[gasbag]

I have a query regarding Sodium Thiosulfate.

I'm a regular swimmer, were I add Sodium Thiosulfate crystals to my shampoo and conditioner to neutralise the chlorine in my hair.  What I want to know is what concentration of Sodium Thiosulfate, in grams per Litre, should I add to shampoo/conditioner/bodywash/moisturiser?  At the moment I have absolutely no idea how much I should be adding.

[Arkcon]

I wouldn't add any crystalline reagent to something I was going to rub on my body, and into my hair and let it rinse over my face, eyes, and mouth.  Its very difficult to figure out how much residual chlorine remains in your hair and then compute the amount of needed thiosulfate.  Maybe there are commercial anti-chorination shampoos, but they've conducted the research into what quantities of what chemicals are needed for a balanced shampoo that isn't hazardous.

[Vargouille]

Sodium thiosulfate isn't very hazardous. The median lethal dose for rats is >5000mg/kg, and the oral lowest published toxic dose for humans is about 300mg/kg over 7 days. Sure, with chronic use there could be irritation or sensitivity, but the same is true of most things.

But rubbing the crystals themselves into your hair isn't the best idea, I'll admit. Just play around with the ratio for how often you swim. I would start out with an eighth of a teaspoon of sodium thiosulfate in a gallon of warm water, and adjust as needed. After all, there isn't much chlorine in pools, and even less will stay in your hair.

The only warning with using sodium thiosulfate is not to heat it above 100C, as it decomposes, giving off SO2.

[gasbag]

Thanks for the replies all.

In regards to toxicity issues, Sodium Thiosulfate is actually the active ingredient in most dechlorinating swimmers' shampoos; if the stuff is toxic/hazardous, it's been on the market in these products for years.  I have been adding "just a few" crystals to my own regular shampoo (much more cost effective), but I just have no idea how much I should be using - that's the issue.  Which is why I'm asking here.

If anyone can provide any specific concentration advice, I'd greatly appreciate appreciate it.  Again, thanks.

[Arkcon]

Actually, no one on this forum can.  It is specifically against the Forum Rules{click} which we all agreed to when we joined this forum.  We don't give specific help on self medication, for liability reasons.