[WhatTFDidIJustMake]

I was cleaning my bathtub with BLEACH and when i was finished, didn't rinse it out right away. i then noticed that the drain was clogged so poured a strong industrial drain cleaner down the drain. the drain cap then flew off and spewed a white foam that smelled like something other than bleach. the chemical i put down the drain contained almost 100% SODIUM BISULFATE. almost as soon as the reaction happened my brain began to tingle and i knew some kind of gas was causing the feeling as soon as i stood up to try and run out of the bathroom i fell to the ground and started to black out. lucky i made it out crawling on the ground and managed to fall down the stairs and sat out on the lawn(in tears). i knew it had to of been some kind of nerve gas considering how i felt. i also know it wasn't chlorine gas as that would have caused my throat and eyes to burn(which didn't happen). but seriously WhatTFDidIJustMake!?!?

[Borek]

Sodium bisulfate is just an acid, whatever was produced was most likely effect of the reaction with something that was present in the drain water (or deposited in the drain). Hard to tell what it could be, but I would definitely not classify it as a 'nerve gas' with such a limited information.

The most common products in similar situations are chloramines, but you have not used ammonia, besides, chloramines smell similarly to chlorine.

[WhatTFDidIJustMake]

thank you for responding! just one thing. I've never put anything down the drain but that bleach and i didn't run water down it to rinse it out. I'm positive it was a reaction between the sodium bisulfate and bleach because it never foamed up when i used it other times. I'm just pretty scared about possible permanent damage to brain cells as my head began to feel like my foot does when it falls asleep. and after some research I've found out mixing any acid with bleach is extremely dangerous. it had a kind of funky bleach smell but again didn't cause any facial or respiratory pain. i feel like its a reaction that should really be looked into because when i look it up i can't find anything on it. 

[Borek]

Reaction between bisulfate and bleach (hypochlorite) is trivial - and produces just chlorine.

[Babcock_Hall]

Borek,

Would the sodium bisulfate protonate the hypochlorite ion from bleach?

[Borek]

Yes, while HSO₄^- is considered to be a weak acid, it has pKa of 2. When talking about solutions of sulfuric acid we can neglect it as the first dissociation makes it negligible, but in the solutions of bisulfates it acts just as an acid.

[pgk]

I’s not sodium bisulfate, but rather sodium bisulfite solutions or the solid sodium metabisulfite that are used for cleaning and sanitation. Anyway, the reaction between bisulfite and hypochlorite produces bisulfate, etc. and  then chlorine, as above described. Besides, concentrated bisulfite solutions or solid metabisulfite salts in contact with tap water, release SO2 which is a pungent and unpleasant smelling gas (odorous white foam?). 

[Kemistry Kaiser]

Yeah that makes perfect sense, but I thought SO₂ was a respiratory irritant and he said he didn't feel any burning. Is it possible to inhale trace vapors of it without showing physical irritation?

[pgk]

Yes. SO2 is not so strong respiratory irritant compared to other irritants e.g. SO3 or chlorine, in terms of acute inhalation.
However, a serious impact on the respiratory tract and lungs, as well as eyes irritation occur under prolonged contact with.
If you prepare a sodium bisulfite solution by dissolving sodium metabisulfite in tap water and you smell it, it has unpleasant odor but you will not immediately start to cough.
Besides, the preparation of aqueous NaHSO3 from Na2S2O5 is endothermic, therefore sedimentation occurs under heating e.g. by simultaneous oxidation to NaHSO4, which is exothermic (white foam?)

[Borek]

I’s not sodium bisulfate, but rather sodium bisulfite solutions or the solid sodium metabisulfite that are used for cleaning and sanitation

Wikipedia points to this page:

http://www.rbnainfo.com/productpro/ProductSearch.do?brandId=30&productLineId=518&searchType=PL&template=1

[pgk]

I am known to be occasionally wrong, too. Besides, I do not have the label of the used product, in front of me.
But the said “SANI-FLUSH® Powder” does not seem to be 100% SODIUM BISULFATE.  And the cited function of the described ingredient (or at least, some of them) does not seem to be correct.
However, SODIUM METABISULFITE could roughly be considered as 100% SODIUM BISULFITE.

[Babcock_Hall]

Toilet bowl cleaner seems to have bisulfate:  http://aces.nmsu.edu/pubs/_g/G304/welcome.html

This site has a list of chemicals and a table of other chemicals that are incompatible with it.  Under sodium bisulfate, it lists "calcium hypochlorite Chlorine Bleach" as being incompatible.

[pgk]

Ok, agreed. Besides, the reaction between bisulfite and hypochlorite produces bisulfate, etc. and then chlorine, as above described. Anyway and as a general rule, hypochlorite and other bleaching agents must not be mixed with other cleaning formulation because toxic chlorine gas and strong exothermic reactions can be produced.