Working today in a brick plant, I had noticed that it was hot, even hotter than usual. I was able to breath without too much irritation in my airways, so I went ahead and climbed down to the dryer fans and took the readings.

At the hot end of the dryer (where I had given myself a sunburned pinky toe through my boot before) I had to climb on the duct to bet into the well where the fan is located. When I got down and went to do the hydraulic pumps (real big mess), I looked at the right leg of my Tyvek coveralls and tried to straighten it out to keep the mess off. I found that the Tyvek had melted

That brought to mind 2 questions:

1. Is there an OSHA standard where protective clothing is required?

2. What is the melting point of Tyvek?

Thanks,

Danny

Doing a web search came up with this from one MSDS sheet...Melting point: 110-140° C (230-284° F) @ 760 mm Hg.

And this from another sheet 135° C.

John

tyvek_spunbonded_msds.pdf (15 Kb, 27 downloads)

The big worry is; how hot is it to your face? Heat is bad for eyeballs and can cause problems. If the air is too hot to breathe you can bet it's time to get out. Don't go alone - tie a rope around the pink toe and call a toe truck.

Sounds like the sort of job I'd have a buddy up top just in case.

Mike.

We used to collect data on rolls under the hood of a paper machine afterdryer section. It was so hot that you had to wear gloves and any jewelry or glasses you wore would burn you. I finally took a thermometer with me and held it in the air. The temp was 182 degrees F. We were literally cooking ourselves!!!!!!! Those rolls are now hardwired and we do not go there unless the machine is down.
Danny, you may want to consider hard wiring a few of those real hot data points. Even being a native Floridian, that sounds too hot for me.

Gary B

Hey Dan
Sounds to me like you are on slow roast.Looks like an application for permanent sensors. And until then you should be aware that you could pass out in these conditions and without a buddy you may not be found in time.I have seen where four of us where working up close to our press and three of us where ok and the third guy in a very short time turned white and was ready to pass out.we got down quick fast and in a hurry.PLease be careful if you have to go into thissituation again.

Thanks for the replies.

John,

Nice link to the msds. I find it hard to believe that I was breathing air that hot, so it makes me think that I was up against the duct work when it happened. I did have to clinb on one of the ducts and that is out of the ordinary. I'll check my boot soles, too. (If I can tell any new melting from the old steam pipe melts)

Sam,

I get it.... toe truck....very funny. If I hooked my life line to my pinky toe, that would probably be all of my mass that they would be able to haul out. Besides, I've got this blister.

No eyeball problems, but it was a little irritating to my throat.

Gary,

I also used to work under a dryer hood. We had about an acre of infra red heaters at the dry end and if they were running, it would give you a sunburn. I just might put accels on these fans if they can take the heat any better than me.

Lee,

Like Cheetoes I am quick-fried to a crackly crunch rather than baked to a delicate crunch. Fortunately, I only have to spend about 10 minutes in this area (2 fans), but I will take your advice seriously and talk it over with plant personnel before going back. Maybe they can make some sort of a short term change in the process while I am up there. I do enjoy this work, even the hot stuff. But I'm not willing to die to protect these fans.

One other point to keep in mind when working in hot areas is to drink water....lots and lots of water! Some of my former co-workers were on an aircraft carrier in the Indian Ocean in the summer time...a lovely place I assure you. Turns out if you are really sweating and not replenishing water, you'll lose muscle control and collapse like a rag doll. No fun at best and very dangerous at worst.

One of them had severl liters of saline by IV and was fine the next day. The other refused treatment and suffered for a week while his body returned to normal.


Jon
Spintelligent Labs

From the safety side of things, what are the guidelines for going in to a hot area? How hot is acceptable? Any agencies that give guidance?

I guess not more than 60 deg C. I worked in a reactor with 1200 deg C at its core flame before. Had to enter during shutdown for which the operations will ensure the temp is not dangerous to humans before entry & giving a work permit. Don't you need a work permit to take the vibration readings? I think normal plant insulation is designed to reduce temp to 60 deg C surface temp.

Coverall should be made of cotton or Nomax.

I am now convinced that this area is too hot.

On Friday, it was hotter than even before with the outside temperature and humidity higher-about 80 deg f and 90% humidity.

I'm not sure of how long I was in the area, but it was probably no more than 15 minutes. My respiration went way up as did my pulse rate and body temp. I'm not sure to what levels any of these rose, because I was addle-minded, also. I left the area before I got finished and took off my hard hat and coveralls and sat in front of a fan. Then I moved into an air-conditioned (sort of) office in the plant where there was cold water. I drank plenty, dumped it on my head, removed my boots and dumped it on my feet while my trainedd went to find ice. He returned with the ice and I put the bag on my head and moved it around to the various locations of maximum blood flow, backs of knees, neck, crotch, armpits, etc. My pulse rate and respiration were still high, but by this time (maybe 10-15 minutes) I had gotten it together enough to check them. Pulse was still about 130 and respiration about 70. I checked my temp in my ear with my Raytek Minigun and it was 98 where I usually get about 89-90. I began to throw up and decided that it was time to go to the hospital.

I got the standard treatment for heat stroke, iv fluids and packed in ice, even though by the time we found the hospital, my temp had returned to almost normal and my respiration returned shortly after my arrival. The doctor and nurses said that I probably wouldn't have cooled down as fast at the hospital, because they would not have so thoroughly soaked me as I did. (Made a real mess in the guys office, but lived to tell about it).

I still have a headache and am kind of weak, but will probably be back to normal by tomorrow or Tuesday.

Naturally, I can't resist the urge to collect some data to try to establish some criteria for how hot an environment we will work in. Since I know that this one is too hot, I'll use it as an example and make sure we stay safely below it. I have found some data on OSHA's website aobut heat stress that may be valuable reading for some of you. There is no OSHA standard, because there are too many variables, but there are some good guidelines and physical benchmarks. I found it in a site search and printed it, but didn't bookmark. I'll come back and post some links later.

If these fans need vibration analysis, then they need permanent accels, unless the airstream that they are in is too hot. If it is, then too bad about the fans, because I'm not going up there again for any longer than it takes to collect a temperature reading.

I'm also going to get radios for me and my trainee so that we can keep closer tabs on one another. I may consider a report to OSHA about my client, although that is usually not good for business. Being a brick manufacturer, you would think that they would be prepared to handle heat problems, but they were totally unprepared. No cold packs in the first aid kit, no way of transporting an affected individual out of the plant, no insulation around 400 degree duct work, and other safety issues. I value their business, but not enough to die for. Most of their employees are immigrants who lack the communications skills and the job security to take action and would probably be fired if they did. We all deserve a safe workplace.

This was my second close call of the week, too.

Earlier, I leaned against a handrail that I have leaned against probably a hundred times before, only this time it was loose. I caught myself by placing my hand on one of the 4 counter-rotating calender drive shafts (500 hp @ 40 rpm) about 6 inches from the open portion of the universal joint which is plenty large enough for my whole arm to have gone into. No injury resulted, but it was close enough to make me ask for disiplinary action against the mechanic who left it loose. Had my hand gone into the universal, the best outcome would have been a lost hand or arm.

Sorry to have gone on so long, but these were some very stark reminders of the dangers involved in the work we do. Never take the integrity of any type of guard for granted and never assume that your clients or superiors would not send you into danger. They may not intend to, but ultimately it is your own responsibility to watch your own ass. Please learn from my mistakes as I am very lucky to be writing aobut them.

Good Luck and Watch out,

Glad to hear you're OK. You have to make the call. I have standing orders to my people; approach the area with caution, observe for anything that might be wrong and only proceed if safe to do so - if you can't get the data, move on after taking notes. If it's too bad then come get me for an inspection. Do not do an unsafe act! Machines take back-seat to safety and people. We have to be safe, no-matter-what, not do the job no-matter-what. I go on the roof, if it's too hot then everybody comes down, not just me. Sometimes we get caught-up in the job and put too much importance on machines and the bottom dollar of ROI to make PdM and ourselves look good. Ok, Ok I know I'd have to get a face-lift and a new identity to look good, but my Mom likes me.

quote:

Most of their employees are immigrants who lack the communications skills and the job security to take action and would probably be fired if they did

Definitely not the company I would walk into, not even for a visit.

I live in a tropical region and I know what 90% humidity is. Glad that you are ok, have not seen many heat strokes, except when in military service.

Well Dan
First things first.Glad you are all in one peice and still kickin.Temperature is a fuuny thing some can endure more than others.Yo seem to have hit your limit and are now more aware of the possible outcome of exposure to these temps.Iam glad you made the post and this info is here for all to read and soak up.The fact that the company what not aware or not of this condition should now be making plans to deal with problems.I would be asking the next time i went to see if they are prepared to assist if needed and to what extent they have gone to ensure this does not happen to anyone else.If they have not gonr forward with plans or operating procedures then i would not go into this part of the plant until they have made sure it is safe to do so.I know bottom line is dollars to a lot of people but you have to live to enjoy it.I agreee with the radio to keep a line open should this or anything else happen.What good is getting out of a situation only to not get the proper help.Keep your eyes open to every aspect of your surroundings more so in familiar places because we all get comfortable after while and are not as alert as when in a new place.Again good to see you still writing.Take care.

AS a consultant you go where they are cutting paychecks as a rule. And you run into everything from good safety programs to none at all. You can't depend on the company for JSP's (job safe practice formal documents) or for them to get it right anyway. Go with your rules - make your own; you own a company, make rules and set the minimum standard you'll work by. Tell them what you need and then what you want and expect. At best we are analyst, not safety engineers. But many years in various facilites make you a pretty good safety person I think. Like Danny, I sometimes try to put the job first - not a good thing.

http://www.osha.gov/dts/osta/otm/otm_iii/otm_iii_4.html
http://www.osha.gov/SLTC/emergencypreparedness/guides/heat.html

Here are links to two articles of relevance.

Danny,

You made a big risk to go for checking the vibration reading for the two fans in that unsafe condition!! 110 degree c is too much for a human to withstand. Thank God, U survive!!

I think itz better for you to purchase a key-chain thermometer and always keep it with you.

Have a nice time!!

Hi guys,
The attached file contain the "General Heat Stress Index" which may be useful.

Have a nice day!!

Danny - that is a sobering reminder about some of the dangers we can be exposed to. Thanks for sharing.

Another in a string of near misses for me:

Walking a route at a chemical plant, I walked down the short flight of stairs into a concrete well around several large tanks to get readings on a pump. Turning the corner, I was met full-face with a high pressure sprayer from about 10 feet away.

I was fortunate in several ways. It was not hot water or steam, no chemicals and it hit me from far enough away that the water had lost it's momentum and was no longer at the 3000 psi that the sprayer was capable of. The operator was quick to release the trigger, so I didn't get too wet, although it did help with the original topic of discussion here-heat.

I asked him why he hadn't cordonned the steps off to ensure no traffic in his work area and he said that no had told him to. Common sense is apparently not enough to cause this guy to make the investment of a couple of dollars in caution tape to protect not only other workers, but his insurance rates (contractor).

Even worse, when I reported it to the maintenance manager, his response was that I have to watch my ass out there. I realize that and do watch my ass, but I cannot protect myself from unseen and unidentified dangers. Apparently there is no protocol in place in this plant for the use of high pressure sprayers in traffic areas, but there should be and simple common sense would seem to dictate cordonning the area in the absence of a protocol.