Just been watching the cars getting de-contaminated in France with caustic soda...

Whats that stuff going to do to your car, its wheels and tyres, CV boots etc? As far as I know caustic soda will eat through almost anything

Sounds a bit scary to me Where's our resident chemistry expert when he's needed

Sodium Hydroxide you mean It shouldn't damage steel, but Aluminium is a different matter...........................

I would guess it's diluted right down, but it can still do damage I would think.... :chin:

nasty stuff got a fair big scar on my foot with caustic looks like a gun shot scar horrid stuff

http://www.coogee.com.au/msds/caustic%20soda%2050%25.pdf

That's for 50% caustic solution, which is pretty strong. Doubtless they will be using something like 0.5% solution.

Caustic leaches the fats out of your skin and burns straight in, not just on the surface like some chemicals. It feels soapy to touch, but it's actually your skin fats you can feel.

Caustic doesn't attack rubber or mild steel to any great extent, the salt on UK roads is a bigger hazard.

Effects of NaOH (Caustic Soda/Lye) on cars:

Caustic soda is nasty stuff, handling within labs is usually with gloves, goggles and lab coat along with serious care and attention. A water bucket, eye wash and emergency shower should always be available. A mop should be close by along with supervision. LD50 (mouse) is about 50mg /kg. Any reaction with eyes will require 15 mins of water flush and an immediate hospital visit. Any skin touching will require instant and constant flushing.

There are a lot, lot worse substances however, caustic soda of anything like 1 M or above is pretty harmful. It eats at the oils in your skin and turns them into soap (basically) which is why it is slippery. Typically, the reason why NaOH is seen as a fairly nasty substance is because it is often used at high concs.

For the above reasons, there is no chance whatsoever that the concentrations used will be more than very, very low concentrations.

NaOH is fine on iron (which of course most cars are made out of) and plastics (the majority at least). It doesn’t however like aluminium as pointed out.

Since a fair bit of some modern cars is made out of aluminium, I again suggest that the concentrations used must be very low.

Hope that helps, if/when more information is made available I can re-evaluate.

Incidentally, I faced a small scale spillage whilst using caustic soda due to a valve sticking. It took 30 seconds to get enough water and towels to contain the spillage which was 0.5 x 0.5 m in size. When cleaning it, the red paint on the concrete floor was lifted. I am not sure of the type of paint used but this would worry me. The concentration used at that point of the experiment was approx. 0.2 M – which is still reasonably high. This wasn’t covered in the COSHH analysis but quick research shows that caustic is a good oil based paint remover.

Again, it all depends on the concentration in my opinion and I assume it would not be used if a serious worry exists about the paint effects. Oh and it might be reasonable that a quick spray with caustic of low conc is followed by a long spray of fresh water.

that from google or paul?

Who's reminded of the scene with the lye and the hand-burning in Fight Club?
H

If we get a plague of bird flu, we should just not take them out anymore and say 'we should see other people'