When is a reward a bribe? OSHA policy limits workplace safety incentive programs
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.