The US-American Occupational Safety and Health Administration (OSHA) has
produced a grain handling hazard card warning of the danger of being buried
and suffocated when entering grain storage bins. The laminated wallet-sized
card lists the OSHA-required precautions that must be taken whenever workers
enter a grain storage bin. These include turning off and locking out augers and
any other powered equipment in the bin, entering from a level at or above
stored grain using a body harness with an anchored lifeline or boatswain chair,
and testing the bin's air to ensure there is enough oxygen and no hazardous
gas.

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AplusA-online.de - Source: Occupational Safety and Health Administration