One of the most dangerous mistakes in janitorial and cleaning work is mixing incompatible cleaning chemicals. What may seem like a simple attempt to make a cleaning product “stronger” can create a dangerous chemical reaction within seconds. Certain combinations of common cleaning chemicals can release toxic gases, produce intense heat, cause fires, or create other hazardous substances. For example, mixing chlorine bleach with acids can release chlorine gas, while mixing bleach with ammonia-containing products can produce toxic chloramine gases. These gases can irritate or severely damage the eyes, skin, and respiratory system and, in serious exposures, can become life-threatening. A cleaning employee should never mix products unless the manufacturer specifically states that the combination is safe.