Being a Dental Hygienist after undergrad years

So I’m going to be a junior at UC Berkeley as a pre-dental student, but I have been thinking about being a dental hygienist as a backup plan. I know I would graduate with a Bachelors of Science degree from Molecular Environmental Biology, so I was wondering what else would it take to be a dental hygienist if dentistry doesn’t work? Berkeley doesn’t have a dental hygienist program.