18 Aug 2017

Chloramines – The Hard Truth

Do you recall fond Summer memories when you get a whiff of Chlorine around a pool? Ever get off an elevator at a hotel and knew straight away that the pool was on that level? We all know that Chlorine is added to pool water as a disinfectant to protect our health but most of us don’t understand that the ‘Chlorine pool smell’ is not due to Chlorine, but to;

Chloramines (Combined Chlorine)

Chloramines are chemical by-products formed when Chlorine reacts with substances such as urine and sweat and can build up in pool water when improperly treated. These Chloramines come in various chemical forms called Monochloramine, Dichloramine and Trichloramine. Trichloramine, in particular, is considered quite toxic and is most likely to exist in vapour form directly above the water surface where swimmers are breathing.
What’s the fuss all about?

Not only are Chloramines poor disinfectants, they irritate mucous membranes and cause exposed swimmers to suffer with stinging red eyes and itchy skin. Respiratory and Asthma problems related to Chloramine exposure are also common amongst regular swimmers.


To limit the formation of Chloramines, pool operators should advise swimmers to use the toilet and shower before entering the water to decrease the amount of contaminants entering the pool. This is particularly an issue for swim schools who have large numbers of infant swimmers that are not toilet trained.

Legally, to protect the health and safety of swimmers, combined Chlorine levels (Chloramines) must not exceed 1ppm in any public swimming pool or spa. If levels rise higher than this, Chloramines must be removed by adding more Chlorine or by using Ozone/UV technology or a combination of the two (AOP). When combining Ozone and UV the end result is Hydroxyl Free Radicals, one of the most reactive agents known to chemistry. These reactive species can virtually oxidise any compound found in water, maximising disinfection whilst killing all types of bacteria, fungi, virus and Chlorine resistant parasites such as Cryptosporidium. More importantly, these AOP systems will dramatically lower combined Chlorine levels to keep water within health regulations.

Use your senses/common sense

Facility managers are responsible for maintaining adequate pool chemistry however you can also use your senses/common sense to decide for yourself if the pool is safe to swim in:

  1. Does the water look clear, can you see the bottom?
  2. Do the pool surfaces feel slimy?
  3. Is there a strong Chlorine odour? Does it irritate your sinuses or cause you to cough?
  4. Always avoid getting water in your mouth and don’t swallow if you do!
  5. Always shower before entering the pool to reduce the amount of contaminants that may enter with you.
  6. Encourage kids to take regular bathroom breaks and do not go swimming if you have been ill or have Diarrhoea.