Acid-resistant packing

Acid-resistant packing is a type of industrial sealing material (typically braided rope, sheet gasket, or molded form) designed to seal pumps, valves, flanges, and reactor vessels that handle corrosive acids and chemicals. From roughly the 1920s through the 1980s, much of this packing was made with asbestos fibers (chrysotile, crocidolite, or amosite) because asbestos resisted acid attack, heat, and pressure better than most alternatives. Workers who installed, replaced, or removed this packing were often exposed to airborne asbestos fibers.

Origin

The term comes from the industrial sealing trade, where "packing" historically referred to fibrous material compressed into a stuffing box to prevent leaks. Acid-resistant grades emerged with the growth of the chemical and petrochemical industries in the early 20th century, and asbestos-reinforced versions became standard after manufacturers like Garlock, John Crane, and Anchor Packing introduced branded product lines in the 1920s–1930s.

Significance in Asbestos Context

Acid-resistant packing is one of the most commonly identified exposure sources in claims brought by chemical plant workers, refinery workers, paper mill employees, pulp mill workers, and pipefitters. The packing had to be cut to length, pounded into stuffing boxes, and later dug out when worn. Each of those steps released visible dust. Major manufacturers including Garlock Sealing Technologies, John Crane Inc., and Anchor Packing Company faced extensive litigation over these products, and several established bankruptcy trusts that still pay claims today. Identifying the specific brand and grade of packing used at a worksite can be critical to recovering from the right trust or defendant.

Example Sentence

His work history showed thirty years as a millwright replacing acid-resistant packing in pump glands at the paper mill, which his attorney identified as a primary exposure source.

Related Terms

Gaskets, Chrysotile, Garlock Bankruptcy Trust, Pipefitter exposure, Stuffing box, Anchor Packing

Notes

• If you or a loved one worked with packing, try to recall or document brand names (Garlock, John Crane, Anchor, Palmetto, Chesterton) and the colors or styles used. This directly affects which trusts may pay.
• Preserve any old work records, union books, purchase orders, or coworker contact information that can establish which products were present at the jobsite.
• Ask coworkers whether packing was cut dry with a knife or saw, and whether old packing was dug out with picks. Both practices generated heavy fiber release and strengthen exposure testimony.
• Chemical plant, refinery, pulp/paper, and Navy shipyard workers should specifically mention packing exposure when giving an occupational history to their doctor and legal team, as it is often overlooked in favor of insulation.