I wonder - how exactly does this work?
For all I know, service dogs primarily help blind people or those with severe mental health issues.
The former must make working in a lab near impossible as most things are observed visually and also making an organized spot for a blind researcher must require thorough preparation and heavy assistance for every experiment. The latter might behave unpredictably, which doesn't pair well with a lab environment, and might prompt the dog to rush to support without minding the environment, amplifying the issue.
Also, dog is an animal, and while they can be trained to behave well, they are unlikely to remember all safety rules, especially in a critical situation where they need to focus on aiding the owner.
I might be wrong by all points, since I didn't ever see service dogs in a lab environment, and don't commonly see them around, but I come from a point of genuine interest.