This is tricky, really. Ultra fine contaminate is basically beyond the scope of most rugged gear. The problem I see here is that in these types of environments it will be very difficult to operate any type of machine requiring ventilation. If an air current can penetrate the gear, it is more than likely that fine contaminates will penetrate the gear. I'm not aware of any surfaces that are permeable by gas but not microscopic contaminate without a dramatic filter system. I think the solution(long term) that you might look at will be to use a portable "safe room" on the cheap. Setting up a safe environment will take extra time, and training, but what you might save in hardware and productivity may justify the cost. I guess it might largely depend on the steps to interface with machines(stairs, narrow walkways, tarzan ropes) however I could envision a reusable portable sterile room. I imagine that hardware users are probably a HUGE part of why micro contaminates enter the hardware, since they are on every inch of a user long before they penetrate the hardware, the more a "dirty" user touches of interfaces with hardware components, the worse it gets. This seems deeper than a simple manufactured solution.