PI’s are the single most important element for developing and sustaining a strong, proactive laboratory safety culture and must clearly communicate and reinforce to everyone within their groups that safety within their research laboratory is a top priority and define roles, responsibilities, authority and accountability for safety within their laboratory.
It is FAR easier to make a practice routine than to be "fixing" problems after the fact.
An initial "spring cleaning" to get your lab and people on board is highly recommended.
All labs accumulate "legacy" messes from people who have left and no one here currently wants to take responsibility for.
SEE: Supervisor Health and Safety Responsibilities : EHS-5400 in STARS