The document discusses the potential health hazards of bleach if not used properly. It states that inhaling bleach fumes can cause respiratory issues and irritation. It can also produce a harmful gas if left for long periods of time. Further, mixing bleach with other cleaning chemicals can create toxic fumes. The document warns that bleach is a known water pollutant and its byproducts such as dioxin are linked to cancer and other health problems. Proper ventilation is important when using bleach to avoid these health risks.