Environmental jobs are going to be very entry level, repetitive, and low pay, but maybe best chance right now. Any experience whatsoever?
If in Houston area, there are lots of chemical and petrochemical companies but market is tight. Lyondell, Shell, Chevron, Exxon, Valero. There are a few 3rd party testing labs in Pasadena like Bureau Veritas, Amspec, SGS, but those places can be meat grinders for folks. I have less experience but there are oilfield service companies such as Haliburton or Schlumberger, or water treatment such as Nalco or ChampionX.
If looking at Pharma, check out Eagle Analytical in Sugarland. Eli Lilly is building a new campus in NE Houston, but are mostly looking for PhD and experienced hires for now.
Austin, its more tech than chemistry. Quite a few semiconductor and semiconductor adjacent companies. Samsung, Entegris, Tesla.
Can't speak for Dallas area.