No, OSHA does not specifically require employees to use personal fall protection on portable ladders. However, if employees are working from a portable ladder near an edge, and would be in a situation that makes other fall protective measures inadequate, then additional measures may be needed. For example, if an employee is working from a portable ladder near a guardrail, and a fall from the ladder would likely cause the employee to also fall over the guardrail, then other fall protection measures should be used.