Any condition that poses an immediate or delayed threatto life or that would cause irreversible adverse healtheffects or that would interfere with an individual'sability to escape unaided from a confined space. The personnel designated to rescue employees fromconfined spaces. C. hazardous chemicals above Permissable Exposure Limits. D. toxic substances that are known to have poisonousphysiological effects. The most common toxic gasesencountered are carbon monoxide and hydrogen sulfide.
Carbon dioxide is a by-product of fermentationwhich displaces oxygen.
Carbon monoxide is created by internal combustion. It can kill by replacing the oxygen in the bloodcausing unconsciousness. Sulfur dioxide has a sharp pungent smell that istoxic in small amounts. Hydrogen sulfide is part of many industrialprocesses that can cut off breathing once it enters the body. In higherconcentrations it can paralyze the sense of smell so its odor is notdetected.