Asbestos Gaskets and Mechanical Packing

Asbestos gaskets and packing sealed almost every pipe joint, pump, and valve in American industry for most of the twentieth century, and the danger came not from installing them but from tearing the old ones back out. Grinding a single gasket off a flange has been measured at 28.4 fibers per cubic centimeter, which in fifteen minutes puts roughly eight years' worth of ordinary city background air through a worker's lungs¹, and the companies whose products these were recorded much the same figures in their own plants and kept the results to themselves. You don't need to remember which brand you handled or dig up any old records to find out whether you have a claim; if you worked around this material, that's where we start.

Even ordinary city air carries a faint trace of asbestos everywhere, from natural mineral erosion and decades of industrial use, and that trace is the baseline both sides of the panel are measured against.

What these numbers mean. Asbestos in air is measured in fibers per cubic centimeter (f/cc), a unit that hides how dangerous a task was. Across this site we translate each measurement into fibers breathed, feet of fiber end to end, and years of ordinary city air, using conservative, government-sourced assumptions. See how we measure asbestos in air for the method and its limits.

What asbestos gaskets and packing were

A gasket is a flat seal clamped between two flange faces to hold a joint tight; packing is the rope-like or braided material stuffed into the space around a moving shaft in a pump or valve to keep it from leaking. For most of the twentieth century both were made of asbestos, because asbestos held its shape against the heat, pressure, and chemicals that would destroy an ordinary seal. Wherever a pipe carried steam, hot oil, or aggressive chemicals, the seal at the joint was almost always asbestos.

Gaskets came in several forms, and which one a joint used came down mostly to how much pressure and heat it had to survive. The compressed asbestos sheet gasket was the workhorse and the one most workers handled: a sheet of asbestos fiber, binder, and filler that a fitter cut and punched to shape on the job, then clamped between flanges on piping, valve bonnets, pump and compressor housings, heat exchanger heads, and manhole covers across nearly every industry. Higher-pressure and more corrosive joints used metal-bodied designs that still carried an asbestos sealing element: spiral-wound gaskets that alternated asbestos filler with metal windings, metal-jacketed gaskets that wrapped an asbestos core in thin metal, solid ring-joint gaskets with asbestos in the sealing surface, and double-jacketed corrugated gaskets built for the most extreme boiler and refinery lines. The metal hid the asbestos but didn't remove it, and cutting or grinding a spent gasket out released the fiber just the same.

Packing did a different job. Instead of sealing a static joint, it sealed around parts that moved, most often the rotating shaft of a pump, which was the single largest use. Braided or twisted into rope and coiled, it was cut to length, stuffed into the space around the shaft or around a valve stem sliding up and down, and compressed into rings that held back steam, hot oil, or chemicals while the part kept moving. The same rope packing sealed boiler manhole and handhole covers, furnace doors, and the rotating seals on cement, lime, and ceramic kilns. Which packing went where came down to temperature, motion, pressure, and how tight the seal had to be, and the hottest services, like furnace doors and kiln seals, used dry asbestos packing with no lubricant, since anything oily would just burn off.

Representative products and their asbestos content.

These are examples, not a full list:

That last row carries legal significance. "It was only chrysotile, the least dangerous type" is a defense you'll hear, but some gaskets were made with crocidolite, or blue asbestos, the most hazardous fiber of all, so the sealing category was never a chrysotile-only story.

How gaskets and packing put asbestos in the air

Sealed inside an installed joint, a gasket doesn't shed much fiber. The exposure came from taking joints apart, which every maintenance worker did constantly. Years of heat bake a gasket onto the flange faces, so removing it means scraping, wire-brushing, and grinding hardened material off the metal, and each of those methods drives dry, friable (crumbly and dusty) fiber straight into the breathing zone. Pulling dried, degraded packing out of a stuffing box with a hook does the same thing.

Here is what that removal work measured. Each figure is a phase-contrast (PCM) measurement, which counts only the longer fibers and so reads as a floor, not a ceiling:

By the illustrative math on our how we measure asbestos in air page, 15 minutes of grinding a gasket put roughly 8 years of ordinary city air through the lungs. This estimates fibers in the air breathed, not a retained dose.

The full task-by-task story of who did this work, across the trades and the industries, lives on the occupation and industry pages linked below. What belongs here is the product itself and the fact that its danger was designed into how it had to be removed.

What the makers knew

The strongest part of a gasket and packing case is often that the companies documented the hazard themselves and said nothing. This isn't an inference from general industry knowledge; it's on paper, in their own files.

Shell measured it at its own refinery. An internal Shell Wood River industrial hygiene survey in 1985 recorded gasket-removal air at about 28 f/cc², roughly the same measurement later confirmed in independent work-practice studies. Dow Chemical did the same testing with similar results: a 1987 internal Dow measurement of air-powered rotary-tool gasket removal recorded roughly 18 f/cc³. These were the companies' own hygienists, sampling their own workers, writing down numbers hundreds of times the exposure limit, at a time when the workers doing the job were given no warning and no respirator.

That record is why these cases can reach beyond ordinary negligence. When a company measures a hazard in its own plant, files the result, and neither warns the workforce nor changes the work, the conduct supports a claim for gross neglect and, where the law allows, punitive damages.

Who was exposed

Gaskets and packing weren't tied to one trade or one place; they were everywhere a joint had to seal. Rather than retell each worker's story here, this page hands that off to the pages that own it:

• pipefitters and plumbers, whose daily work was breaking joints and repacking valves
• boilermakers and millwrights and machinists on pumps, valves, and rotating equipment
• refineries and petrochemical plants, where turnaround maintenance meant thousands of gasket changes
• shipyards and the Navy, where high-pressure steam systems ran on asbestos seals

If you or your family member worked around industrial piping in any of these settings, the exposure history is usually easy to reconstruct.

The manufacturers and the trusts

Gasket and packing recovery is broader than almost any other asbestos product category, because it runs against three kinds of defendant at once. The major bankrupt makers now pay through trusts that require no lawsuit. The major packing makers who never went bankrupt still defend cases in court, and those tort recoveries often exceed what the trusts pay per claim. And because so much of this work happened during refinery and plant turnarounds under the site owner's control, the facility owners can be reached as premises defendants. A single career often supports all three at once, and one pathway doesn't reduce another.

A brief note on one name you may hear: whether a claim reaches a company like Anchor Packing depends on a successor-specific analysis, and that legal detail is something we work through for your file rather than something you need to sort out. If the idea of a lawsuit is uncomfortable, you're in good company; Clarence Borel, the refinery insulator whose 1973 case built the modern asbestos-litigation system, didn't want to sue either, and we can pursue trust claims alone if that's your preference.

Sources of compensation

A gasket and packing case usually draws from several sources at once, and they run in parallel:

• Asbestos bankruptcy trusts. The makers who went bankrupt set aside money to pay the people they harmed. These are paper claims, with no lawsuit and no courtroom, and one career often supports filings against several trusts. How asbestos trust claims work.
• Lawsuits against solvent makers. John Crane, Chesterton, and Crane Co. are still in business and can be sued directly. How product liability lawsuits work.
• Premises liability against site owners. The refineries, plants, and utilities that controlled the worksite can be held responsible for the conditions they allowed. How premises liability claims work.
• Federal and disability benefits. Navy service can support VA disability benefits, and civilian shipyard work can support Longshore (Longshore and Harbor Workers' Compensation Act) benefits, both paid in addition to the rest. How asbestos disability and benefit claims work.

The makers raise the same handful of arguments in most gasket cases, and none is new to us. All of this applies only to the lawsuit side. Trust claims are a paper process: no opposing lawyer raises defenses, no one is deposed, and no one goes to court.