The CSB hasn't been shuttered yet and the chemicals industry is fighting this hard. I am pretty involved with industry groups and everyone is telling each other to call their representatives to fight this. Shuttering the CSB does not help chemical companies - they are not a regulatory agency and can't issue fines or anything. All they do is investigate incidents give recommendations for how to avoid similar incidents. This is effectively a free service for chemical manufacturing companies, and even from an evil capitalist perspective, the types of incidents investigated by the CSB cost a LOT of money and can easily bankrupt small or medium sized companies, and seriously harm big ones. A plant exploding is not good for business because that plant is not making any money any more. The types of safety incidents that companies make money not preventing are the minor ones, like a guy getting an arm cut off by a motor or dying from a fall. Major incidents like those covered by the CSB are bad even if you're a heartless capitalist who doesn't care if people die.
This is pure stupidity that only hurts people AND businesses, and benefits no one except maybe industrial insurers who can charge for investigations? But even then they benefit from the government doing it for free so idk who could possibly benefit from this. My guess is it's short-sightedness from DOGE morons who saw a government agency that doesn't "do anything" and wanted to cut it. Even by Trump standards this is completely idiotic. I haven't seen anyone get a response to any of their letters but I won't be surprised if they're completely ignored.
Then again, the chemicals industry has been disproportionately fucked by the tariffs and Trumpian "protectionism" directly harming a sector that still makes a lot of stuff in the USA. Maybe it's because Tech has deeper pockets or they truly don't care about corporate interests, but the chemicals industry is reaping what they've sowed here because all the big dogs supported all this shit through PACs and are getting completely fucked over.