5:23 wow! Look at the detail and accuracy on that white railroad tank car! I'm a model railroader and I'm telling you they've captured everything, the air hoses, the grab iron ladder rungs, the curvature of the coupler lift bar, the air brake reservoir cylinder. I can't believe they can achieve this level of detail for a brief background object!
These animations are used in the investigation so they HAVE to get every last detail, in another video they said that they even have to get even the smallest details like how a chain on a valve was hanging, or what direction a padlock was facing.
This incident was quite complex, but the operators did better that 95% of the other CSB videos: they identified the problem, and accumulating issues, and tried to resolve them. It only took a few mistakes for this accident to happen.
... no, they did not do well at all. MeSH has boiling point of 5gradC... therefore it was certain, that a significant part of the MeSH will evaporate during the "defrosting" procedure - and the operators knew, that the only place for it to escape was the vent system - which obviously (from how the rest of the story unfolds) vents to atmosphere - not to a scrubber or a flare! Moreover, everybody involved was incredibly lucky, that this all happened in winter. If it had happened during the summer, when the temperature of the process water was much higher, the water, that entered the piping in the first place would not form the hydrate, but flow into the storage tank, where it would have evaporated significant part of the MeSH inventory. This would have had likely ruptured the storage tank, or the piping, leading to massive release of MeSH - due to its toxicity, this would have been an US version of bhopal...
It all began with incomplete isolation of the reactor. The next and deadly mistake was leaving a supply pump on even though they didn't want anything supplied (tell me how that could happen - i mean that's like leaving a foot on the accelerator while in park)
And again it was human error that caused the accident. The two brothers died needlessly because they ignored basic safety principles of not rushing into an unknown situation with out assessing the risk much like an attendant entering a confined space to rescue the worker inside instead of calling for help from trained responders.
@@chloralhydrate does that system vent to the atmosphere? if the feed line was connected to the vent system at all, the vent system must be designed to deal with the chemical in that feed line. the gas was released when they tried to drain liquid from the vent system, which the video says is standard procedure, but it's also implied that liquid shouldn't be in the vent system at all. if the issue of liquid in the vent system was dealt with before the situation with the blockages, they would have noticed "hey there's liquid in our vent system, where did that come from?" rather than just going to drain it
Methylmercaptan is the stinky chemical found in lots of stuff, from skunk secretions to rotting organic matter. It's typically mixed with natural gas as an odourant for easy detection of leaks giving that characteristic "pungeant gas" smell Makes it all the more tragic that 4 people died suffocating on it though, what a terrible way to go
As someone who was nocturnal for thirty years, I beg to differ, but I understand what you mean. Companies forcing diurnal people to work at night is always a disaster waiting to happen.
This one made me grateful that I'm a programmer - I essentially make mistakes like this all the time due to the complexity of the systems I work on, yet there is often very little real-world consequence other than maybe a disgruntled user. I have empathy for the engineers and technicians who worked on this, esp in regards to their mistake in keeping that valve open. It seems in this case there wasn't really a disregard to safety so much as an engineering mistake.
Safety was disregarded multiple times, I cringed super hard at least 5 different times. The biggest one was the poorly designed vent system which they didn’t fix they just lived with and ignored alarms in. The other big cringe was closing the valve to the reactor and then walking off when they almost had the blockage cleared
software engineer - if you run some production online service then you know how having a system downtime is like being in active warzone repairing a broken down tank under artillery shelling. not to mention having a critical security hole found in your supply chain somewhere
I had a friend working there as a technical staff member. After the accident they began work on corrective actions but DuPont decided to shut it down. They came into work one day and were laid off with basically no warning, but hey, economics always rule. A few things not really mentioned in this video was fatigue and pressure from leaders to get the unit up and making pounds. It is very easy to lose situational awareness when many things are not going as planned. Add in fatigue, which is a major factor affecting shift workers. One question that should have been raised is what was the composition of the fluids that were routinely drained from the vent header prior to this tragedy. Did it have a history of having methyl mercaptan in it? If not, the operators could have become conditioned to not expecting that concentration of the chemical.
yep agree, seen it to often, targets, bonuses, promotion, and goodie too shoes bum lickers. Its all rush rush rush, pay less less less. Cut corners these days is like using this shavings as resources are none. Chemical factories that do not have remote controlled shut of valves these days and sealled hazmat areas/room for escape and panic buttons, no wonder these branded companies make so much money ! Shift changes, no one goes home until the emergency is cleared and the safety team say so. Communication and resources will get lost if not, Commumication is the major factor in accidents. 2nd is resources. 3rd is the company saving money on safety aspects, (cutting corners) 4th human error 5th computer programed wrong by a human,
Re: things not really mentioned in this video was fatigue and pressure from leaders to get the unit up Yeah, and that's the part of this "investigation" that doesn't get mentioned in any of these otherwise excellent videos. If fatigue and overwork were factors, then the executives with the huge stock options should go to jail.
working through a shift change instead of leaving it the next day for the same team to finish the job seems to be a re-occurring human factor in these accidents. These companies never want to wait a day.
isn't that the issue almost always either a closed valve leads to a weaker component breaking open, a closed valve leads to contents redirecting to unintended locations, or valves are left open in error
I wanna be the guy who goes into the toxic clouds past dead people and turns off the thingy. I bet that guy gets paid and I'm already emotionally fucked up from home invasion gone wrong type shit so I can walk past some dead people in an HEV suit and turn things off if I get dental coverage. Like 90% of it is just driving quick to wherever at some unlikely time. It just sounds like okay work.
At first when I saw this new form of video it was a bit more of a departure from their normal presentation, I didn't really care for it, but now I really dig it. I love these videos, it's like a little mystery video, not to mention the information and animation are very detailed and clear to understand.
I'm a retired industrial union painter, and I never did like working inside chemical companies. I worked in several plant's in Louisville KY area called Rubbertown. It's amazing a very bad accident never happened there. Rusty old pipes, and storage tanks. All of them also had loading and unloading facilities on the Ohio River.
The narrator needs to be hired for Forensic Files III.... his voice is so soothing! And the animators..... wow, yall are getting reeeeeally good at this!
I really enjoy learning about safety in industrial facilities from CSB. The animations are amazing. It's awful the tragedies that have occurred, but I am thankful that we have organizations like the CSB to investigate what went wrong so others, like myself, can learn what to watch out for in our own facilities.
I love these videos because they have the natural consequence of raising workplace safety awareness. Remember folks, you always have the right to refuse unsafe work.
States of flux are almost always the most dangerous ones in any process unit. Coming up, or going down are fraught with potential problems you just dont deal with daily. Its really a shame this is the way lessons are often learned.
From what I have read methomyl is produced by producing first an intermediate oxime, usually methylthiomethyl oxime, and then reacting it with methyl isocyanate. I believe the production of the intermediate using methyl mercaptan is unique to DuPont.
PPE is the last line of defense. Before that are hazard elimination, hazard substitution, engineering controls, and administrative controls. Workers should never have been required to vent pipes connected to process lines into the building, especially with acutely toxic chemicals in use.
My goodness. That was a complicated set of failures. I appreciate the CSB for making a 3D model that seemed quite accurate of the processing units and the animations they made to show the flow of Methyl Mercaptan and Hot Water. This is good to keep in mind, I think a lesson could be learned to evaluate where the flow will relieve too if the liquid expands and flows from the pipe into the vent header. And another lesson would be to have proper drain points or knock out pots, so liquid does not build up in the vent header.
Methylmercaptane is also used for giving natural gas the gas odor most everyone is familiar with. I got a whiff of the stuff by just standing next to a tank of it in a plant, and could almost taste it at the thought for several weeks later.
That’s the characteristic that butyl mercaptan has they want considering it’s detectable in parts per trillion by humans. Incidentally it also forms in bottled beer when its packed in green or clear bottles uv light breaks down amino acids in the hops they use to flavor beer creating an off flavor commonly know as skunking. It’s also the active ingredient in skunk spray as well.
Shift change? Oh, hell no. I wouldn’t be able to leave my job if there was a critical chemical PROBLEM that complex. No pay? Fine. I’m not risking my coworkers or the public.
The problem was complex in hindsight, but their misunderstanding made it seem very simple. You would have briefed the new supervisor and gone home to your family. You would have no reason to believe anyone was at risk. Hindsight is 20/20.
Oh Captain, Mercaptan! Ross would be proud - this is the stuff that makes natural gas smell bad. Tell someone that on a date and they'll think you're a huge nerd.
This is why you don't understaff your Environmental health & safety department. These greedy corporations don't want to spend the money to take the load off the shift supervisors' backs and let the EHS safety officers protect your staff and facility from accidents like this.
Have you been to a refinery? Perhaps if they maybe worked a weekend or possibly stayed onsite for more than 7 hours. Environmental is a job for small minded little hitlers.
I work in plants/refineries and Ive always hated shift change. I think any job started must be finished by the shift that started it. Meaning- No handing off of jobs. That would cut incidents in half. I was working around this DuPont the year this happened and I cant remember hearing about this...
Lots of air accidents have happened because one shift didn’t tell the next shift what work had and hadn’t been done. Excellent point in many industries.
How is it not standard practice for employees to carry respirator or emergency SCBA equipment ON THEIR PERSON when working with highly toxic materials? It is just common sense, especially in confined spaces and with such huge quantities or material.
It was never thought possible for it to be in that building. Literally tons of it got injected into the vent system, turning the whole place into a gas chamber. Emergency SCBA was available. The two brothers looked like they had donned five-minute escape hoods, but died anyway.
These animations are so good. Especially for being a bit of an older video, makes me more intrigued. Thanks RU-vid, I’ll never use this information but it’s interesting as fuck.
I have learned so much about the the processes needed to make stuff from this channel......I love learning how stuff is made..then I also like to know what happens when you FUBAR a process that can kill people My top 2 Subscriptions on You-Tube are "How it's made" and "USCSB"
I'm a little surprised a plant working with poisonous and volatile compounds wouldn't have either 1) SCBA gear stored in multiple easy-to-reach locations, for workers to be able to close valves or shut down equipment in the event of an accidental release, or 2) equip teams with smaller breathing masks, with a short-term air supply, intended for immediate evacuation while a better-equipped damage control team is en route.
Not opening valve--> no water in feedline--> no hydrate-->no need of heating--> no thermal expansion---> No overpressure of feedline--> no need of venting---> no methylmercaptane in vent system---> no release of methylmercaptane
If it's a mercaptan the smell from working around this factory would be horrible. I'm surprised they could find anyone to work there. Good presentation. And DuPont is known for having a serious process safety management program.
I like these. They make me feel smart for knowing not to mix things and having a basic understanding o fchemistry (I'm not saying these professionals don't know that btw)
It still shocks me that people just walk away from a currently running, ad-hoc chemical process "hey let's go take a coffee break, this doesn't need eyes on it at all times". As always a very well done video, and a sad one.
what i dont get is , it is like only 25 ppm mercaptan is ok to odor the product, what kind of flows they are working with and placing such drains in an enclosure doesnt really makes sense to me
I used to work in the oil and gas processing plants in the Intermountain West and then within chemical plants on the upper Gulf Coast of Texas. I saw things that were unsafe but I was young and didn't think much of it. I know now I probably should've worked every shift in an SCBA...lol. I got lucky, many do not.
I was waiting for the voice to go all "but unbeknownst to the herd of wildebeasts, there is danger lurking underneath the deceptively calm surface of the pool. A vacuum inside this Nile crocodile's stomach has been steadily building up over the last twenty-four hours..."
Several reasons- Usually for cleaning/purging of equipment. If just the feed tank needed to be cleared you wouldn't purge through the reactor, you would purge it to the vent header, but only if it were liquid free. These kind of connections are absolutely necessary for maintenance to be performed, but what happened here was during troubleshooting which is a much more difficult situation to deal with.
