For this question, I am interested only in the aspect of handling the chametz and "benefitting" from it on Hol Hamo'ed, not any problems, possibly of going to work. (Let's assume that if the worker doesn't appear, he will be fired.)
The person's responsibility is to perform chemical tests on chametz food items. A certain quantity of chametz samples remains in his work fridge, so it is, technically, in his work "property" area, though, the company owns the fridge and pays for all the samples. The worker, of course, gets a salary via studying the chametz.
Is the fact that he handles and gets a salary studying chametz considered within the prohibition of "deriving benefit" from chametz, or is it not since the chametz never belongs to him.
Also (possibly) in this equation - because of the nature of the research, in most cases, chemicals and other processing (such as centrifuging and heating) usually render the food inedible almost immediately.
Based on comments: - The question is not restricted to only this specific job, but any job where chametz may need to be handled as part of research studies, including a professional chef or baker at a non-Jewish place.
I have included the chef and baker based on this assumption - it is not your chametz. Never bought or owned by you and will never be eaten or used by you. How would this be different from going to the supermarket on Hol Hamo'ed, picking up a package of matzot and looking at the label to see the words "Not for Passover use"?