If you experience any dizziness or lightheadedness while working in the room, leave immediately, call 100, and report to the Medical Department to be evaluated. In general, keep the time working in environmental rooms to a minimum. Notify a coworker if you are using the room alone for more than a few minutes. These rooms have either limited mechanical ventilation and rely on opening and closing the door to change the air in the room. Acids can corrode cooling coils in the refrigeration system causing Freon leaks.
Asphyxiant gasses can displace oxygen in the room due to the low ventilation rate.
Storage of large quantities of dry ice in freezer rooms can release carbon dioxide and lower oxygen levels. Environmental rooms need to be specially designed in order to conduct chemical work. The contained atmosphere in environmental rooms and recirculation of most of the air creates a potential for retaining any aerosols that are formed during research procedures. This can lead to cross-contamination of research projects and personnel exposure. Keep these rooms as clean as possible.