Confined space entry begins when an employee fully enters the confined space.

In regard to exposure of blades, when the blades of a fan are less than seven feet above the ground the blades shall be guarded.

Affected employees are trained to perform lockout/tagout.

DART _______ DAFWI

It is good practice to use emergency stops (E-Stops) to lockout a machine as they effectively stop the machine from running.

How does OSHA compare the relative safety performance companies of different sizes (number of employees)?

“Loudness” is a function of sound intensity, which is a function of                                                  pressure squared (I

In this figure, where the chain meets the sprocket is known by safety professionals as:    

The following question refers to this scenario. Two experienced railroad foremen died after entering a railroad tank car that had been involved in a derailment at another location. Both victims worked for a company that specialized in refurbishing and repairing railroad equipment. The empty railroad tank car had been filled with soybean oil, and the headspace (unfilled volume) inside the tank car was filled with a cover gas (in this case nitrogen) to prevent spoilage. At the time of the incident, the tank car did not have any permanent or temporary exterior warning signs or markings to alert workers that a hazardous atmosphere was present. The first victim was attempting to assess the extent of repairs from inside the tank car. He used a portable multi-gas meter to measure the air quality inside the car and reported to a co-worker accompanying him (attendant) that the air inside was okay. He then entered the tank car through the top hatch, while the attendant stayed just outside. Noticing the victim collapse a short time later, the attendant called 911 and radio-ed for help from the company. While emergency help (the confined space rescue crew) was en route (on the way), a second foreman (second victim) arrived at the scene. The second victim immediately asked the attendant about the air quality inside the tank car and was told by the attendant that the air inside was okay. The second victim then entered the tank car. Once inside the car, the second victim almost immediately collapsed. Emergency personnel arrived moments later. They first checked the air inside the tank car with their equipment and found little or no oxygen inside. Then rescuers donned appropriate respiratory protection and extracted both men, who had died from asphyxiation. How might the error have been made regarding the tank’s atmosphere?

An oxygen deficient environment (O2 < 19.5%) presents a hazard to workers.  However,  an oxygen enriched environment (O2 > 23.5%) can also present a hazard in a confined space.