A dyeing machine operator must have a keen eye and be able to differentiate between colors that are so similar so as to be almost identical. Operators must have a working knowledge of chemistry and materials science, and understand how to modify detergents and dye solutions based on the fabric in question; they must also understand how various chemicals interact with one another. If an unwanted reaction occurs, the color and strength of the dye solution may be dramatically skewed; in more serious situations, volatile chemicals may combine and produce potentially lethal gases in a matter of seconds. Machine operators must understand how to safely mix dyes and detergents, and how to safely operate all of their equipment. Furthermore, they must be able to take in information from diverse sources, prioritize it and act accordingly. A Dyeing Machine Operator must also be able to multitask in a high-pressure, high-noise environment; he or she will likely have to work simultaneously with several batches of fabric without confusing data between them. This aspect of dye machine operation is somewhat like chess; it requires monitoring multiple items and thinking far ahead to developments that may or may not actually happen. Dyeing machine operators should be in good physical condition, without arthritis in the hands or knees. Some operators can sit throughout most of the process, but others find themselves constantly standing, moving, and walking around their machines to observe the dyeing and check for malfunctions. Quick reflexes and dexterity are also valuable in these positions.