Ammonia - Is it Lethal?

YES!!!

Depending on many factors, but yes.

It is an irritant and is also lethal.

Ammonia is lethal in Certain Doses.

See http://www.cdc.gov/niosh/idlh/7664417.HTML

Get something straight here- ammonia as used for cooling is ANHYDROUS ammonia (basically pure), not the aqueous ammonia solution commonly used for cleaning chemicals etc.

It's a gas under standard atmospheric conditions, and easily compresses to a liquid.

And it's lethal.

As many a dead farmer can tell you, ammonia is nasty lethal, and very quick.

Since you seem to wish to use ammonia as a coolant then 17 does apply and you are not to use the cooling jacket as designed. IF you had researched for the proper design specification for an ammonia filled cooling jacket system then you would not have an expensive piece of unsuitable hardware sitting there. To what standard is the rest of the system designed and built ? Did you research for a cooling jacket and THEN decide to use ammonia ? Think more, spend less and live longer.

In the USA, anhydrous ammonia has been stored in ASME section III, Div 1 vessels for many years.

There are thousands of these "bullet storage tanks all over the world. The design pressure (MAWP) commonly is 250 psig.

The point that you bring up is a good one and has been brought up many time in more responsible fora. It is not up to the newbie vessel designer to determine if a substance is "lethal". It is up to the user of the vessel.

Banu, is this the first vessel that you have designed or specified ?

Water is lethal too. The LD50 in humans is about 16gal. One can drown in much less.

16 gallons? That sounds like LD99.9999!

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I'm thinking at least 50% would die from consuming 1/4 of that in an hour.

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I doubt many people would survive being forced to consume 4 gallons in an hour....and drinking it would be far preferrable to inhaling or IV injection.

If you doubt the potential lethality of ammonia, this video should clear it up... . video

For the purposes of the pressure vessel code, ammonia is not defined as lethal. This may relate to the fact that there are permissible occupational exposure levels.

I agree with Tornado.

There is "lethal" in the commonly used sense and there is "lethal service" as vaguely defined by the ASME VIII code.... there is also the point made above that anything can become "lethal" in the right circumstances.

On other, more responsible for a (www.eng-tips) I have complained that the ASME criteria for "lethal service" is too vague, subjective and convoluted. Others disagree.

In the USA, anhydrous ammonia is not stored in vessels designed for the ASME-defined "lethal service"

There are discussions of this topic on: www.pveng.com and www.safteng.com

Nevermind...

(I linked same video as Truth before seeing is post)

Ammonia (gaseous) is very lethal. It has an IDLH, Immediately Dangerous to Life and Health, of 300ppm (20 min exposure without ill effects). It has a STEL, Short Term Exposure Limit, of 35 ppm for 15 minutes.

In can also be lethal in secondary ways-

http://www.washingtonpost.com/world/the_americas/3-dead-10-injured-when-construction-accident-ruptures-pipeline-carrying-ammonia-in-mexico/2013/08/20/7e715b2a-0a14-11e3-89fe-abb4a5067014_story.html

In its pure gaseous state it is also flammable although it is listed as non-flammable by a technicality. Despite what some literature says, it will burn at high concentrations.

Farmers are frequently KILLED by mishandling ammonia when used for a field fertilizer.

It is also very reactive with oxidizers. Some people continue to mix 5% liquid ammonia (household ammonia) with household bleach (5-10% Sodium hypochlorite, "Clorox") for "super cleaning solutions". The result is the production of Gaseous Chlorine, quite nasty stuff!

Lastly, use of ammonia as a jacket coolant requires a lot of refrigeration equipment plus the hazard of leaks still remains.

Good Luck, Old Salt

All good points.

. .

. . . . .One minor correction is needed: mixing household products containing ammonia with household bleach (solution of sodium hypochlorite) yields mostly chloramine and dichloramine as well as other very minor products; but generally not chlorine gas to any significant degree.

Those gasses are indeed nasty, so your advice was good even if t the reaction was a little off.

Very good points.

My general consensus, from a Haz Mat response approach, has been similar to the duck approach: if it looks like chlorine, smells like chlorine, tastes like chlorine and reacts like chlorine, get the victim out of the exposure area and onto oxygen. This holds true also for all the materials you have mentioned and many others like them.

Unfortunately, I have had to respond to many more of these incidents than I should have had to. Despite numerous cautions on the containers of bleach and ammonia people continue to mix them. This includes many who should have been smart enough to not do it.

Thanks for the clarification.

Good Luck, Old Salt

Lastly, use of ammonia as a jacket coolant requires a lot of refrigeration equipment plus the hazard of leaks still remains.

True. However that's not the point. The questioner did not ask regarding construction of large storage tanks, chemical reactors or tanker vehicles. Typical R717 refrigeration plants hold relatively small quantities of ammonia under ideal conditions. Leaks in refrigeration systems most often go unnoticed by neighbors outside the plant. For example, throughout Canada ammonia is extensively used as primary refrigerant for ice skating and hockey rinks in enclosed structures packed with skaters and spectators.

Conclusion: Cooling jackets in R717 refrigeration systems are not normally "Lethal Service" under the ASME code.

Zvi-

I respect your posting just as I hope you respect mine. Perhaps you were addressing a different part of the posting than I was. This sometimes happens, unfortunately a lot more times than you, me and others would like to admit.

Was I missing something, in reviewing the original posting? The author did not mention the size or configuration of the unit. He only stated that it is a cooling jacket. My reply was addressed towards cooling jackets in general since he didn't clarify it any further than that. Point was "Coolant is Ammonia. Is Ammonia a Lethal Substance?". My reply was: Ammonia (gaseous) is very lethal. It has an IDLH, Immediately Dangerous to Life and Health, of 300ppm (20 min exposure without ill effects). It has a STEL, Short Term Exposure Limit, of 35 ppm for 15 minutes. Although some may debate the effects of it, anything that is IDLH is something to be extremely careful with and appropriate cautions used in handling it or the equipment exposed to it.

R717 is the same as Anhydrous Ammonia no matter what you call it. http://www.airgas.com/documents/pdf/001003.pdf . CAS No.7664-41-7; UN 1005; Hazard Class 2.3 (poisonous gas); Health- toxic may be fatal is inhaled, ingested or absorbed through skin (ERG Guide 125, Gases Corrosive); Odor Threshold 17 ppm. NFPA 704, Fire 1, Health 3, Instability 1. Also originally made from the steam distillation of reindeer and deer horns.

In the late 80's a refrigeration plant operator died from his exposures to Ammonia at a large military base which shipped, among other things, frozen food to other locations. He thought he could fix the problem quickly without PPE. Obviously he didn't. That system held a large amount of Ammonia, much bigger than a relatively small quantity. The initial radius of evacuation was 500ft but increased soon after. Small leaks were filled from cylinders and large leaks were filled from a bulk truck. Also at one location where I worked, we used Anhydrous Ammonium as part of our processing and cleaning. It was treated with all respects due it, including lethal. This included MSDS's, vendor training, personal experiences, consultants and other authorities smarter than us. They all said it is extremely dangerous and easily becomes lethal. They also said "Don't take any risks".

A few weeks ago passed by a rink where a NHL team practices regularly. The refrigeration plant is separate from the rink areas. This avoids the potential exposure to ice users.

Any energy taken out of the ammonia for cooling must be returned to it by some means, usually mechanical. You must pay for what you get. (Carnot Cycle)

The basis for the applicable ASME codes is that it is up to the user to determine if a service is lethal.

In the majority of safe Ammonia processes/uses a conservative approach to safety is more likely to lead to no problems for the operating personnel, general population, environment and the equipment

Conclusion: Lastly, use of ammonia as a jacket coolant requires a lot of refrigeration equipment plus the hazard of leaks still remains.

Perhaps we are both correct but on different phases of it.

Good Luck, Old Salt

Old Salt,

I think we both agree that ammonia, even when used as a refrigerant, remains a toxic substance that should be used with care in properly designed and well-maintained installations. With your rich background in safety engineering, you could teach us ME's a lot about those hazards.

A cooling jacket, by definition, will contain a relatively small amount of ammonia at low temperature and pressure, mostly in a gaseous state. Therefore, I hesitated to regard this as "Lethal Service" under the ASME code, even while the entire refrigeration system may contain large amounts of ammonia. The bottom line will have to do with which kinds of welded joints are permitted and whether they require x-ray testing.

I mentioned ice skating rinks since thousands have been built over the years using ammonia as a refrigerant. You mentioned that you saw one where the refrigeration plant was separate from the rink areas but you didn't state what substance was used to freeze the ice in the rink.

Ice rinks typically use an under-floor grid of pipes laid on 4" centers to form a heat exchanger to freeze the water above the floor. In some rinks, pumps are used to circulate brine in the pipes. The brine acts as a secondary refrigerant, cooled in heat exchangers by ammonia from the main refrigeration plant. But in many installations a secondary refrigerant is not used. The ammonia itself is circulated in the under-floor pipe grid and produces ice above the floor through direct expansion cooling.

The direct expansion system is system of choice from many points of view: lowest first cost, low operating costs, most energy efficient, minimal maintenance required, long system life and 100% friendly to the environment. It has been used extensively in Canada in hundreds of installations. Ammonia DX is now used in outdoor rinks, but no longer permitted in enclosed buildings due to the potential exposure to the skaters and spectators. However, the existing rinks may remain in use. In France nearly one hundred ammonia DX skating rinks were built, over half the total for that country.

Evolution of Ice Rinks

Due to a need to conserve energy and because of environment concern, the use of ammonia, R717, as a refrigerant will increase in the years to come. When ammonia is used in large chillers for comfort air-conditioning in downtown Chicago, times are changing. Or, is this history repeating itself? Another rising star from the past is CO2 which is being used a refrigerant in super-market refrigerators and freezers. But that's another story.

Old Salt, we sure don't take lightly any horror stories involving ammonia. But our family car is far more lethal. Yet we take the wife and kids out for a drive in the country and we try to be as careful as we possibly can.

Your note about Chicago is an interesting development. I had heard before of ammonia used for air-conditioning in South African mines (I think secondarily via a chiller), though not yet in the U.S.
But one can do some pretty large plate/frame setups with a quite modest refrigerant charge. And the alternatives (older CFCs, newer HFCs, etc.) have their own safety concerns.

Tornado,

Here's a link to Chicago's downtown chillers: Thermal Chicago

Zvi

Thank you! That was indeed an interesting and well written article. I wish the designer(s) contractor(s) had been mentioned, though.

(For comparison, IIRC, the former World Trade Center had seven 5000-ton R-22 chillers in the basement.)

What does UW-2(a) actually say?

This should help

http://www.youtube.com/watch?v=KT-3WZ-23Ac

It's not the substance. It's the dose. The LD50 for Pu₂₃₈ is about 7e-9gm....

Nitrogen is lethal when pure. Air contains 78% Nitrogen!

Ammonia (R717) has been used in refrigeration systems for over 100 years. It has excellent thermodynamic properties leading to high energy efficiency. It's environmental friendly with a zero ozone depletion potential. However, it does differ from popular fluorocarbon refrigerants in that it's flammable, toxic and corrosive. Therefore its handling and use requires adequate safety measures.

ASME section UW-2(a) states: "When a vessel is to contain fluids of such a nature that a very small amount mixed or unmixed with air is dangerous to life when inhaled, it shall be the responsibility of the user and/or his designated agent to determine if it is lethal."

Ammonia has a IDLH value of 300 ppm, higher and safer than sulfur dioxide (100 ppm) which was once extensively used in domestic refrigerators. In a properly designed and maintained refrigeration system using R717, construction of heat exchangers must be given the same consideration as any other pressure vessel in the system, no more or less.

Where is Billie Sol Estes When you need him???

I have firsthand experiance on the toxicity. It is far less toxic than many might think. If the concentration is too low for you to see it you can tolerate it for hours. If it looks like fog you can still tolerate it for a few minutes without ill effect. I have experiance this level quite a few times. You will not be able to keep your eyes open for more than a few seconds at a time because they will start to sear and you can't breathe through your nose because it hurts too much. If it is as thick as light smoke you might be able to survive a few breaths but I doubt if your body will let you breathe heavy smoke any more than it will let you breath water. I am pretty sure that would be quickly lethal. I do not know how these correspond to ppm but what it looks like may be more valuable. I would be very wary of being caught in a corner with ammonia gas because you will quickly lose your sight and you could lose your way. Having your tissues eaten by ammonium hydroxide is not a nice way to die.

I worked at a plant that used Ammonia refrigeration. The men would not waist time getting masks in almost all cases. They chose to work in Ammonia fog to shut the process down than to find masks. Quick work stopped things from getting out of hand. What happened at Bhopal probably wouldn't happen at that plant. I never witnessed a major leak I am sure there would have been a point where everyone would run for it.

aDIYguy-

What is you opinion ? If the operators were able to shut down the process without masks, what would they do if they ran into an abnormal condition which required them to stay in the contaminated area longer? Since you have the first hand experience and know a lot more than I do about the process and products, what would be the potential hazards, remedial actions and results of these situations. Some that came to my mind are: valve inoperable, loss of cooling water, loss of heat, contamination of raw materials, loss of agitation either mechanical or electrical, valve sticking due to foreign material in the ball or gate portion, broken control handle, broken valve stem or handle, leakage through valve packing, leakage through a valve, leakage from a gauge, etc.

How would they handle these types of detrimental conditions where they were unprepared for the length of time required to shut down or repair some of these situations. You have the best type of knowledge, first hand. What would happen under these conditions?

Good Luck, Old Salt

Lots of questions there, but generally speaking the guys would evaluate the situation. If observably minor, such as a loose packing nut, they would probably tighten it right on the spot. If larger, or uncertain, they would probably leave for a moment and return with a gas mask, or possibly even SCBA. Other actions might include closing an upstream valve elsewhere to allow the leak area to pump out.

Tornado-

Yes, I know what they would do, but what has his experience shown for their operations?

We can write all the operating procedures, emergency procedures, emergency for emergency procedures for all operating personnel, etc. but what do they actually do in the case of the types of emergencies they have had?

War story- Operator was boiling out (cleaning) a reactor with water and steam was on the jacket. The split second that he opened the lid to see how it was progressing it boiled over. Scalding hot water was on his uniform! There was a safety shower approx. 3 feet from where he was standing. He ran to the locker room 200 ft. away and got under a shower. He was helicoptered to the best burn center in the state. He suffered 3rd deg burns to his face, body and legs and over 50% of his body.

All of the personnel, including the office staff, were trained on the operation of the safety showers, why to use them, and how to use them at least annually. In fact the trainer would stand under the shower, unexpectedly pull the ring and turn it on while he was under it to demonstrate.

Why did he not use the safety shower 3 feet away? Everything and his training said to use it but he didn't. He later stated "I forgot about it in all the excitement and my pain".

"Murphy's Law" appears unexpectedly in many operations, is the cause of many and can make things worse than they could have been. What is the poster's experience in what actually happens?

Just my thoughts on the post.

Good Luck, Old Salt

Free association may be better suited to psychotherapy. Your question is so open-ended that it admits of no reasonable reply.

Tornado-

I respect your right to express your opinion.

In this case my question was directed to obtaining more information concerning the variance between what was supposed to happen and what actually happened. This was addressed to the person who had actual experience with the cited process, the one most suited to give factual information concerning this. If the question is open-ended that is because I do not know what actually happened and would like to have him tell me and all of us with no limitations to what he can say. "Nothing" or all the way to "disaster".

My interest in this is because I worked in the chemical/processing fields for most of my career. During that time I had either direct or indirect responsibilities for Environmental, Health and Safety. Areas that you either gave information voluntary or it was gotten from you with a subpoena.

As for the concept of "free association" I see no association between the previous question and the fundamentals or derivatives of the work by Freud, Jung, Ferenczi, Adam Phillips or others.

The "War Story" mentioned in the last post is a clear example of the difference between what was planned to happen and what actually happened. One purpose of a Haz Op is to identify what should happen, what could actually happen and what can be done to prevent any adverse actions or reactions.

For another example, have you every heard of the newspaper headlines that stated "DEWEY WINS, TRUMAN LOSES"?

Good Luck, Old Salt

aDIYguy-

What is you opinion ? If the operators were able to shut down the process without masks, what would they do if they ran into an abnormal condition which required them to stay in the contaminated area longer? Since you have the first hand experience and know a lot more than I do about the process and products, what would be the potential hazards, remedial actions and results of these situations. Some that came to my mind are: valve inoperable, loss of cooling water, loss of heat, contamination of raw materials, loss of agitation either mechanical or electrical, valve sticking due to foreign material in the ball or gate portion, broken control handle, broken valve stem or handle, leakage through valve packing, leakage through a valve, leakage from a gauge, etc.

How would they handle these types of detrimental conditions where they were unprepared for the length of time required to shut down or repair some of these situations. You have the best type of knowledge, first hand. What would happen under these conditions?

Good Luck, Old Salt

What is you opinion ? If the operators were able to shut down the process without masks, what would they do if they ran into an abnormal condition which required them to stay in the contaminated area longer? Since you have the first hand experience and know a lot more than I do about the process and products, what would be the potential hazards, remedial actions and results of these situations. Some that came to my mind are: valve inoperable, loss of cooling water, loss of heat, contamination of raw materials, loss of agitation either mechanical or electrical, valve sticking due to foreign material in the ball or gate portion, broken control handle, broken valve stem or handle, leakage through valve packing, leakage through a valve, leakage from a gauge, etc.

Where to begin…

The blue collars were sensable and competent they would do what was smart and they had pleanty of practice.

I do not claim to be an expert but I have had personal experience with ammonia fumes. I know from experience you can survive 'lethal levels' by taking slow shallow breaths through your mouth. I figure if you took deep breaths instead of shallow slow breaths that level is probably lethal. I also wanted to make it clear if you can see the vapor, it is caustic and a big danger is that you can be blinded then dissorented. As a young and foolish manager, I did most of the most dangerous tasks because I work well under pressure had great reflexes and motor skills and never panicked. The blue color workers in alcohol distillation and some areas of maintenance were far smarter than upper management. They were remnants of when the plant was in its glory. They were exposed to way too many dangerous situations and became experts at disaster recovery. In alcohol distillation, we never made the same big mistake twice but in the rest of the plant never learned from any mistake. That is why we were the last department to shut down. In the rest of the plant, we had geniuses trying to keep processes designed by morons running as best they could.

This experience is only due to that it was before OSHA and that the company was run by complete incompetents. In the 50s the company had been extremely well run but fell into ruin after the founder died that the company was taken over by his son in law. I was part of an experiment where they hired kids out of college to be groomed for dept heads. The young hires were all very capable and had been hired by the old timers that had not left after the takeover.

The plant was an 80-acre plant and in the top 10 largest chemical plants in the US. I am not an engineer but a biologist. I was hired to train in the fermentation plant. I was transferred to alcohol distillation when both the dept head and his assistant left for better work. I will note I quickly discovered engineering is more about genes than education. I can from a very long line of engineers my generation was the first generation who were not all engineers since the 1700s. When I would ask an engineer how something worked it was obvious to me the explanation was wrong. Between cracking books and observations, I was able to figure out what was really going on. The reality was none of the processes were 100% a certain process as the engineers believed. They were 80-90% one process with bits of other processes thrown in. Once you understood what was truly going on the process were predictable. The engineers and management thought I was a crazy kid. The only person that took me seriously was the old dept head who came out of retirement to train me. He dropped out of school in the 5th grade and was as smart as a whip even though he was over 70 years old. He mentored me in management and seat of the pants engineering. What came out of his mouth was amazing.

In my training for a department assistant I needed to spend 2 months in each of the 24/7 factories in the distillation group. On the weekends we were on a rotation where someone came in on the weekend. We needed to have a basic understanding of all the plants in our group.

The ammonia was used at the acetic acid plant. The same idiots that 'helped' us at the alcohol distillation plant were screwing up the acetic acid plant. The coolant lines kept developing pin-hole leaks because they weren't engineered correctly. This concept was well beyond intuition. My tuition did tell me you should not be springing leaks every 10-15 days but I didn't know why. When I was eating with my father, I asked him if this should be happening and he asked me questions I couldn't answer. I knew what to look for and made a diagram of the piping when the next leak occurred. My dad told me the pipes were work-hardening the pipe needed to be much lighter gauge and the lengths of pipe had to be much longer to dissipates the flexing from the vibrations. The engineers laughed at the suggestion and continued to use heavier and heavier gauge pipe and we continued to sprout leaks every 10-15 days. My father was the top engineer in an international pharmaceutical company. He was the last word when hiring plant engineers anywhere in the world. That brings to mind a Chinese proverb wise men learn more from fools than fools do from wise men.

The safety equipment was state of the art of the 50s but this was the 70s. The masks had acid and activated charcoal filters. A few floors away there was a self-contained air unit but the air tank was so heavy it required a hand truck to move. The masks had low visibility, were hard to breathe through, and were not conveniently located. Had it been my department I would have tried to upgrade all the equipment and had better masks stored where the leaks occurred most. In alcohol distillation, our problem was steam leaks. There were areas that my have been as loud as 200db. I ordered ear protection and repaired 2-3 of the worst leaks when we would go down for repairs each year. Within a few years the noise level was half what it had been.

The men would take turns if need be. If there was a leak the rest of that plant quickly came to a point outside where they could spell the operator if need be. However, that was not necessary in my 2 months rotation.

aDIYguy-

Thank you very much for spending the time to enter that excellent information! It is just what I wanted to hear about. What was supposed to be done and what actually happened. You certainly are an expert in the unique area of processing that you ran in my book.

Your previous posting "keyed up my curiosity" because I started out somewhat like you do. I was the go-to guy because I could think and not rely on book learning. I was forced to become the primary responder because I could also think under stressful conditions and knew how to use much of the PPE. This includes once being the only one who could row a boat!

One of my assignments early on was being the Safety and Maintenance Manager of a site with about 100 people where we used Glacial Acetic Acid, metallic Mercury and Benzene. All nasty stuff! There was a "burp" of the Benzene recovery refrigeration unit on a building roof which put some Benzene on the roof. A manager, not me, went up and made some adjustments without putting a SCBA on. OSHA heard about it in about 20 minutes, due to a labor situation, and fined the company for it. Environmental agency also fined. Needless to say, the manager was fired two days later. If the operators had gone up they would have used a SCBA. What was supposed to happen didn't happen and all employees suffered due to close monitoring the agencies implemented.

As the new Safety Manager and Maintenance Manager (due to my areas of skills I was doing the work of two) I changed the safety program soon after. That plant, which usually had 3-6 lost time accidents a year, went a year, then 2 years, then three years and finally 10 years without a lost time accident. That was long after I had left that plant but the safety mindset was still there.

Again, I admire your skills and candor in your recollections of the "whole" operation of a chemical site. You are, without doubt, a very intelligent and knowledgeable person. It also appears that you have extensive "people" skills and especially a lot of applicable common sense. You certainly seem to have a very promising future in industry. Yes, the lineage of an engineer often is an advantage such as it has been with you. Not that you have nepotism connections, but the mindset that you grow up with because of those around you leads you to a "engineering" type thought process. My father was an Elect. Eng. who also loved to work with his hands. His favorite saying was "Think for 10 minutes and work for 5 minutes, not bust your b-lls for 30 minutes!?

Good Luck, Old Salt

To help determine if you as the user would coincided it lethal. WWW.CDC.gov/niosh/idlh/7664417.HTML Only you and your company as the user can determine if it is lethal under ASME. Hope this info is of use.

A website that might be helpful. WWW.pveng.com/ASME/ASMEComment/LethalService.php In it it give the definition under ASME viii-1 section uw-2 of a lethal substance. It also states that you as the user need to determine if ammonia meets the lethal requirements. It also gives a list of codes so you can meet the pressure vessel requirements. Hope this helps with answering your questions.

My dad's favorite saying was measure twice and cut once.

You sound like my kind of guy. I bet you made a great safety engineer. Doing thing safely is the right way. If the AA plant had the right equipment in the right place they would have used it. Breathing Ammonia is no fun. The safety engineer at the distillery was a joke. That is why people died every couple of years. We had little lost time accidents. I am sure we had none in my department in the 10 years I was there and we were often a busy place. The young managers were far more concerned with safety than he was. During my 10 years only one died and that of Ammonia poisoning. Two men were in a crawl space and a line ruptured. The lucky one was blown through a second story metal framed window. His body bent the metal frames. Even though his back and neck were broken, he lived.

They definitely needed OSHA but like so many monitoring agencies, they have gotten out of hand. I can say the exact same with the EPA. That was an outrageous for an exposure of 20 minutes in the open air. I can't comment about the labor relations. I was lucky in that the company was so stupid and slimy; I was a breath of fresh air for the blue collars. In the early days there were some slackers that probably hated my guts but either they left or turned over a new leaf.

About Benzene, we used it in a process as well. About once every .7 years we would have a benzene line break. Something would freeze up if I remember correctly. Everyone would get dizzy from the fumes. No one ever got leukemia and we had persons 30-40 years on the job. I did know of someone who died of leukemia from benzene exposure. He mopped the floors with benzene every day for about 2 years till it got him. All that said, I would not volunteer to sniff any today.

I have only contempt for management that the engineering staff. They were all losers. In my book a loser is so starved for success that he/she ignores any and all criticism. Winners seek out criticism before they start a project.

That was the most fun I ever had at a job. I think what you mean by common sense is really an 'engineering horse sense'. You get that from how your brain is wired. I bet the plant engineer had a higher IQ than I but he had no 'engineering horse sense'. I could tell him if and how something he was building was going to fail and he couldn't see it even when it was biting him on the ass. My wife can't read maps. Oh she can read them but she can't navigate by one. It is how her brain is wired. She has strengths I do not have and can't understand why I can't do things she can do effortlessly.

That was my last engineering job. That is OK working for a competent company would have been boring. My peer at the Acetic Acid plant got a job at a good company and hated his job because it was so boring.

I am now a software engineer. That is more interesting.

aDIYguy-

Thanks for the complement! Safety was one of my most liked and rewarding assignments. Unfortunately when you do a good job it isn't noticed, when you screw up everybody notices. You have to identify the achievements and advances you make on your own and give yourself the applicable "pat on the back". No one knows this better than another effective safety person. It is a lot easier when the people who you are "looking after" stand behind you , support you and want to be a member of the team. Bad managers and engineers, just as you said, are counterproductive and hurt the safety efforts. Easy to identify them, those who complain and those who ask how they can help their people more.

Having started my career with production before the Williams-Steger Act (OSHA) I have seen some of the worst safety conditions. Combine this with having to do numerous accident investigations including fatalities (fortunately at other plants and not mine) along the way you can see the importance of safety to the whole spectrum of life. All of them could have been avoided. There is no "accidental accident", just ask the victims family. I sometimes told supervisors and managers that if they wanted someone to reach the goals just get operations personnel started in safety. There is little that can be argued about it.

Although I am now retired, I can definitely say it was a loss for the chemical industry when you left. There are far too few people in it with an "'engineering horse sense" to accomplish what has to be done as well as keep people safe. I am sure your experiences from it will not doubt make the adaptation to software engineering easier and more productive for you in your endeavors ahead. I believe that not every good engineer was born with "engineering common sense". If they are smart enough to see what works for the system, other good engineers and themselves they can develop it by following the example of those who are successful at it.

Your postings have been extremely good and show your wide range of knowledge and skill. Keep it up; this forum needs more of it sometimes.

Keep in touch by CR4 "mail"!

Good Luck, Old Salt

A lot of great information and life stories given here. The simple "answer" for the poor OP's question is yes appendix 17 is applicable because its up to "him" not "us" to determine if it is very lethal under ASME. Several of the post have links to help the OP out.