We have heard that some employees aren't sanitizing their workstations and wearing masks when required. Do we need to investigate safety violations even if no one has made an official complaint?
It is recommended you investigate the matter and take appropriate enforcement or disciplinary action.
As an employer, you have an obligation under the OSHA general duty clause to provide a workplace free from hazards. Under the circumstances, this may mean requiring that employees wear face coverings in the workplace and complete additional cleaning and disinfecting protocols to prevent spread of COVID-19.
If you don’t already have a written policy in place regarding safety and PPE requirements, I suggest issuing one now and having all employees sign an acknowledgment of receipt of the policy. I also recommend notifying employees that they will be held accountable to the policy and can be disciplined regardless of whether they sign it.