Did South Africa save us in World War II? Amosite Asbestos. It’s History and Uses.

Amosite Asbestos fibers are nasty stuff which you should avoid breathing at all costs. Amosite Asbestos (also known as asbestiform grunerite) is generally considered the second most dangerous form of asbestos after crocidolite. Amosite is only known to exist in the Transvaal region of South Africa but was widely shipped to and used in the United States. It was first spun into a commercial product in 1909 with full scale production beginning in 1916 by the Cape Asbestos Company. The fiber was called “amosite” after the name of the mine (“Amosa-Mine”). It is known as “Brown Asbestos” because of its coloring. Interestingly, it is sometimes found in South Africa mines along with crocidolite.

Amosite was extensively used in thermal insulation and fire-proofing material manufactured by Cape Asbestos Company in South Africa including international trade names such as Caposite, Asbestolux, Isolamiante, and Unibestos.

It was also used in Molten Marinite manufactured by Johns-Manville in the United States and, at times Kaylo insulation manufactured by Owens Corning.

In summary, the use was extensive for these types of products. By the way, the above photos are taken from the old Owens Corning Picture Books showing their competitors’ products. Let me know if you would like to see additional product labels should you they be helpful to you.

All asbestos during World War II was in such demand that the United States Government created stockpiles for each. As to the Amosite stockpile, the government felt it sufficiently important to keep a large quantity on hand. The Minerals Yearbook from 1943 stated as follows:

“Amosite, mined only in Africa, is a critical variety that has important military uses, including woven insulation for ship work, 85-percent magnesia and other high-temperature molded insulations, fire-proof marine insulating board, and sprayed-asbestos insulation.  It is difficult to increase the production of amosite, and future requirements are not assured for as long a period as is desirable.”

Let’s take a step back. As a shortage of Amosite Asbestos was critical and the only availability was from South Africa, what might have been the outcome of the war if South Africa was on the side of the Axis? This is especially interesting as Germany was very short of asbestos during World War II and spent a lot of resources trying to develop asbestos substitutes.

It is a horror just to think about it. If you want to know what British Intelligence thought about this, then you should read the post-war publications by the British Intelligence Objectives Sub-Committee entitled German Asbestos Industry (Report 404), The Asbestos Textile Industry in Germany (Report 460), Asbestos Consuming Industries in Germany (Report 992), and Technical and Scientific Developments Related to the Asbestos Industry in Germany (Report Number 1070). I am willing to lend out my only copies of these publications to anyone who really digs military history. Otherwise, you make your own decision about how much we owe to South Africa.

I know, I know. Some of you are going to say that South Africa was a British Colony during World War II and so they had no choice. However, this was not a given as stated at South Africa Online:

“In September 1939, World War II broke out. In South Africa, people were divided as to whether or not they should join the war, and if so, on whose side they should fight. Although South Africa was still a British territory many Afrikaners felt closer to the Germans. Many of them were of German descent and identified with Germany’s fight against Britain. The issue caused a split in South African politics.“

So close. So very close.

After the war, the United States government kept using and refilling the inventory for amosite as necessary. As stated in the Minerals Resources for Year 1964:

“Consumption of crocidolite and amosite represented by imports continued to increase.  Imports of crocidolite and amosite in 1964 were 25,000 and 24,000 tons respectively, compared with 11,000 and 22,000 tons in 1963.”

The uses continued to increase as the government used 30,844 tons of amosite in the year 1990. The government finally liquidated their remaining stock on hand in the year 2000.

One of its highest volume uses for amosite was on Navy ships for pipe insulation. Many a retired Navy sailor has testified to these pipes throughout the ships, including right above them where they bunked and the pipes shaking when the big Destroyer guns were firing. Of course, other asbestos containing components including crocidolite and chrysotile fibers were used on Navy ships such as gaskets, packing, and cement. I have seen one estimate that 300 asbestos containing components were either used in the Navy ship construction or on the ship itself.

The appearance of Amosite Fibers is very different than Chrysotile Fibers. Amosite fibers are generally shorter and wider. Further, they usually have smooth straight sides. There are lots of other differences as discussed in scientific terms in the book Asbestos Properties Applications and Hazards, Volume 2 published in 1983. Also, the 1981 publication entitled Reviews in Mineralogy, Amphiboles and Other Hydrous Pyriboles-Mineralogy, Volume 9A, by the Mineralogical Society of America has an excellent discussion on the fiber types and the broader issues concerning amosite in Chapters 5 and 6. For people who want to get in the weeds on the science, those are excellent sources. Let me know if you would like to borrow either of the publications.

I hope that the above is useful. Let me know if you have any questions, would like to borrow a book, or would like a copy of my sources of information. I can be reached at TheAsbestosBlog@gmail.com.