has stated:

Some employers establish programs that unintentionally or intentionally provide employees an incentive to not report injuries. For example, an employer might enter all employees who have not been injured in the previous year in a drawing to win a prize, or a team of employees might be awarded a bonus if no one from the team is injured over some period of time. Such programs might be well-intentioned efforts by employers to encourage their workers to use safe practices. However, there are better ways to encourage safe work practices, such as incentives that promote worker participation in safety-related activities, such as identifying hazards or participating in investigations of injuries, incidents or "near misses." OSHA's VPP Guidance materials refer to a number of positive incentives, including providing tee-shirts to workers serving on safety and health committees; offering modest rewards for suggesting ways to strengthen safety and health; or throwing a recognition party at the successful completion of company-wide safety and health training.

https://www.osha.gov/as/opa/whistleblowermemo.html So employers must be careful as to which behavior they reward.