I think the fact is where you made mention of implement procedures to ensure only authentized personnel can enter in the lab, i the company should also consider posting caution signs to alert individuals of the sensitive nature of the lab this could also be of help too, pulses always ensure throughful screening of staff and visitors before gaining access to the lab. Prioritizing lan security services that can protect sensitive information assets and personal data of clients
Personally I don't see the reason why outsiders should be allowed in a lab, regardless of their intentions bringing them into the lab is a security risk one way or the other, people can cause harm without intended for it to happen, this usually occurs when in an unfamiliar environment, this is almost the same thing that happens with newly employed, called 'rookie mistake' but an employed personnel will have knowledge on how the lab operates, an outsider might as well be an alien to the environment.