Cleaning a sink - two questions

did you not look on the bottle? Have you not googled?

yes, no, yes, no. Bleach only damages ss if left in contact a long time eg over night.

NT

Had you previously put something else (e.g. bleach) down the sink, in an attempt to unblock it?

I have now. The bottle only says it contains sodium hydroxide, not the composition of any fumes. Google says NaOH fumes are dangerous. I assume however that the fumes are produced by a reaction with something else so I am unfortunately none the wiser.

Thanks. I'll give that a go then.

NaOH in water, the fumes are vaporising of the solution due to heat (exothermic reaction, dissociation of the Na and OH)

Owain

It is concentrated Caustic Soda (Sodium Hydroxide) and has a strong exothermic reaction when added to water. In this case the water in the sink trap boiled when the Sodium Hydroxide was added producing the caustic steam/spray. It wasn't reacting to anything other than water. Caustic Soda is one of the few chemicals in domestic use where all the little warning symbols really mean it. A drop in the eye can cause irreversible damage. It will also mark stainless steel. It is very corrosive.

If you mean pour strong bleach in then add water this may well damage the sink surface. Dilute bleach is fine as long as it isn't left to stand in the sink. See

for some objective tests. Note also that "Stainless Steel" has many variants and finishes - what doesn't mark one may well affect another.

Work for what? Dilute bleach is an effective anti microbial. It isn't a particularly good cleaner..

Quite possibly, some plugs have a plated (metallic) finish and bleach may affect these. The more concentrated the bleach the greater the potential for damage. Caustic Soda will also cause damage. Most concentrated bleach bottles warn against undiluted use on metals.

I'd hate to be using strong acids & alkalis and not know what I was handling.

Will the bleach come into contact with the NaOH?

NT

No, I'll leave the bleach for another day after a few gallons of washing up water have made the passage. .

Alkaline steam then? Next time I'll open the window first !!!

Water or any acid

hot steam with possibly a little hydronium, sidioum hydroxide and other interesting things depoending on what was blocking the sink

Yes its fine

If it is blocked or something? A sink plunger costs about a quid or less.

Was the cleaner a solid or liquid? If solid, the action of dissolving in water is massively exothermic so you might have had a steamy mist of the solution.

It's not that much to worry about, unless you get an eye full.

The biggest danger is explosive boiling and getting a facefull with could lead to caustic burns and blindness. But the mist isn't particularly nasty in itself assuming you don't sit there inhaling it deliberately.

On the scale of nastiness, ammonia is much more horrid stuff.

Nothing should happen - both are alkalis.

Bleach and strong acids like spirits of salts (HCl) is potentially deadly though - I did that in the garden as a kid (with some expectation of what would happen) and it belched clouds of green chlorine. Janitors have killed themselves doing that in confined spaces.

That's why they tell you not to mix different kinds of lavatory cleaner. Some contain sodium hypochlorite and others - the limescale removing ones - hydrochloric acid.

Thanks for that. I was genuinely getting a bit concerned when I googled sodium hydroxide. You have reassured me.

Incidentally, I believe people who wear glasses (as I do) have a significantly lower risk of eye injury.

Thanks. That is indeed what seems to have happened. The sink was moved years ago (not by me) and there is now a very long run to the start of the drain.

bleach contains NaOH IIRC. I surely asked the wrong question for some reason.

NT

Bleach contains NaClO :)