Interesting Boron regulation in Australia

[Brakel]

Speaking to NICNAS (National Industrial Chemicals Notification and Assessment Scheme) Australias governing body for safe chemical use in Australia.

I was told products containing boric acid have an S4 scheduling, in Australia S4 goods sold for human use must me sold under the advice of a pharmacist. For therapeutical goods, they must not contain more than 0.035% for topical and eye treatments.

This means that according to the Theropeutical Good Adminstration (tga) that levels above 35ppm of Boronic Acid is considered unsafe for human use and illegal for use in Australia. I have no reference to their findings or research, however this is a concern.

 

[Brakel]

Speaking to NICNAS (National Industrial Chemicals Notification and Assessment Scheme) Australias governing body for safe chemical use in Australia.

I was told products containing boric acid have an S4 scheduling, in Australia S4 goods sold for human use must me sold under the advice of a pharmacist. For therapeutical goods, they must not contain more than 0.035% for topical and eye treatments.

This means that according to the Theropeutical Good Adminstration (tga) that levels above 35ppm of Boronic Acid is considered unsafe for human use and illegal for use in Australia. I have no reference to their findings or research, however this is a concern.

oops bad math.... 0.035% = 350ppm

 

[chem geek]

This post goes more into borates safety. In the U.S., boric acid eye solutions are at 1-2% (1750 - 3500 ppm) and they do not require a prescription. The limit for pools is a little more than 50 ppm using a Margin of Exposure (MOE) safety margin of 100 and assuming 7-10 year old swimmers ingesting 38 ml per day drinking this every day for months. As noted, an infant would need to drink 1 tablespoon per day to reach this limit. And again, the limit has a safety factor of 100 since no specific tests were done on humans -- the highest No Observed Adverse Effect Limit (NOAEL) is based on studies in dogs.

Your math is probably wrong because the % is probably a weight % for boric acid while ppm is measured using the molecular weight of Boron. 0.035% boric acid would be 1000000*(0.035/100)*10.817/61.83 = 61 ppm.

 

[Brakel]

Thanks for the unit conversion, and info, I had read that thread and the testing on dogs and other testing done on rats, I haven't found any human studies but I beleive there have been conditions diagnosed as a result of boron exposure however I an yet to see documentation of the cases.
Human and dog tolerances can be extremely different. A finding that boron is toxic to a dog can only suggest that there is a possibility of it also being toxic to humans. A 100 factor or not, its guessing at best.

From what I have been told, pregnant women are at most risk, with development issues later in life for their unborn. going on the consumption/weight theory..... it wouldn't take much at all would it?
BTW, S4 in Australia is not Prescription medicine, its Pharmacist Only medicine, meaning its sold over the counter by a pharmacist

How long have people been using boron in pools at levels of 30-50ppm?
Is it realistic to think a small child could not consume more than a tablespoon of pool water each day?
Assuming a child was in a 50ppm boron pool for an average of 2h/day, how much boron would they consume via eyes, ears, broken skin, tongue, swallowing, inhaling, or any other method?
With a half life of 50%, boron levels in the body would compound quickly, at what level does it start to cause kidney damage?

assuming 7-10 year old swimmers ingesting 38 ml per day drinking this every day for months

my kids are likely to swim almost every days, 4 to 5 months of the year.

 

[chem geek]

In the post I linked to above I gave links to summaries of the known science that should answer your questions - see this link and this link. There wasn't significant dermal absorption and the available human exposure data gave lethal limits of 640 mg/kg for oral exposure, 8600 mg/kg for dermal exposure, and 29 mg/kg for intravenous exposure (see section 8.1.1 in the first of the two links for more info including accidental human overdose exposures). Overall, clinical symptoms weren't seen until ingesting 100 mg (at the lowest) which at 50 ppm would be 2 liters of pool water.

Read section 6 in the first link for how the body processes and excretes boron.

Basically, if you've got a dog that drinks cups of water every day from the pool, then you should think twice before using Borates (or train your dog to drink from a dish instead). As for people, the risk is much lower though as you point out (and so does the EPA) the risk is greater for small children or infants due to lower body weight.

There are several Borate swimming pool products including Proteam Supreme [Plus] and BioGuard Optimizer [Plus].