The atmosphere of the confined space shall be tested to be certain that: the oxygen level is at least 19.5%, but not greater than 23.5%, there is a hydrogen sulfide level of less than 10 parts per ...

An employee at an eastern Colorado sugar plant died, and five others were treated at a hospital after they were likely exposed to hydrogen ... were rescued from a confined space about 10 feet ...

Around 4:20 p.m. Thursday, the facility had a leak of hydrogen sulfide — a colorless ... Its presence makes work in confined spaces potentially dangerous partly due to it being heavier than ...