Asbestos(?) water tank

[harryagain]

"Artic"

[The Natural Philosopher]

Utter rubbish. teh hazards of asbestos came after lifetime exposure to dust in mines and factories where it was prevalent.

breaking one up when wetted to kill dust just once wont be in any way hazardous.

we used to mill cut and saw asbestos with no particular worries for years and years, and no one died of it or even got ill.

Personally Id rather hack at asbestos than rout MDF. That truly is dangerous dust.

>

[Grimly Curmudgeon]

Ah; one of the old women speaks.

[Dave Liquorice]

would

Sometimes people go down with mesothelioma 30 years after a very brief and relatively low level of exposure. Like wise someone can spend their entire working life with the stuff and not have any problems. Worse are the cases of the wives of asbestos workers who go down with it from the dust off their husbands clothes...

I'm on an "asbestos regsister" because I used to work in a building made with asbestos panels. Very strict "no drilling" rules, regular air monitoring and grey dust that would form fairly quickly... The put the entire building into a negative pressure bag when they demolished it and everything that came out was double bagged.

There certainly is a bit of over reaction when asbestos is mentioned and the white cement stuff is fairly benign. If I was to cut or break it up I'd damp it down regulary and wear a proper half mask, not a silly little pressed paper thing.

[Onetap]

Agree. You just need a car it will fit in or a roof rack and check the skip at the dump will take it.

[Onetap]

They don't though, until 30 or 40 years later.

A pipe fitter I used to know had kept in contact with many of his mates from technical college. He was on the verge of retiring & said 6 or 7 (I think) of the class were known to have died from asbestos related illnesses. Lifetime exposure, maybe, but the problem is that no-one can set a safe level of exposure. 1 fibre could start a cancer.

[meow2222]

Just one trip to the shops in the car could kill you - its just a vanishingly small risk. Ditto with breaking one white asbestos cement tank. Do it repeatedly and the odds mount up.

NT

[Peter Crosland]

Which just shows the degree of your general arrogance, and ignorance on the subject. Quite short exposures to asbestos can result in mesothelioma many years later. There simply is no safe level of exposure to it. Even though the risk in the OP's case is small that is no reason to be complacent about it. The OP can easily dispose of it safely without much trouble so there is no reason for him not to do so.

[Jim K]

Hmmm bit of a climb down from your first Corporal Jones outburst then?

Jim K

[Huge]

Glad to see you're still fully justifying your killfile entry.

[Peter Parry]

You should start panicking now then as everyone breathes several fibres a day. As for London underground users - well they are doomed. There is a well established (and quite conventional) dose/exposure/risk relationship. The longer and larger your exposure the greater the risk. The panic over asbestos at very low levels is not the real risk but that in law there is no lower absolutely safe limit. After a case some years ago anyone with asbestos related disease can sue any employer they worked for at any time if they can show even minimal exposure to asbestos containing materials. Essentially such claims cannot be defended and there is an industry of bloated solicitors (plus their boats and horses) supported by asbestos claims.

Asbestos is everywhere and there is no one who has no exposure to it. Control measures do not attempt to produce zero exposure which is impossible. Asbestos cement is not the same as asbestos and the risk of disposing of it is minimal. Other materials with low levels of asbestos such as asbestos cement include old Vinyl floor tiles and any number of ceiling boards. Most of these are hacked out and thrown away without anyone even realising they contain asbestos.

[Chris Hogg]

I'm not sure you have a very good understanding of asbestos, either. The term 'asbestos' is generic and is applied to at least two classes of minerals with very different properties, but both of which are capable of occurring in fibrous forms.

Blue (and more rarely, brown) asbestos is crocidolite, a fibrous variety of the mineral riebeckite, Na2.(Fe2+)3.(Fe3+)2.Si8.O22.(OH)2. It was frequently used in thermal insulation, e.g. pipe lagging, especially on ships where fire-proof insulation is to be preferred (this accounts for the hot-spots of mesothelioma that occur in the vicinity of naval dockyards). When inhaled, these fibres do not get trapped in the nasal passages and upper airways, but lodge in the inner recesses of the lungs. Because of their length, and because they do not dissolve in the very mild acids present in the lining of the lungs, they persist, irritating the tissues and eventually causing a tumor and the form of cancer specific to this form of asbestos, mesothelioma. Blue asbestos is very hazardous!

White asbestos is a fibrous variety of the mineral chrysotile, itself a form of serpentine (thin veins of chrysotile can be found in the cliffs on the Lizard peninsula in Cornwall). It has formula Mg3.Si2.O5.(OH)4, very different to that of crocidolite above. The fibrous crystals of chrysotile tend to be shorter and chunkier than those of crocidolite, and as such it tends to be used in different applications, such as fibre reinforced cement. Because of its different fibre shape it is more readily trapped in the nasal passages and upper respiratory tract and fairly quickly expelled from the body (by sneezing, coughing, nose-blowing, phlegm-gobbing etc.). Being embedded in cement (at around the 10-15% level IIRC), makes the occurrence of free fibres even less likely. Those fibres that do get through to the inner recesses of the lungs are slowly dissolved by the weak acids present there, eventually disappearing after a year or so, unlike the fibres of crocidolite which persist for many years.

Hence 'white' asbestos is generally regarded as much less harmful than the extremely hazardous 'blue' asbestos. However, for some years after the end of WW2, both white and blue asbestos were used in cement products, although use of blue asbestos in this application was eventually phased out, IIRC in the early 1960's. The problem is that it's not immediately obvious which variety of asbestos is present in any asbestos cement product, especially if it's old, say over 50 years. Hence the regulatory authorities decided to play safe and required that all asbestos products should be treated with the same degree of caution, which for white asbestos in cement is a bit over-cautious.

All this is from memory. I used to have references to key points, but have long since deleted them, and I'm not inclined to go searching for them again.

To the OP: My mother has a similar asbestos-cement water tank in her roof, in a property that was built in about 1960, that I will have to deal with eventually. The advice given here is sensible. Don't be cavalier with it, but don't be terrified by it. Avoid making dust. If you can dispose of it without breaking it up, do so. Failing that, keep it wet, wrap it well (old bed-sheets would seem ideal) and smash it into large bits with a hammer, before double-wrapping it in heavy duty polythene (e.g. damp-proof membrane) and disposing of it through the appropriate channels, as described by others in this thread.

This is one application that would _not_ be suitable for an angle grinder!

[Adam Funk]

I'm curious: why did they make water tanks with asbestos? They're not normally considered a fire hazard.

[The Natural Philosopher]

It may not BE asbestos anyway. A lot of stuff is/was made out of cement with a fibrous filler in it to add tensile strength - early version of fibreglass really.

Asbestos was one suitable fibre. There are others.

[Jim K]

Er used as reinforcing for thin cement moulded products, troughings, roofing sheets, water tanks etc

Jim K

[fred]

In article , Chris Hogg writes

An excellent post, thanks for sharing your knowledge.

[The Other Mike]

So that if the house caught fire, the water tank would not put the fire out and you coudl get a full rebuild rather than a repair?

I'd guess light, cheap, non rusting

[Peter Parry]

I don't think anyone ever produced an asbestos tank. Tanks were made of asbestos cement which contains about 90% cement and 10% white asbestos fibre as a cheap, lightweight non corroding fibre reinforcement. The mixture was easy to pressure mould so used for roofing sheets, formed items such as water tanks, drainage pipes etc.

[The Natural Philosopher]

..and has never been associated with any especial dangers.

[Adam Funk]

(I didn't mean "with" = "entirely from".)

Fair point. I was aware of roofing, shed walls, & so on, but had always assumed fire-resistance was part of the point of using asbestos as the fibre.