Across the U.S. there seems to be an endless variety of confined spaces; some complicated, others quite simple. When it comes to ensuring the safety of entrants, it seems that the simpler the space, the greater the danger.
This is a topic we stress in our Confined Space Train the Trainer courses. When you are dealing with pits and vaults, they can seem quite innocent compared with process vessels or boilers. Clearly, no one is going to try to go into a boiler (or fuel tank or process vessel) when it is operating, but a pit or vault? You can often see the bottom and it looks so accessible. If you accidentally dropped a tool or your phone into it, what's the problem with just jumping in to grab it?
While students in our classes understand that this would be a bad idea, do all the workers at your facility know it? We're not talking about those who have been trained in permit space entry, we are talking about those that haven't.
Several years ago Oregon OSHA published a hazard alert that focused on asphyxiation in pits. It describes several incidents that occurred in shopping malls. Workers went into poorly-ventilated pits to adjust the fountain valves and (you guessed it!) were overcome by low oxygen levels.
Pits and vaults are a perfect example of a simple confined space that contains an invisible hazard. When you combine that with workers who haven't had any exposure to confined space safety, you are setting the stage for an accident.
Under the federal confined space rules, employers must prevent inadvertent entry. Since the confined space standard is a performance standard, employers can decide how to best meet this requirement. Signs and/or using special locks are a common method.
When Oregon OSHA updated their confined space rules several years ago, they required employers to provide basic awareness training to everyone who works around confined spaces. (They did exclude anyone whose exposure was minimal such as an office worker who walks past a storm sewer in the parking lot.)
We believe awareness training is a sound practice, particularly as it relates to simple confined spaces that do not seem to have a hazard. These are the ones that look safe, and looks can kill.