OSHA Danger Safety Sign: Lock Out Equipment Before Entering. Remind employees that equipment must be locked out prior to entry. Remind workers of lockout protocols in the workplace in order to prevent injury. Post near hazardous equipment where lock out protocols can prevent potentially fatal accidents. Traditional OSHA-style signs, tags and labels are the most widely recognized design format in the industry. Danger header indicates a hazardous situation that, if not avoided, will result in death or serious injury.