Confined spaces and OSHA 1910.146: 10 examples to train in VR

The rule puts someone outside

The NIOSH figure is from 1986 and still holds: the atmosphere that knocked out the first person is waiting for the second.

That is why 1910.146(i) gives the attendant one position: outside the permit space for the whole entry, until another attendant takes over. From there they track who is inside, summon rescue and perform non-entry rescue with the retrieval line. They only go in if they are trained and equipped for rescue and someone else takes their post.

It is the one job in the operation whose most important task is not doing what the body is asking for.

Permit-required or not, the meter decides

Under 1910.146 the question is not what the space looks like, but what it contains or could contain:

Criterion	Non-permit space	Permit-required space
Atmosphere	No potential hazardous atmosphere	Oxygen below 19.5% or above 23.5%, or flammable gas above 10% of the LFL
Engulfment	None	Material that can engulf an entrant
Configuration	No trapping shape	Inwardly converging walls or a floor that slopes to a narrower section
Other hazards	None that can kill or seriously injure	Any other recognized serious hazard

The same tank can look harmless on Monday and be deadly on Thursday. That is why the air is tested before every entry, and during the work.

10 permit-required confined spaces and what is practiced in VR

None of these is permit-required by definition. This is what usually makes them so, and this is what gets practiced for each one:

1. Storage tanks. Empty is not clean: the vapors stay. In the headset, the multigas meter picks them up.
2. Grain silos and hoppers. Fermentation eats oxygen and grain can engulf. In the headset, the reading drops with someone inside.
3. Septic tanks and sumps. Hydrogen sulfide stops being smellable at high concentrations. In the headset, the alarm goes off even when nothing smells.
4. Manholes and sewers. Gases travel through the network. In the headset, the reading changes without anyone touching anything.
5. Nitrogen-inerted tanks. Nitrogen is odorless and colorless, so it gives no warning. In the headset, you test before you trust.
6. Reactors under maintenance. A residue or a line nobody locked out. In the headset, each isolation is checked against the permit, as in lockout tagout training and VR for industrial safety.
7. Boilers and furnaces that are off. Off is not cold: carbon monoxide and heat remain. In the headset, you test and ventilate before entering.
8. Ducts and service tunnels. The atmosphere changes with the work inside. In the headset, welding forces continuous monitoring.
9. Tanker trucks and railcars. They carry vapors from the last load. In the headset, every attempt brings a different load.
10. Dust collectors. Accumulated dust can burn or explode. In the headset, a sparking tool forces the work to stop.

The rescue drill 1910.146 requires and almost nobody runs in full

On paper, the rule is met. In practice, a full drill means shutting down, ventilating and emptying the tank, and even then the real emergency never shows up: the meter going off, the radio going silent and the urge to climb down.

When the inspection comes, what is left is the training certificate. It proves people sat through the course, not that they know what to do when the alarm sounds.

What the rule asks for and what the simulator covers:

What OSHA 1910.146 asks for	How the simulator covers it
Training before the first assignment (g)	In your modeled space, with unlimited attempts
Training certification (g)	Critical failures and a score per person
Rescue practice at least every 12 months (k)	Unannounced events, without shutting down or emptying the tank
Atmospheric testing before entry	Readings that change on every attempt
Entry permit (f)	The permit is filled out field by field
Retraining when duties or hazards change (g)	Repeated without stopping operations

How it is practiced in a custom simulator

The participant goes through the procedure by role in your own tank, pit or sump, and if someone climbs down to rescue, the scenario takes them back to the point where they had to decide.

Every attempt is recorded per person: answers, errors, critical failures and time, in an exportable file. It runs without internet or controllers, and the instructor follows the session live. You own the development: there is no per-headset license.

This is how we build custom industrial training.

The entry permit, the employer's training certification and the drill with real equipment stay with you. The attendant arrives at that drill having stayed outside dozens of times.

Your attendant is going to hear that silence on the radio one day. The only thing you get to decide is whether the first time they stay outside happens in the headset or in your plant.

Frequently asked questions

What is a confined space?

Under OSHA 1910.146, a space large enough to enter, with limited entry or exit, not designed for continuous occupancy. It does not have to be small or underground: a silo or a tanker truck qualifies.

What is a permit-required confined space?

One that has or could have a hazardous atmosphere, engulfment, a trapping shape or another serious hazard. In Fyware's simulator, readings change on every attempt, so nobody classifies from memory.

What does a confined space entry permit include?

Fifteen items, from the space, entrants, attendant and supervisor to hazards, isolation, test results and rescue. In Fyware, the simulator scores each participant and delivers a results table per person.

What does a confined space attendant do?

Stays outside during entry, tracks who is inside, summons rescue and performs non-entry rescue. In Fyware's simulator, the entrant stops answering and the attendant has to do exactly that.

How often is confined space rescue training required?

In-house rescue teams must practice permit space rescues at least once every 12 months. In Fyware's simulator, the rescue is repeated without shutting down the tank.

What is a confined space simulator?

Your space recreated in virtual reality, where mistakes are part of the training: if someone climbs down, the scenario makes them pay for it. Fyware builds it to order from photos of your space. See in Fyware Safe how the fire, PPE and forklift simulators look.