Applied to occupational health and safety, due diligence means that that the employer/owner shall take all-reasonable precautions, under a particular set of circumstances, to prevent injuries or accidents in the workplace.Due diligence is important as a legal defense for an employer/owner charged under occupational health and safety legislation. If charged, a defendant may be found not guilty if he or she can prove that due diligence was exercised. In other words, the defendant must be able to