Name: Jo
Country: UK
Message: Dear Paula

The information that you have on your website regarding chemicals that can be used to remove dye and neutralize the damaging effects of chlorine bleach is very interesting and informative and I wondered if you could help me? 

As a textile designer I regularly use thiox and formasol to discharge cloth but I would like to find a safer alternative, although I do always wear gloves and a proper mask.

I wondered if you had ever come across the product Milton Sterilising Fluid? It is an aqueous solution of 2% sodium hypochlorite and 16.5% sodium chloride used to sterilise baby feed equipment. According to their website www.milton-tm.com it is 'harmless and leaves no unpleasant taste or odour. When in contact with protein, Milton breaks down to WATER and minute traces of salt. It is therefore totally safe and can be applied directly to the skin - even swallowed - without harm.' 

I have done some preliminary tested on fabric and undiluted it bleaches commercially dyed fabric almost instantly and even when diluted still bleaches the fabric quickly. 

I have contacted Milton and asked them to send me the material data safety sheet for the product which they have done and I am happy to send to you if you are interested but I wondered if you knew if it was ok to use and if so, if it is ok to neutralize with Anti-Chlor?

I look forward to hearing from you.


I don't see any reason why you should not use Milton Sterilising Fluid as a dye discharge agent, but I don't believe that it will necessarily be any safer for you to use than thiox or formosul.

Sodium hypochlorite is a common and somewhat dangerous household chemical. It is exactly the same thing that is in household bleach. Commonly, household bleach contains 5.25% or 6% sodium hypochlorite by weight. Milton Sterilising Fluid does not appear to be anything special; the addition of the sodium chloride is irrelevant. Your Milton Sterilising Fluid is essentially the same thing as a 1:3 dilution of common household bleach. It is not appreciably safer than household bleach, and I suspect that it is not any safer than the chemicals you have already been using. It is a reasonable choice for dye discharge, but it does not represent a major safety improvement as compared to the other chemicals.

Whether you use thiox, formosul, or hypochlorite, you must be careful to protect yourself from damaging fumes. An electric fan set in a nearby wide-open window helps to provide ventilation, but you should also use a respirator. The same type of respirator is recommended for all three of these, a cartridge respirator fitted with an acid gas/ammonia/formaldehyde cartridge.

If you use Milton Sterilising Fluid as a dye discharge agent, you should neutralize it afterwards just as you would other brands of hypochlorite bleach. Anti-chlor, Bleach Stop, and 3% hydrogen peroxide are all effective for this purpose; hydrogen peroxide is the safest choice for asthmatics who are senstitive to sulfites. Be sure to rinse out the bleach with water first, before neutralizing your fabric. In contrast, thiox and formosul are neutralized by the oxygen in the air, so there is no need for a separate neutralizing step when you use them as discharge agents.

In spite of the claims you saw, it would be highly unwise to swallow undiluted Milton Sterilising Fluid. Perhaps they don't mean that it is safe to swallow the undiluted fluid, but instead the diluted solution, which contains 30 ml per 5 liters of water; this is over a hundred-fold dilution, resulting in a 0.012% solution, which would be safe, though not very pleasant to taste. For more safety information, a good source would be the JT Baker MSDS for sodium hypochlorite.

The only way in which sodium hypochlorite may be less hazardous than the thiox (thiourea dioxide) and formosul (sodium formaldehyde sulfoxylate) would be if you are sensitive to the sulfur compounds, which for some people can trigger an asthma attack if they are exposed to even minute quantities. The problem with the sulfur-containing discharge agents is that they produce sulfur dioxide, which is toxic and dangerous, if used incorrectly and without safety equipment, but sodium hypochlorite is also toxic and dangerous, if used incorrectly and without safety equipment. Each of these products should be safe for you to use for dye discharge if you are careful to take the appropriate precautions.

For more information, see my page on "What chemicals can be used to remove dye?".

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