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QID - 27497 Which statement about entering into a tank which has been sealed for a long time is TRUE? If the oxygen content tests at less than 12% you should wear an approved gas mask.
The tank should be tested only once to ensure the oxygen content is at least 14% before entry.
The tank need not be tested for oxygen content if it is ventilated for more than 24 hours.
The tank must be tested at frequent intervals to ensure that hazardous gasses have not regenerated.
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