Dangers of confined spaces

[Stephen Lagueux]

Situation; Older house, gas appliances, unvented crawlspace. Inspector walks in to do his job, gets in the crawl space, passes out and dies. What happened?

Many scenarios are possibles. From physical hazards to hazardous atmospheres, confined spaces and espacially crawl spaces can pose many risks to the inspector.

Among the possible danger sources we can find rodents, insectes nests and other dangerous animals. Miscellaneous construction materials, electrical hazards, chemicals, sharp objects etc. We are pretty much all aware of the visible dangers and we don't give it much toughts. But how about the danger that we don't see?

What if one gets in a crawl space and there is an open sewage line? How about mal fonctionning gas appliances? Both situation can lead to accumulation of carbon monoxyde to levels that can be lethal. Without talking about the other toxic and explosif gases, there could really be dangerous situations out there.

Stretching the idea some might say? Maybe, but as low as the odds might be, the possibilities still remain and it only takes one time. 90% of injuries or fatalities associated with confined spaces are atmospheric in nature and 47% of confined spaces deaths is from asphyxiating.

Who in here has really thought about the dangers related to lack of oxygen or presence of toxic gases in confined spaces?

[Bill Kibbel]

What if one gets in a crawl space and there is an open sewage line? How about mal fonctionning gas appliances? Both situation can lead to accumulation of carbon monoxyde to levels that can be lethal.

I don't recall sewage being a source of carbon monoxide. "Sewer gas" would contain methane, hydrogen sulfide, sulfur dioxide, carbon dioxide, & ammonia.

I had NIOSH confined space entry training about 30 years ago. It's been helpful for some of the industrial building inspections. There are times when I wear my 3-gas alarm for industrial and some commercial inspections and it's alerted me to issues several times.

A residential crawl space is not one area I'm concerned about. I can't imagine any situation where there would be an issue with deadly air contaminants that wouldn't be suspected before entry. I'm far more likely to get electrocuted or fall in a hand-dug well in the crawlspaces that I get.

[Stephen Lagueux]

There are times when I wear my 3-gas alarm for industrial and some commercial inspections and it's alerted me to issues several times.

I was wondering if some were using gas alarms. I might get one too, perhaps just a monogas though.

I don't recall sewage being a source of carbon monoxide

I'm reading this from an IICRC formation book, it says it's present in sewer system and septic tank but that could be a mistake, I'll check it out. From what I see, sewage could displace oxygen and that could pose a hazard too I guess.

[John Kogel]

Propane gas could be a serious hazard. A construction worker blew up a metal storage container here about a months ago. There was a leaky propane cylinder in the container. When he opened the door, the blast sent him flying and windows were blown out all over the block.

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Methane gas is also explosive to a lesser extent. But the smell would be obvious, I would think.

Sorry, Stephen, you want to stick to noxious gases. Yes, utility workers crawl into sewers and pass out quite often.

[kurt]

Methane gas is also explosive to a lesser extent. But the smell would be obvious, I would think.

I thought methane was odorless & colorless. That's why they needed the canary in the coal mine.

While looking it up, I came across this in a coal mining related site....

A "black damp" is a mix of carbon dioxide and nitrogen caused by corrosion, a process that can cause suffocation by drawing the oxygen from the air.

An "after damp" includes the same gases as a black damp, plus carbon monoxide, and usually forms after a mine explosion.

A "fire damp" is particularly dangerous, because it consists mainly of methane, a flammable gas.

A "stink damp," which reeks of rotten eggs, is mostly hydrogen sulfide. This gas, too, can explode.

A "white damp" is any air containing carbon monoxide, a gas that has no discernable scent but is toxic in even low concentrations.

On occasion, I am a source of toxic gas in enclosed spaces (my Carharts)....it sometimes has me wondering if I'm getting out alive.

[Jim Katen]

It's cool & exciting to think about all of the zebras, but the horses are much more likely to get you.

[Jim Morrison]

What you're hearing now is the sound of me gnashing my teeth that Katen posted it before I did.

[Tom Raymond]

On occasion, I am a source of toxic gas in enclosed spaces (my Carharts)....it sometimes has me wondering if I'm getting out alive.

I did that riding the chair lift while skiing with my boy and declared it a seat warmer. It's amazing, but he still rides with me.

[John Kogel]

Methane gas is also explosive to a lesser extent. But the smell would be obvious, I would think.

I thought methane was odorless & colorless. That's why they needed the canary in the coal mine.

You are correct. I was thinking the smell of sewer gas from a broken pipe should be obvious, but if only methane gas is present, yes, you need to pack a canary with you.

I wonder if flatulence has ever killed a canary? Might want to provide him with a little gas mask, come to think of it. []

[Stephen Lagueux]

I don't recall sewage being a source of carbon monoxide

carbon monoxide COULD be present in sewer systems as a byproduct from the combination of other gases.

[Jim Katen]

I don't recall sewage being a source of carbon monoxide

carbon monoxide COULD be present in sewer systems as a byproduct from the combination of other gases.

I'm curious. Which gases combine to form carbon monoxide in sewer gas?

[gtblum]

Here. All you need to do, is get training, follow the rules, keep proper documentation of the entry, hire a trained attendant and have a rescue crew in place before the dive. Piece of cake. I used to have to re-qualify every year at the nuke plants.

Can't be too much different on your side of the river.

[Jim Baird]

I used to inspect and write housing rehab jobs for owner occupied dwellings, Under one, with a failing floor system and a too short for good sense crawl, I saw framing members sagging within inches of my nose as the hugely obese occupant, who walked with a very pronounced limp, lurched back and forth above me. It did occur to me that I could be crushed like a roachbug down there and not be found for a while.

[resqman]

Was a member of a confined rescue team for about a decade. Held national certifications in confined space rescue, trench rescue and hazard materials. Regularly trained in permited confined spaces in full rescue gear. Commerical and Industry hired the rescue team to standby fully suited up while union workers modified vats, tanks, silos, etc. Respirators, SCBA, full harness, backup systems, gas monitors, etc. All of us were at least EMT with several being Paramedics.

I have thought about writing a class for home inspectors regarding entering confined spaces, potential injuries, self-rescue, hazards, etc. Just never get around to it. NIOSH prints a book of confined space deathes. Most common death after the inital victim is the first "rescuer" The first person to see their co-worker, family member, or just fellow human lying unconcious in a confined space rushes in to help. They fall victim to what ever overcame the first victim. There are many stories of a a pile of bodies in a confined space as more and more well intentioned but inadequately equipped people rush into help.

Are crawlspaces and attics unpermitted confined spaces? You betcha. And full of hazards with explosive gases being just one of them.

So, Yes I have thought about confined spaces and the assoicated danagers...

Here is the webpage for the rescue team I was a member of. www.redsteam.com

Confined Space Information

http://redsteam.com/team/?page_id=76

[Jim Baird]

BTW I have twice found hand dug wells in crawl spaces. Both were so old that their concrete caps had fallen into the void. It's why I always crawl belly-down, so I can see in front of me.

[Stephen Lagueux]

I have thought about writing a class for home inspectors regarding entering confined spaces, potential injuries, self-rescue, hazards, etc. Just never get around to it.

Are crawlspaces and attics unpermitted confined spaces? You betcha. And full of hazards with explosive gases being just one of them.

So, Yes I have thought about confined spaces and the assoicated danagers...

Here is the webpage for the rescue team I was a member of. www.redsteam.com

Confined Space Information

http://redsteam.com/team/?page_id=76

If I were you, I'd definitely do it. As per OSHA, a crawl space is not considered a confined space BUT, it falls under the general duty clause. Therefore, employers must train for the hazards employees can encounter.

For the major inspection companies out there that hire dozens of inspectors and perform thousands of inspections per year, it only takes one incident to kiss your company goodbye...

[Tom Raymond]

For the major inspection companies out there that hire dozens of inspectors and perform thousands of inspections per year, it only takes one incident to kiss your company goodbye...

Where are these companies? What do they pay? And, are they hiring?

[Jim Katen]

I fully understand that their are serious risks associated with confined spaces and I don't mean to trivialize them, but I've got to ask: Is anyone aware of a home inspector anywhere or anytime who's died in a crawlspace as a result of these exotic scenarios?

[John Kogel]

I fully understand that their are serious risks associated with confined spaces and I don't mean to trivialize them, but I've got to ask: Is anyone aware of a home inspector anywhere or anytime who's died in a crawlspace as a result of these exotic scenarios?

I don't know about inspectors, but somebody's best friend certainly died. []

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