95% Sulphuric Acid On Sale In Diy Stores

[NiceCupOfTea]

I was horrified to see this on sale at my local little DIY store as a drain unbloker. This is seriously scary stuff, should it not be restricted?

[Slapshot]

We use my wifes tea as a drain unblocker..... ;0)

I would have thought some restrictions were necessary especially at that molar strength... interesting

[douglas9401]

It will be, but along with pickaxe handles, Stanley knives, nail guns and gas canisters it's designed for a purpose.

[NiceCupOfTea]

That makes me laugh. My old boss would not believe me how scary HCl was, this is worse.

[sandyRoe]

If anybody has plastic pipes under the sink I hope they don't use this to try and unblock them.

[NiceCupOfTea]

Why? It reacts with metals?

[douglas9401]

I've used it in plastic pipes, Sandy. It stank the whole house out while it was working but it did the job, no problem.

[NiceCupOfTea]

Thank you, that's what I should have clarified... it doesn't affect a lot of plastics.

[sandyRoe]

I didn't know that. I imagined it would eat through anything.

[Calibax]

I'd be more worried about the exothermic reaction with water!

[NiceCupOfTea]

it's totally placid when in a plastic bottle. If it gets to metal, get out of the way in most instances as it goes mad.

[sandyRoe]

Does anyone remember glass carboys in wicker baskets? Would it have been acid in them?

[NiceCupOfTea]

acid drops hitting water are fine, they're tiny and heat up only a small amount. water hitting pure acid is not good as it heats up like mad and splashes back at you

[Old_Geezer]

What was the 5% ?

[sandyRoe]

Hope it wasn't water

[stuey]

I cannot believe that 95% sulfuric acid is being sold in a general store. That concentration of acid is of a syrupy consistency. I used to work in a lab, and to handle that strength of acid you wore protective clothing and head gear. And always remember to dilute strong acid you add acid to the water and not the reverse.

[stuey]

Plus this concentrated acid came in glass carboys, and all the drain pipes in the lab were glass. You don't use that stuff on ordinary plumbing.

[sandyRoe]

I think I remember seeing carboys corked with cork. Was that the way they were stopped?

[jomifl]

Caustic soda is usually used for unblocking drains as it deals with congealed fat better than acid and doesnt dissolve the jointing in ceramic drain pipes. Sulphuric acid also generates hydrogen (very explosive) on contact with metals and H2S (more poisonous than cyanide)on contact with sulphides so uness you know that your drains are all plastic you should use caustic soda.

[stuey]

If I remember correctly, Sandy, the stoppers were also glass.

[theprof]

Sulphuric acid of this concentration can perfectly legally be sold in hardware stores for the purpose of unblocking drains etc. The package has to disclose that this is the sole purpose for the use of the product. Obviously, instructions regarding the action to be taken regarding spillages, accidental consumption etc have also to be made clear.
With regard to the use of the product in domestic plastic plumbing, there might well be concerns. Sulphuric acid of this concentration can attack ABS, PE-X, PVCu, MDPE and similar polymers all of which are used in plumbing. I’d expect the packaging to mention this issue although I appreciate that most people don’t know what type of plastics are contained in their plumbing network. If in doubt, I would not use this product. I can think of about 50 plastics or groups of plastic offhand that 95% sulphuric acid would attack, although it’s been quite a few years since I lectured in chemistry at uni.
Safety requirements in labs do demand the wearing of protective clothing and headgear, but I’m afraid that laboratory requirements under COSHH regulations and the myriad of others I and my colleagues have to abide by will always be more stringent than those demanded in domestic situations.
The viscosity of the acid is not really relevant. There are many grades of Sulphuric acid available ranging from very impure, technical grades to extremely pure high-grades used in very demanding laboratory work. A typical acid of this concentration may or may not have a viscous consistency. I used a 100ml 98% H2SO4 sample only a week ago that had a viscosity only slightly higher than water. Besides, you have to remember that many drain cleaners, be they acid or alkali are thickened deliberately using carboxymethylcellulose and the like, because the public consider thicker solutions to be “stronger” or “better” than thinner solutions. The so-called “thick” bleaches are a case in point.