is chloramines called combined chlorine
Chloramines are a type of combined chlorine that form in water and then off gas into the air above the water. Most city, county, and state health departments limit the amount of combined chlorine in the water to 0.4 ppm or less. Chloramines can build up in the water, which means they can build up in the air if there is not enough fresh air surrounding pools and other places people swim in chlorinated water .