Questions about the video will likely shadow Republican Vivek Ramaswamy, a biotech billionaire who previously ran for president but has never before held public office, in the final two weeks of the contest.

In Cincinnati, the vice president said it was "not really my concern" whether the controversial 60-second spot was appropriate, and said he was focused on supporting Republican candidates in their midterm races.

People who come into contact with glycidyl methacrylate may feel as if their eyes, nose, mouth and skin are burning, the city fire department said. Overexposure can lead to headache, dizziness, tiredness, nausea and vomiting.