I need to know the TLV of Iodine but don't have a current list. Can anyone help or say if there is a website ? Merv

WoW - what's a TLV - I guess it's a totally low-risk volume :) I Google'd it and got - (Iodine) ACGIH TLV 0.1 ppm, lots of MSDS I only picked one at random. This would match the UK WEL - EH40 says: Iodine 7553-56-2 - - 0.1 1.1 R20/21, 5 I always use http://esis.jrc.ec.europa.eu/ but it doesn't appear to give info on TLVs or WELs for iodine and I can't link you to the iodine page.... happy days.

Some of us remember from early childhood that iodine or perhaps a yellow paste made from the stuff was routinely available and used as a disinfectant/antiseptic (apologies for any incorrect terminology) for skin grazes, cuts and for stitched skin after surgery. It had quite a sting and probably stained clothing as well, but was apparently very effective. Though this nugget of information doesn't specifically answer the query posed, it may still have some peripheral relevance. Furthermore, though my memory might be playing tricks, I recall seeing seeing an article recently which described how iodine is now making a comeback in medicine, perhaps including as protection against MRSA. As I've no time to do an internet search now (about to go out to do an investigation), please can better informed forum users confirm or deny this aspect?

Bring back Isopropyl Alcohol 70%bv! That's what I say!

Iodine: ORAL (LD50): Acute: 14000 mg/kg [Rat]. 22000 mg/kg [Mouse]. Source Sciencelab.com The data provided is for the element, not a compound.

You're in a real grump tonight Ian. That's three grumpy posts one after another. Perhaps you should find another outlet for your frustations. Seriously.

It's Friday so...I asked the waiter for iodine and I dined alone...anyone remember that line? Your red scarf matches your eyes, please close the cover before striking... From memory, I didn't even ask another forum member to Yahoo! it for me (blatant plug there for another search engine).

teh_boy, I'm here.

Ian B - Thanks for your information about iodine and correcting my misperception about its use as a disinfectant. Presumably OTC means 'over the counter'. Also though all the chemical elements classed as halogens (4 from my recollection of 'O' level chemistry many years ago) apparently have antiseptic properties, is it the case that iodine is the least vicious to users and/or most effective as an antiseptic in contact with people or is it the case that its concentrations for such use are carefully controlled? In addition, irrespective of whether or not I'm among those accused of laziness regarding internet searching, my response is that the internet contains some useful information - and also a lot of nonsense and misinformation. Therefore, sometimes such searches can be quite time-consuming because they involve looking at a number of websites in order to sensibly compare and evaluate their information. The same surely applies to information and opinions posted on this discussion forum! This is why I've suggested from time to time that IOSH should reinstate from the forum's former format the standard warning to users about not relying on its contents when making decisions, etc.

I finally thought to ask Jeeves (ask.com) and they/he gave a list of about 10 sources and values for LD50, all different, ranging from 500 to that 14000 mg/kg on a Merck website. Most seem to be in the 5-7000 range. Still haven't found an authoritative source. Could be a purple or burnt sienna Xmas for someone. Thanks again everyone Merv

quote=Graham Bullough]Presumably OTC means 'over the counter'.

Yay, we did it! That was hardcore.... My link contains more info than you can shake a stick at Now where's the wine?

For tanked recirculating recreational waters the chlorine concentration is in the range 1-4 mg/l depending on pH, the use of stabilisers and predicted loading. A dab of iodine ointment on a superficial wound or iodine skin scrub is formulated to deliver 1% and 10% iodine respectively. Greater reactivity, lesser concentration, with some allowance for volatility and patterns of exposure (eyes) etc