I'm afraid that I must disagree. You are correct that vinegar will not safely neutralize hypochlorite (the active ingredient in chlorine bleach), and that thiosulfate will, but metabisulfite and peroxide are in completely different categories from vinegar.
The problem with vinegar is that acids react with hypochlorite to form even more caustic and deadly chlorine gas. One should never mix acid with hypochlorite, and vinegar is an acid.
However, thiosulfate is not the only chemical that will safely and completely neutralize hypochlorite bleach. Both sodium metabisulfite (ProChem's Anti-Chlor) and hydrogen peroxide (3% solution) are just as effective and safe as thiosulfate. ProChem does not even sell sodium thiosulfate.
Thiosulfate is an excellent bleach-stopping chemical, but it is slightly less practical for use than Anti-Chlor, because a much larger quantity needs to be used, making it less convenient and more expensive. While one gallon (4 liters) of neutralizing solution requires one ounce (30 grams) of sodium thiosulfate, the same amount of neutralizing solution made with metabisulfite requires less than half a teaspoon, or just 0.9 grams of Anti-Chlor. Dharma's Bleach-Stop costs a very reasonable 25¢ per gallon of neutralizing solution, but ProChem's Anti-Chlor costs less than 1¢ for an equivalent amount.
Hydrogen peroxide works excellently as a bleach neutralizing chemical. Hypochlorite reacts with hydrogen peroxide to form chlorine ion (the same as found in salt water), water, and oxygen gas. Its chief drawback is its cost. A half-liter bottle of 3% hydrogen peroxide solution bottle costs 79¢ at my local drugstore. I once used half a bottle to neutralize a child's shirt, so the cost was about 40¢ for one use; I probably could have used less, but this is not something I want to experiment with. The shirt had been soaked extensively in bleach solution, because its navy blue commercial dye was partially resistant to the bleach action; in contrast, a black tee discharged in the same session was bleached to off-white within seconds. After being neutralized with peroxide, the shirt was worn and washed probably more than a hundred times before it wore out. When the fabric wore out, holes appeared only in parts of the shirt that had never been exposed to the bleach. Thus, experience shows that peroxide is highly effective as a bleach neutralizer on cotton.
Individuals who have asthma and are sensitive to the effects of sulfite-containing preservatives (a chemical essentially identical to Anti-Chlor, problematical for some asthmatics when used in dried fruit or wine) may find that hydrogen peroxide is safer to use than the sulfur-containing bleach neutralizers such as Bleach-Stop or Anti-Chlor. I recommend that people who are sensitive to sulfites always use peroxide as a substitute when neutralizing bleach.
For more information on this topic, see
"How can I neutralize the damaging effects of chlorine bleach?".
Paula
