Combined Chlorine (Chloramines)

The owner shall ensure the AQUATIC facility takes action to reduce the level of combined chlorine (chloramines) in the water when the level exceeds 0.4 PPM(mg/L). Such actions may include but are not limited to: 1) Superchlorination; 2) Water exchange; or 3) Patron adherence to appropriate BATHER hygiene practices.

Combined CHLORINE compounds (chloramines) are formed when FREE AVAILABLE CHLORINE combines with amine-containing compounds such as urea, amino acids, and ammonia from perspiration and urine. Chloramines include inorganic compounds (monochloramine (NH2Cl), dichloramine (NHCl2) and trichloramine (NCl3)) as well as a variety of organic compounds. Inorganic chloramines are biocides, but are much less effective as quick kill disinfectants than FREE AVAILABLE CHLORINE. If the local water treatment plant uses chloramination for drinking water DISINFECTION, inorganic chloramines (predominantly monochloramine) may be present in the fill water. High Chloramines A high level of chloramines is undesirable in AQUATIC VENUES. The action level for combined CHLORINE is 0.4 PPM (mg/L). Higher levels indicate that bathing loads or pollution from BATHERS may be too high, or that treatment is inadequate. Higher levels may also pose a health concern to BATHERS, employees, and other PATRONS. The World Health Organization recommends that combined CHLORINE levels be “as low as possible, ideally below 0.2 mg/L”³⁷⁸. However, this “ideal” level would be challenging to implement as a CODE requirement. Since the combined chlorine values reflect the combination of inorganic (well demonstrated health effects) and organic (poorly understood relationship to health effects) chloramines, the MAHC has decided to work with an “action” level until they can be differentiated. Development of tests that can measure the inorganic chloramines separately from the organic chloramines is needed so actionable levels can be set. With such tests, aquatics staff will be able to respond to actionable levels of volatile chloramines so appropriate air quality can be maintained. The separate measurement of organic chloramines, which accumulate in the pool, may be a useful marker for the need to replace water or supplement with a system known to remove these compounds. Published data are limited, but suggest that combined CHLORINE levels are commonly above 0.2 PPM (mg/L) in swimming POOL water³⁷⁹, ³⁸⁰, ³⁸¹. Inorganic Chloramines Volatilization of chloramine compounds can lead to strong objectionable odors in AQUATIC VENUE environments, as well as eye, mucous membrane, and skin irritation for BATHERS and PATRONS. Among the inorganic chloramines, NCl3 has the greatest impact on air quality, owing to its relatively low affinity for water and its irritant properties. NCl3 has been reported to be an irritant at concentrations in water as low as 0.02 PPM (mg/L). Odors are unlikely to be present from inorganic chloramines below the following concentrations: * Monochloramine (NH2Cl): 5.0 PPM (mg/L) * DICHLORAMINE (NHCl2): 0.8 PPM (mg/L) * TRICHLORAMINE (NCl3): 0.02 PPM (mg/L) Research to understand the relationship between inorganic chloramine concentrations in water and their impact on air quality is limited, although some research indicates that the gas phase NCl3 concentration is dynamic and impacted by BATHER COUNT, swimmer activity, liquid phase NCl3 concentration. Reliable sampling and analytical methods affect the accuracy of the characterization of the AQUATIC VENUE water and air. Health Incidents Studies of swimming POOL users and non-swimming attendants have shown a number of changes and symptoms that appear to be associated with exposure to the atmosphere in indoor AQUATIC VENUES. CDC has intervened and investigated various health incidents reporting skin and eye irritation and acute respiratory outbreaks that could be associated with exposures to chloramines and other by-products at recreational water facilities, including swimming POOLS³⁸²,³⁸³. Lifeguard Exposure For lifeguards at swimming POOLS, an exposure–response relationship has been identified between NCl3, measured as total chloramines, and irritant eye, nasal, and throat symptoms, although not chronic respiratory symptoms or bronchial hyper responsiveness³⁸⁴. Respiratory Conditions In addition to potential occupational exposures, there have been a number of studies investigating respiratory conditions, including asthma, related to swimming pools. There appears to be no consistent association between swimming POOL attendance during childhood and the prevalence of asthma or atopic disease³⁸⁵, ³⁸⁶, ³⁸⁷. Studies indicate that asthma is more commonly found among elite swimmers than among other high-level athletes, although it is premature to draw conclusions about the causal link between swimming and asthma because most studies available to date used cross-sectional design, because the association is not confirmed among non-competitive swimmers, and because asthmatics may be more likely to select swimming as the activity of choice because of their condition³⁸⁸. Contact Dermatitis Chloramines have also been implicated in contact dermatitis (rashes). The number of rashes that occurs among BATHERS in treated recreational water is not known. One cross-sectional study of Australian school POOLS retrospectively examined the incidence rate of rashes in three POOLS. The three POOLS treatment types were 1) CHLORINE alone (hand dosing), 2) CHLORINE plus ozone (automatic dosing and control), and 3) bromine (sodium bromide plus ozone using automatic dosing and control). This study reported 14.4% of the BATHERS in the hand-dosed CHLORINE POOLS experienced rashes³⁸⁹. This and anecdotal reports strongly suggests that rashes are the most common RWI. The greatest number of rashes appears to be among hydro-therapists (aquatic physical therapists). A survey of 190 professional hydro-therapists in Israel reported that 45% developed skin disease after beginning work. Symptoms reported included itchiness, redness, dry skin. The areas affected were the extremities, the face and trunk, and folds in the skin. The authors concluded: 1) exposure to water influences development of irritant contact dermatitis; 2) cumulative exposure of low-potency irritants may be cause of contact dermatitis; 3) contact dermatitis is an occupational disease of hydro-therapists³⁹⁰. In these and similar reports, the exact chemical species inducing the contact dermatitis has not been identified but the collective opinions of the investigators is that halogenated organic compounds (DISINFECTION BY-PRODUCTS) is the cause. One conservative estimate places the number of halogenated DISINFECTION byproducts, including organic chloramines, in swimming POOLS at greater than 200. The clinical significance of these is likely to vary with the concentration of specific chloramine and BATHER specific factors (length of exposure, underlying health conditions, and cumulative previous exposure). Maximum Concentration After considerable discussion the MAHC decided to recommend an action concentration of 0.4 PPM (MG/L) for combined CHLORINE in all recreational waters. This recommendation is based on the desire to minimize the potential for both respiratory and dermal disease that is known to be associated with exposure to chloramines. The MAHC recognizes that this concentration is arbitrary and that it has not been substantiated by adequate human clinical studies. In the absence of an adequate human study, the MAHC has opted for a conservative value rather than a more lenient value of 0.5 PPM (MG/L) preferred by some operators. The key is that regulators start enforcing regular testing for combined CHLORINE so that POOL operators work towards keeping levels low by responding to this action threshold. Levels of chloramines and other volatile compounds in water can be minimized by reducing introduction of CONTAMINANTS that lead to their formation (e.g., urea, creatinine, amino acids and personal care products), as well as by use of a shock oxidizer (e.g., potassium monopersulfate) or supplemental water treatment. Effective filtration, water replacement, and improved BATHER hygiene (e.g., showering, not urinating in the POOL) can reduce CONTAMINANTS and chloramine formation. Shock dosing with CHLORINE can destroy inorganic chloramines that are formed. Some research shows that non-CHLORINE shock oxidizers reduce the propensity to develop chloramines. However, this research has not been peer-reviewed to date. The U.S. EPA has determined that manufacturers of “shock oxidizers” may advertise that their “shock oxidizer” products “remove,” “reduce,” or “eliminate” organic CONTAMINANTS * For more information, see: http://www.epa.gov/oppad001/shock_ltr.htm. Secondary Disinfection SECONDARY DISINFECTION SYSTEMS such as ozone and ultraviolet light may effectively destroy inorganic chloramines. As this also has a public benefit and can assist in meeting the MAHC requirements for combined CHLORINE, it is strongly recommended that any installation utilizing UV or ozone as a SECONDARY DISINFECTION SYSTEM consider the positive impact the equipment may have on reducing combined CHLORINE levels in addition to achieving DISINFECTION goals. To improve chloramine control strategies, future research should be aimed at: * Defining the fundamental chemistry of DISINFECTION byproducts including, organic and non-organic chloramine formation from precursor compounds that are common to swimming POOLS; * Defining relationships between levels of combined CHLORINE in water and air of AQUATIC VENUES and the adverse effects on POOL attendees, to include inhalation, ingestion, and contact; * Documenting efficacy of water treatment technologies to reduce chloramine levels; * Improve testing for combined CHLORINE in air and water; and * Testing for the components of combined CHLORINE.