Are you correctly replacing your moisture barrier?

Your moisture barrier’s primary job is to prevent any liquid or blood borne pathogens from penetrating the thermal liner, the inner most layer of the turnout. The moisture barrier, to ensure liquid tight integrity, must have every seam tape sealed to pass both the liquid and viral penetration tests, performance requirements of NFPA 1971 when it is manufactured. What makes a moisture barrier so fragile is its orientation (sandwiched between the outer shell and thermal liner). Abrasion caused by friction of movement across the layers wears the membrane out quickly. This is why for greater safety and protection, moisture barriers must be inspected regularly and also why they often need to be replaced well before the end of a turnout’s life cycle.

The correct way to replace a moisture barrier is to replace it entirely,including its attachment points (snaps, zippers, hook and loop, etc.). The manufacturer or clean and repair center should make a new moisture barrier from the original pattern and then tape seal every seam. The incorrect way, which is lower in cost, is to cut out the existing barrier along the attachment points (see above picture) and stitch the new barrier to the remnants of the old barrier. Often when a moisture barrier is replaced with this method, the new seam is not tape sealed where the new barrier meets the leftover, old barrier. This inferior repair method could compromise the liquid tight integrity of the moisture barrier, potentially allowing water or pathogens to penetrate the barrier through the stitching and is hardly worth the savings (about $100 per garment).

Even though NFPA 1971 certification applies only to new turnouts you should make certain any replacement moisture barriers are complete and professionally taped using either the original manufacturer or a Verified ISP. A cleaning and repair professional can also use the hydrostatic pressure test to assure “as new” performance of the replacement barrier before the turnout is put back into service.