Many (not all, maybe not even most, but definitely a good amount) libertarians are environmentalist and see the EPA as a valuable tool to ensure that people's rights are violated.
However, in general the cause is the same but the approach is different. For example, just of those two causes should be handled by the courts (as a libertarian sees it at least) rather than through regulatory agencies.
To rephrase, Libertarian's generally agree people should be safe at work. They just disagree with the top down approach to solving that issue.
In certain narrow situations where there is an identifiable property right at issue (e.g. dumping waste on private land). But there aren't a lot of libertarian theorists espousing a general "right" to untouched wilderness, preserving endangered species, or having clean rivers.
> To rephrase, Libertarian's generally agree people should be safe at work.
Libertarians generally believe that the level of safety in the workplace should be set by the market, rather than by a regulatory agency. I.e. if a workplace is known for being unsafe, it won't be able to hire employees (or will have to pay a premium for employees to take on the extra risk). Liberals in contrast believe that the government should impose a safety floor on all workplaces, irrespective of the market.
To me, this is where the libertarian philosophy loses its internal consistency. For two reasons:
1) There is no such thing as a closed system, so land use is fundamentally social
2) For the most part, all existing property deeds were obtained by force, not through the voluntary agreeing to contracts, so no one who holds a deed really has any kind of moral claim on it.
Libertarians have to fall back on some other political system (manifest destiny, kraterocracy, democrasy, etc) to resolve the land use question. But to me land use is the foundation of all property law and the fact that Libertarianism has nothing to say about it makes it largely useless as a foundational political system. It's a nice thing to think about, but it can't be relied on to answer basic questions.