Odds of Hanging On
To put it in simple terms, once you're in, you're pretty much in. Don't get us wrong, it's not the mob—there's no blood oath, and if you screw up, you get sacked, not whacked.
Regardless of whether you're more on the research side or the manufacturing end of things, there are different factors (i.e. technological progress, new regulations) that may make certain industry jobs redundant from time to time. That said, as long as you stay on top of the latest in the field and keep from becoming obsolete yourself, you ought to be alright.
Even if you manage a factory or research flash-freezing methods for a company that goes belly-up, your skill set is still very sought-after. Throw out a few applications, schmooze up some of those industry contacts you've made over the years, and bam—you'll be back on your feet in no time.