Bromine or Chlorine - is either one "healthier" for you

mrgreen

Member
Aug 24, 2010
8
I have read about the potential negative aspects of the chemicals (carcinogen?) - but haven't seen anything comparing the solutions to one another.

I am very concerned about carcinogens. Is one of the two "less risky"? Is there anything else I could be doing to minimize the potential risk?

I realize this probably isn't a question that could be answered easily (or I would be able to find answers on google) - but would appreciate any insight that the experts here can offer. Thanks in advance for the help.
 

mrgreen

Member
Aug 24, 2010
8
I am currently using 2 Beachcomber products.

bromo blast
sodium dichloro 52.7%
sodium bromide 14.6%

bromine disc
1-bromo-3-chloro-5 94%
bromine content 62.4
chlorine content 25%
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
Generally speaking, the brominated organics are more troublesome than the chlorinated ones. I list some of the ones the EPA notes below for chlorine and bromine (or combo) compounds:

Chlorine alone
Chloroform (CHCl3) -- EPA lists this as a carcinogen "likely under high exposure conditions"

Bromine or combination
Bromoform (CHBr3) -- EPA lists this as a "probable" carcinogen
Dibromochloromethane (CHBr2Cl) -- EPA lists this as a "possible" carcinogen
Dichlorobromomethane (CHBrCl2) -- EPA lists this as a "probable" carcinogen

Very roughly speaking, at the same concentrations, bromoform is more than 30 times as carcinogenic as chloroform while the dibromochloromethane and dichlorobromomethane are about 10 times more carcinogenic than bromoform. One in 1 million lifetime cancer risks for drinking 2 quarts of water every day are at 130 ppb for chloroform, 4 ppb for bromoform, 0.4 ppb for dibromochloromethane and 0.6 ppb for dichlorobromomethane.

This is why sanitation systems for drinking water try and remove organic particulate matter prior to chlorination to reduce the disinfection by-products and why they use chlorine and not bromine for disinfection (chlorine is also less expensive).

This paper measured levels of the disinfection products (in many pools, but we're not interested in that here and) in one commercial spa at 16.2 ppb for chloroform, 1.12 ppb for bromoform, 0.605 ppb for dichlorobromomethane, and below detection limit for dibromochloromethane, but this was for a chlorinated spa and it would be expected that a brominated one would have higher levels of the brominated compounds. Since the amount of disinfection by-products is roughly proportional to bather load, the amounts will probably be somewhat lower in a residential spa. The actual route of exposure is primarily inhalation since you aren't drinking the spa water, but there aren't measurements for concentrations of these volatile organics in air above the spa nor in cancer risk limits for that route (except for chloroform at 0.04 µg/m3 for 1 in a million lifetime cancer risk for constant exposure).

To minimize risk, you can start your soak with a minimal amount of sanitizer (1-2 ppm FC) and add more after your soak in sufficient quantity to oxidize bather waste. This is easy to do when using the Dichlor-then-bleach method (as described in Using Chlorine in a Spa). One should also uncover the spa for at least 10 minutes prior to soaking in order to air out any buildup of gasses accumulating under the cover. Note that if you do not soak with sufficient sanitizer then there is risk of person-to-person transmission of disease but if it's just you or your family in the tub then the risk is low.

There are also two non-halogen (i.e. no chlorine nor bromine) approaches that are more expensive: Baquacil and Nature2 with MPS. The latter is less problematic and uses chlorine "as needed" to keep the water clear, sometimes once a week, while non-chlorine shock (MPS) is used as the primary oxidizer/sanitizer when used in conjunction with silver ions from Nature2 (this only works to be sanitary at hot spa temperatures).
 

mrgreen

Member
Aug 24, 2010
8
Wow - this is amazing info.

Those are great suggestions. I will be switching to Chlorine - and will start looking for someone that carries the Nature2 product in BC Canada.

Thanks again!
 

svenpup

LifeTime Supporter
Nov 18, 2009
835
Sacramento, CA
mrgreen said:
...I will be switching to Chlorine - and will start looking for someone that carries the Nature2 product in BC Canada...
We don't recommend Nature2 either because of the staining issue from copper.

You should read:


There is a reason that we preach chlorine (from bleach/liquid chlorine or SWCG in sufficient concentration based on a CYA) and not any alternative "sanitizers".

If you want a long term viable solution that allows you to maintain slightly lower FC levels than SWCG is your option.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
This is a spa we are talking about, not a pool. Nature2 for pools isn't very effective and risks staining from both silver and copper ions, but Nature2 for spas doesn't add copper; it only adds silver and a small amount of zinc. Spas are less likely to get stained as they are not usually plaster and the water is changed more frequently. Nature2 with MPS is only an EPA approved sanitizer for spas, not pools, because hot water temperatures are required for this combination to pass EPA DIS/TSS-12.

I think that Dichlor-then-bleach is the best approach for spas as it is readily controlled, is inexpensive, and is easy, but if someone has to have a non-halogen approach, then Nature2 with MPS is a reasonable alternative (though only for spas), albeit much more expensive.
 

mrgreen

Member
Aug 24, 2010
8
More great info! Lots to read and consider.

For now, I think I need to move from my bromine solution listed above - to the "Dichlor-then-bleach" solutions that I have read throughout this site.

I plan to drain the tub to do the conversion. I figure I'll drain, then refill enough to run the pumps (to clean it out) then drain again... to ensure I'm starting fresh.

Is there anything else I need to do - or should be worried about when converting?
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
No, that's it, though you might as well do a super-chlorination after your first drain/refill just to be safe. That's described in the Using Chlorine in a Spa (in the Introduction) I linked to earlier.
 

Pecos Bill

New member
Sep 12, 2011
3
chem geek said:
This is a spa we are talking about, not a pool. Nature2 for pools isn't very effective and risks staining from both silver and copper ions, but Nature2 for spas doesn't add copper; it only adds silver and a small amount of zinc. .... albeit much more expensive.
Thank you for posting this clarification. I feel better about using Nature2 Spa. For someone who is willing to test their spa daily (as said elsewhere by Nitro, I think), that's a fantastic solution. With my hectic life, I need something that can work when I'm not around — and no, I don't want a "pool boy." Though I hope there's no risk, I've found the cartridges for Spas online at around $16 each which isn't bad over the 3 to 4 month span they are good for.

Pecos Bill
Spa Stored :hammer: too many times until finding this :whoot: .
 

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