2021 Model Aquatic Health Code (4th Edition)

ABSTRACT

The Centers for Disease Control and Prevention (CDC) will be releasing the 4th edition of the Model Aquatic Health Code (MAHC, www.cdc.gov/mahc) in the coming months. The MAHC represents a collaboration among local, state, and federal public health officials, particularly environmental health practitioners, and representatives of the aquatics sector to optimize prevention of illness and injury associated with public aquatic venues (e.g., pools, hot tubs, and water playgrounds). Cyanuric acid (CYA) binds to chlorine to prevent it from being degraded by UV light from the sun. Consequently, CYA increases the amount of time it takes for chlorine to inactivate pathogens. CYA is sold as a stand-alone product or as chlorinated isocyanurates (chlorine and CYA, commonly known as dichlor or trichlor). In 2015, CMAHC established a CYA ad hoc committee that included representatives from across the CYA industry and researchers but did not include state or local public health officials. CMAHC charged the committee to develop guidance on CYA concentrations.