May have been published by TSR, definitely a smaller (US — maybe game-related) publisher trying to establish itself. I think the novel even opens with the scene where the protagonist gets his “suit,” which invades his nasal passages and mouth and forms a protective barrier. Everyone in the service (society?) gets this suit. It may have been symbiotic organism, not unlike Venom (Spiderman) or the symbiotic suit in Their Master’s War by Mick Farren — except this one was clear.
Standard paperback, aimed at adults, may have had a white cover. Mid-1980s to mid-1990s. Used to see it in used bookstores a lot.