Lethal Service - Carcinogen 5

[Clareok]

We have a new vesssel to design. The vessel Contents are deemed to be "highly carcinogenic, which have the ability to penetrate the skn causing serious harm".

Does my vessel fall under UW-2?

Tks
J

 

[StoneCold]

Why don't you state what the chemical is?

 

[SnTMan]

What's your risk tolerance?

 

[EdStainless]

Usually LS is used for things that cause immediate harm.
Things that kill you slowly are often dealt with through double containment and such.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[Tomtation]

Paragraph UW-2 states "...it shall be the responsibility of the user and/or his designated agent to determine if it is lethal..." There you have it, your customer specifies whether it is lethal service and you must design it accordingly.

 

[fegenbush]

"highly carcinogenic, which have the ability to penetrate the skn causing serious harm"

Vinyl Chloride?

That's the first thought that comes to my mind when the term "highly carcinogenic" is mentioned.

 

[MJCronin]

AAaaaaggggHHHHHHH....!!!!!

Again and again we begin another magical dance....trying to answer the eternal question....do I have "leathal service" as defined by ASME.

I have maintained for many years that the ASME methods are an unnecessary and bizarre Kabuki dance of subjectivity that the plant owner is supposed to perform. Invariably, he will ask the consulting engineer what to do..

A list of certain lethal chemical should be developed by the EPA for everryone's benefit.

http://www.eng-tips.com/viewthread.cfm?qid=198830

My opinion only......

 

[fegenbush]

I think the government can be left out of it. This is something that needs to be clarified between the purchaser and the engineer. Companies need to be informed as to the cost difference between the options and let them and their underwriter decide if it is worth the additional cost.

If the EPA gets involved, there will be problems with concentration. "2 ppm, this vessel should have been lethal service rated." When, in reality, 2ppm may exist in river water.

 

[Duwe6]

If 2 breaths of the chemical won't kill the average person, I don't list the vessel as Lethal Service.

Benzene is a known carcinogen, and we keep it in 1-gallon tin cans. Cancinogen does not equal Lethal Service.

 

[MJCronin]

Fegenbush,

You miss the point....... a complex guideline that relies on research and subjectivity IS NO GUIDELINE !!!!

The ASME VIII guideline to determine what is lethal is subjective and way, way too complicated !!! (My opinion)

Can we simply agree that, for example, ASME vessels containing deadly 100% Phosgene Gas are "lethal service" regarding ASME vessel design ...????

How about 20 or 30 of the other major "bad boys" ????

Can the EPA simply make a list of the really,really bad, commercially traded chemicals and, by fiat, proclaim these as "lethal chemicals" ????? If not, why not ?

The poor contract vessel design engineer and the 23 year old newbie engineer should not be doing a research project everytime
a design spec is written.

My opinion only

 

[moltenmetal]

OK MJCronin: what about chlorine? Is chlorine uniformly considered lethal service? It might be for the storage bullets, I don't know about that as they're DOT certified devices unless I'm mistaken. But I've seen lots of chlorine piping systems that were not defined as lethal service under B31.3.

 

[MJCronin]

You have made my point, moltenmetal...... this "leathal service" determination is subjective..

I would include chlorine and phosgene gas in a list of chemicals where ASME designed vessels (over a certain volume) must be designed to leathal service requirements.

Why can't this be made more simple ????

The EPA already has developed a list of the bad actors (SARA EPCRA Chemical reporting List) complete with CAS numbers.

http://www.ehs.indiana.edu/sara/tpq.html

Why can't we simply take the worst of the worst (say, any chemical with a reportable quantity of 10 lbs or less) and, BY FIAT, proclaim these as requiring an ASME "leathal service" design for any vessel ?

BTW, ASME B31.3 has a category M for certain chemicals.... the same approach could be used for piping system designation

Other approaches are possible.....but the system should be made simpler.

I wonder how this question is answered in othe parts of the world ?

My opinion only

This wou

 

[vpl]

What's interesting to me is that the OP has been logging into the site everyday, but has never bothered answering the original questions or posting any additional information.

On the side topic of whether "somebody" should define what constitutes "lethal service," I'm not in favor of the government dictating what is, or is not, lethal service. I've seen too many cases where one person, usually not on a technical level, rams through something that doesn't make sense and everyone else ends up paying for it.

Patricia Lougheed

******

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[MJCronin]

vpl....

I don't like the govenment either.....

However, we still have to have SOMEONE go through a determination about if a particular chemical must be contained in a vessel designed for ASME "leathal service".

The 23 year old client newbie assigns this task to the vessel designer in the purchase specification. (I have seen this many times)

The vessel designer finds that he must now become a deadly chemical expert.

The MBA/PMP wants to know when it will be done.....

vpl, what other suggestions do you have to improve this problem ?

 

[Clareok]

I’m that 23 year old apprentice engineer that hasn’t bothered with a comment, simply because I can’t.. sorry for bothering you..
Seems nobody has the definitive answer... Maybe ASME might sort it out in the next addition.

Thanks for all the post thou.

 

[stanweld]

The Owner/User or its designated agent has the responsibility for determining Lethal service. The Owner/User has primary liability for illness/death of any individual exposed th the discharge of the Lethal substance. If one is the Owner/User's designated agent and believe the service to be Lethal to protect oneself from liability, so state it. If the Owner/User over rules the decision of its designated agent, the Owner/User assumes full liability.

 

[SnTMan]

Agree w/ stanweld, if in doubt, so designate it. After all, we are only talking about a moderate increase in cost of the vessel, as opposed to assuming an unknown liability.

Regards,

Mike

 

[Duwe6]

SnTMan has the 'kernel' of the question. This needs to be handled as a Risk Based Design. Meaning that the owner's insurance carrier needs to be intimately involved with the Cost vs. Risk vs. Consequences decision.

When you put some actual numbers into this equation, you will probably find that the fairly substantial increase in cost to go to the extra-high reliability welded joints of Lethal Service is justified when balanced by the lifespan of the vessel and the $$ millions, if not $$ billions if a release gets to any unprotected people.

The only reason Union Carbide survived Bophal, India was that the cost of life was in the $1,000's there, not $$millions.

 

[vpl]

MJC,

I agree with the already posted solutions about (1) bouncing it back to the ultimate client or (2) designing conservatively.
For a permanent solution, in my industry, this would be handled through either an industry group or the technical society.

I can't say I don't like the government -- after all, I've worked for the US government my entire working career. There are a lot of very good, very sharp folks in my agency (not necessarily including me :-D.) Maybe I can just say that I've observed the mechanics behind how some regulations get written and I fear that having "the government" come up with a list would end up with every nitrogen bottle having to be designed for lethal service.

Patricia Lougheed

******

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[Duwe6]

Amen to the government almost certainly going overboard. Rules need to be written by the folks that live & die by them. That's where the entire ASME Code came from. Good practices that ACTUALLY Work in the field. Uncle Sam always leaves out the feedback loop. There is never any feedback that they are Mandated to consider. They, as lawyers, CPA's and baby engineers write it, and now it has Force of Law. You cannot run any process without feedback that is acted upon.

vpl, easy on the self-deprication. "It ain't arrogance if you are really that good".

And ALL Nuke-Pukes are only as good as their last 1 or 2 mistakes. There's a LOT of horsepower on this blog, and I havn't seen anybody find an "oops" with your name on it.