Asbestos Cement Pipe, Transite, and Marinite

Asbestos cement carried America's water, sided its houses, vented its furnaces, and lined its ships for most of the twentieth century, sold under names like Transite and Marinite as a material so hard and durable it looked like it could never hurt anyone. The hardness was the trap. The fiber sat quietly in the cement until a saw, a grinder, or a drill touched it, and then it came out all at once: cutting dry asbestos-cement pipe with a high-speed disc cutter has been measured at 60 fibers per cubic centimeter in the worker's breathing zone, which in fifteen minutes puts roughly seventeen years' worth of ordinary city background air through a person's lungs¹. The companies that made and used these products ran the same measurements inside their own plants, wrote the numbers down, and told the workers on the saws nothing. 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 cut, drilled, or 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 cement products were

Asbestos cement is exactly what the name says: portland cement reinforced with asbestos fiber, molded under pressure into pipe, flat sheet, corrugated sheet, and shingles. The fiber gave the cement tensile strength the way rebar strengthens concrete, and the result was a material that was cheap, rigid, fireproof, and nearly immune to rot and corrosion. Cities laid it as water and sewer main. Builders nailed it up as siding and roofing. HVAC installers ran it as duct and furnace flue.

Transite was Johns-Manville's brand name for its asbestos-cement line, and like Kleenex or Xerox, the name escaped the brand: workers came to call almost any asbestos-cement sheet or pipe "transite," whoever actually made it. Marinite was a different Johns-Manville product, a calcium-silicate structural board developed for shipboard use, where its light weight and fire resistance made it the standard material for bulkheads (the walls dividing a ship's interior) and joiner work. Marinite matters for a second reason covered below: it ran on amosite, not chrysotile.

Representative products and their asbestos content. These are examples, not a full list:

That Marinite row has an important detail: "Asbestos cement was only chrysotile, the least dangerous type of asbestos" is a defense you'll hear, but Marinite 30 was roughly half amosite, or brown asbestos, a more hazardous amphibole fiber, and much flat Transite carried amosite as well. The cement category was never a chrysotile-only story. And chrysotile is recognized by every major US and European health agency as a human carcinogen capable of causing the same cancers amosite and crocidolite can.

How cement products put asbestos in the air

Sitting intact in a trench or on a wall, asbestos cement doesn't shed much fiber; that's the grain of truth the industry built its "safe product" story on. The problem is that the material almost never went into service without being machined. Pipe came in standard lengths that had to be cut to fit, and every cut end had to be beveled or ground smooth so the coupling would seat. Sheet and shingle had to be sawed to size and drilled for fasteners. All of that was done in the field, usually with a high-speed abrasive disc, right at the worker's waist or chest, and each pass of the blade shattered the cement matrix and threw the fiber it had been holding into the breathing zone as dry, friable (crumbly and easily airborne) dust.

Here is what that machining work measured. Each figure is a phase-contrast (PCM) measurement, which counts only the longer fibers and so it represents the minimum level of exposure, not the maximum.

By the illustrative math on our how we measure asbestos in air page, 15 minutes of cutting dry cement pipe put roughly 17 years of ordinary city air through the lungs. This estimates fibers in the air breathed, not a retained dose.

Look at the wet rows, because they carry this page. Kumagai's team measured moist pipe at 48 f/cc and, remarkably, cutting with a water hose running at 63 f/cc, slightly above the dry figure¹. The water controlled the visible dust, which is exactly what made it dangerous: the cut looked clean while the invisible respirable fiber kept pouring off the blade. "We wetted it down" was the industry's own recommended practice, but in some cases that made it worse.

Play the film from 19:08: Working with Asbestos from 19:08

What the makers and industrial users knew

The strongest part of a cement-products case is often that the hazard was documented inside the companies themselves, decades before the workers on the saws heard a word of it. This isn't an inference from general industry knowledge; it's on paper, in their own files.

Dow Chemical measured it at its own Freeport, Texas plant. A 1973 internal industrial hygiene study of Transite cutting recorded dry circular-saw cutting at 36 f/cc in the worker's breathing zone, with water-saw cutting lower but still elevated⁴. Westinghouse went further down the same road: 1976 internal documentation of wet, fully immersed diamond-saw Transite cutting recorded about 11 f/cc⁵, which is to say that even the most controlled cutting method a major corporation could engineer stayed far above the exposure limit. Alcoa ran its own internal Marinite measurement as well with similar results.

The government record runs alongside the corporate one. The Pennsylvania Department of Health investigated conditions at the General Electric plant in Erie as early as 1951. The U.S. Bureau of Mines' Information Circular 7880 laid out the industrial picture in 1959⁶. And in 1977 the U.S. Navy documented Transite and Marinite cutting exposures at its own shipyard facilities, the same yards where Marinite bulkhead work had been standard for a generation. All of them recorded dangerously high dust levels associated with the fabrication of asbestos cement.

Play the film from 8:00: Perception of Risk from 8:00

Who was exposed

Asbestos cement wasn't tied to one trade or one place; it was wherever water flowed, buildings went up, and ships were fitted out. Rather than retell each worker's story here, we link to the relevant pages for your convenience.

• plumbers and pipefitters, who cut and fit asbestos-cement water and sewer mains
• construction workers, who sawed and nailed cement siding, shingles, and Transite panels
• utility and water district crews, who installed and repaired cement main for decades
• HVAC workers, who ran Transite duct and furnace flue
• shipyard workers, who cut and hung Marinite bulkheads and joiner board

If you or your family member worked around cement pipe, board, or shingle in any of these settings, the exposure history is usually easy to reconstruct.

The manufacturers and the trusts

Most of the companies that dominated asbestos cement have been through bankruptcy, which means most of this category now pays through asbestos trusts: those are paper claims, with no lawsuit and no courtroom. The major exception is CertainTeed, the largest late-era cement pipe maker, whose asbestos liabilities were moved into an entity called DBMP LLC that filed Chapter 11 in January 2020; its trust is not yet finalized, and claims against it are queued for the trust once one is confirmed. And because so much cement pipe work happened on premises controlled by water districts, utilities, and plant owners, those site owners can often be reached as premises defendants in ordinary lawsuits. A single career often supports several pathways at once, and one doesn't reduce another.

Sources of compensation

A cement-products case usually draws from several sources at once, and they run in parallel:

• Asbestos bankruptcy trusts. Manville, Federal-Mogul, NGC, G-I Holdings, and Eagle-Picher all maintain active trusts, and one career of cement work often supports filings against several. These are paper claims, with no lawsuit and no courtroom. How asbestos trust claims work.
• Lawsuits against solvent defendants. Where a responsible company never went bankrupt, or where a site owner controlled the work, the claim proceeds in court. How product liability lawsuits work.
• Premises liability against site owners. The water districts, utilities, and plants where cement pipe was cut and laid can be held responsible for the conditions they allowed. How premises liability claims work.
• Federal and disability benefits. Navy service around Marinite bulkheads 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 defendants in cement-product cases lean on the material itself: hard, gray, and solid-looking, it photographs well for a jury. None of their arguments 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.