Episode 57 Lessons Learned From The Deadly Explosion In Pasadena, Texas

Lessons Learned From The Deadly Explosion In Pasadena, Texas

Nov. 7, 2023
The legacy of Mary Kay O'Connor, who was killed in this incident, has aided in promoting process safety and saving lives.

This episode discusses the 1989 Pasadena chemical plant explosion that claimed 23 lives. The incident led to the modernization of process safety measures in the U.S. Trish and Traci emphasize the importance of dedicated firewater systems, meticulous maintenance procedures, and strategies to combat complacency. They also explore the use of case studies and emphasize the positive legacy of Mary Kay O'Connor in promoting process safety. Subscribe to stay informed and visit chemicalprocessing.com for additional resources.


Welcome to Process Safety with Trish and Traci, the podcast that aims to share insights from past incidents to help avoid future events. This podcast and its transcript can be found at chemicalprocessing.com.

This episode is sponsored by Pepperl + Fuchs. Pepperl + Fuchs has been a leader in electrical explosion protection for decades, giving you the reassurance you need. Pepperl + Fuchs provides companies in the process industry worldwide with proven components, as well as customized and globally certified explosion protection solutions. The Pepperl + Fuchs product portfolio includes intrinsic safety barriers, remote I/O, purge and pressurization systems, electrical explosion protection enclosures, as well as HMI and mobile communication products for hazardous areas, just to name a few. Pepperl + Fuchs protects your plant, your processes, and your people.

I'm Traci Purdum, Editor-in-Chief of Chemical Processing, and as always, I'm joined by Trish Kieran, the director of the IChemE Safety Centre. Hey, Trish, how are you? What have you been working on?

Trish: Well, it's been a very busy time again. It usually always is a very busy time for me, isn't it? But I've been traveling around New Zealand more recently. I was over there for a big chemical engineering conference, which was fantastic. We talked about a lot of process safety-related aspects, so it's always great to meet people that are interested in process safety.

Traci: For us on the chemical processing side, we just named our Vaaler Award winners, the Biennial awards that we bestow on winners. They recognize products that promise to improve operations and economics of plants. So we've been working on that. That's going to be in our December issue. But looking forward to today's discussion, it's been 34 years since the fire and explosion at a chemical plant in Pasadena, Texas. On October 23rd, 1989, 23 workers lost their lives, and hundreds more were injured. It said that this incident helped modernize process safety and risk management programs in the United States. Can you explain a little bit about what happened that day?

Trish: Yeah, so first of all, let's just have a discussion about a little bit of history first. So this incident was in 1989, so that means it was about four years after, well, not quite four years, but almost four years after the Bhopal tragedy happened in India, which was the world's worst process safety incident that we'd ever seen where thousands of people were killed. Now, we were still reeling a lot from Bhopal at the time, when all of a sudden, this particular incident happened in Texas and it killed, as you said, 23 workers and up to 130 people were also injured in this particular explosion.

If we just think about what happened in the years following that incident as well. So before this Pasadena incident happened, the EPA had not issued its risk management requirements. The RMP didn't exist before this incident happened. OSHA had not issued PSA 1910 either. That was issued in 1992, and the EPA RMP was issued in 1990. It really was at the very beginning of the implementation of those different programs. So we've now, we're in a very different world now that we have those programs in place. They weren't there when this incident happened.

Now what actually happened in this incident, well, they'd actually been doing some maintenance activities on the plant, and they were doing some isolations to be able to disconnect some pipe work, and they'd done the isolation several days before and they left those isolations in place and they were actually locked out as well. So the valves were locked, the ball valves were closed, and something had happened in those couple of days that they hadn't had a chance to get in and do the work they were going to do. So the work was actually started a couple of days after the isolation.

Unbeknown to the workers sometime in the midst of that, the isolations had been removed. Now we still don't know who or why removed those isolations to my knowledge, but what ended up happening was a ball valve was inadvertently opened because the actuated air to it had been turned back on, and that opened the full bore of that ball valve to release the flammable substance that then ignited. So it was a propylene plant that then caused a massive gas cloud and explosion. We are really looking here at a lot of isolation issues, a lot of management of work issues, maintenance-type related issues about how we go about doing things.

And as I said, now, it's very different. It was interesting. They had isolated apparently, and they had locked out the valves, and they had disconnected the air, but someone had de-isolated it. We do have much more stringent lockout tagout processes now, no one could remove a lock that they didn't personally put on themselves anymore. So you can't go removing somebody else's lock without an enormous amount of effort that goes into ensuring that that person is physically no longer on site and physically no longer going to be doing any of that work, and a whole lot of safety protocols around that.

So it's interesting that we have seen lockout tagout improve quite substantially following on from this incident, not necessarily as a direct result, but certainly following on from it, and it's now very accepted standard everywhere to make sure that we do those appropriate isolations, lock them out, and that everybody has their own personal key to ensure their own safety. So I think there's a few different areas there that are really important to look at.

Traci: In the IChemE's Minute to Learn series, you talk about the areas of concern, and you've already mentioned a few of them, but I kind of want to dial back a little bit and talk about plant layout. What needed to be addressed then what have we learned, and what can facilities do today?

Trish: So I took this learning from the Marsh, “The 100 Largest Losses in the Hydrocarbon Industry” publication that they regularly put out. And one of the key aspects they talked about for this incident was that there was no dedicated firewater system installed. It was actually a shared system that also provided operational water. And when the incident happened, a couple of the pumps were actually taken out by the explosion, and the backup diesel fire pump ran out of diesel. It then failed to work as well.

So in this instance, not only did they have the explosion occur, they were then left with no means to fight that fire effectively, no means to respond to what was happening around them. And so, from that plant layout perspective, the need to always have a dedicated fire protection resource is absolutely critical. Fire-out resources should never be used for operational purposes. If you need additional cooling in your plant, then you need to put in additional cooling in your plant, not just turn on your fire pumps and use them for cooling purposes because you need to be sure that when you need those fire pumps in an emergency, they're going to work for you and they're going to be available for you. So I think that was a very important learning that did come out of this particular one as well.

Traci: Let's talk a little bit about the maintenance procedures and some of the lessons that can be applied today from the incident as well.

Trish: Yeah, the maintenance procedures, as I said, they were doing some routine shutdown activities. They had done the isolations days before and then gone back to do the job making the assumption that the isolations were all in place and fully adequate, and that is a really dangerous assumption that was made by the maintainers in that particular instance.

One of the processes that I had always done myself when I was authorizing any sort of high-risk work activity in facilities I've worked in is every shift before the work was started, a full walk of the isolation was done, and even if the work was going over two consecutive shifts when the second shift came on for that work to be reauthorized again, that maintenance activity, there was still a requirement to do a physical check of every isolation prior to the work starting just to make sure that someone somewhere hadn't removed something that they either thought they were doing the right thing, or in fact did by accident and shouldn't have done it all. I think it's unusual for there to be malicious action in this, so I don't count that as a realistic thing. It's either someone thought they were doing the right thing or just didn't realize what they were doing in most instances here.

You've got to make sure that if you're about to do some work if you are the maintainer and you're about to go and do some work and the preparation for that activity happened before you've had a chance to check it, you need to take a quick walkthrough and look for that isolation. You need to verify for yourself that you are adequately protected in what is going on, and if you're the person authorizing that work, you want to make sure that all of the isolations are still in place so that when you authorize people to do the work, you are not putting them in danger, you know for certain that all your isolations are actually in place there. Because in this particular instance, it was the inadvertent operation of a ball valve through an air-actuated system that opened up a full-bore release, something that really was very, very preventable and in fact had been isolated previously.

Traci: Now you're talking about preventable and there was no malicious intent obviously, but there can be complacency, and I think that sometimes that creeps in. How do you combat against that?

Trish: Yeah, great question. And complacency is one of the things we always have to be tackling, and it's around making sure that we have really good quality conversations in the workplace about the risks of the work we're about to do and make sure that people understand those risks and have those conversations in a valuable way. So it can be really easy as we're going in to do maintenance work and as we are doing shutdown work to do, oh, we have to do a toolbox talk every day, and we've got to say something, so look, let's all follow the procedures and let's all just be safe out there, okay. That's not helpful to anybody. That sort of approach to a toolbox talk is actually going to devalue safety, and it is going to generate complacency. What you really need to be doing is focusing on the specific hazards of the tasks that are going to be undertaken by the workgroup.

And the reason that is just so important is that our brains work in a range of different ways. They see a whole lot of subconscious patterns that occur all around us every day, and we don't even realize our brains are doing this, so we might've read an article on a particular topic and then all of a sudden you start hearing more and more about that topic. That topic has not necessarily got any more popular. It's just that your brain is now noticing it more because you've actually primed your brain to see that subconsciously. We can use that ability in our brains in a way to improve the safety of our maintenance activities when we do it.

So if we're going to talk about doing a particular task and it's going to involve dismantling of a specific piece of equipment, then we need to talk about the specific hazards that we've got. What is the product in there? How have we isolated it? How have we tested that that isolation is positive? How are we going to do that task in quite specific detail and what can go wrong in each step? If we have that conversation before we start the task then as we actually go through doing that task, our brains will be looking for signs that something's about to go wrong, and we'll give you that, oh, I've got a bit of an uncomfortable feeling. I'm not quite sure right now, I've got that gut feeling something's about to happen. We start to get these warning signals, these little weak signals that happen.

And so priming our brains to find these things is a great way to fight against complacency, but it takes commitment to do. It takes a willingness to sit down and have a conversation or stand at the job site and have a conversation about the actual steps. So we need people to realize what can go wrong? What are the consequences if I get this task wrong, is it going to hurt or kill me? Is it going to hurt or kill my workmate or someone else? Make sure people really understand the consequence because when they get the consequence and what the personal impact to them on that consequence is, they're more likely to be more interested in preventing that consequence happening.

Traci: This sounds like a perfect place to bring up or show video or showcase studies of what happens. Real case studies of, we're talking about these incidents in the past that have killed people, is bringing unease to the workforce and making them realize that you're not there to reassure them. You're there to make sure that they can walk away. Is that truly an appropriate place to show a video of some horrific incidents?

Trish: Yes and no. There's no clear-cut answer to that question, unfortunately, because everybody's different in how they interpret those sorts of things. I am typically very careful about using the shock horror images or video myself, and that's because I've actually witnessed some behavior when you do use it, and I have used it in the past, there's a cohort of people that it actually really works very well on without doubt. It works well. It hammers a message home, and it really burns it into their psyche that they're not going to do that, and that's great for that group of people. There are other people that it distresses, and when they're in a state of distress, you're not actually open to learning, so it emotionally distresses them. They just don't get that learning because they are physically and emotionally upset. And then there's another group of people who actually just completely disengage and don't even look.

You do need to be very, very careful about using those tactics because without doubt, there's a group it's going to work for, but there's also a couple of groups it's not going to work for where you need to take a different approach. Now, it's not pretending that no one gets hurt and everything's fine and everyone goes home safe. It's actually about talking about it in a different way, talking about what good looks like as opposed to what bad looks like so that people know what they need to strive to. This is how we're going to do this job because this will work this way. Videos of it going well, videos of doing this task and how it all works can be quite helpful to show those as well. So it's about balancing out the messages to make sure you're getting as many people engaged as possible, because without doubt, there are some people that just really thrive on seeing the gore. A lot of people don't, and we need to not forget them in the journey too, because they're just as important as the people that that's a response for.

Traci: Trish, do you have anything you want to add on this subject?

Trish: Just one last comment. This is actually a really interesting incident. So for those of you that don't realize, this was actually the incident where Mary Kay O'Connor died as a result of this incident, and if that name is familiar to you, that's because the Mary Kay O'Connor Process Safety Center was named after her after a very generous donation from her husband to start the center to make safety second nature for people so that these sorts of incidents don't happen again and kill other people, and he never wanted anybody else to go through what he went through in losing his wife in that instance. So that was Michael O'Connor, and sadly, he passed away recently, too. And I just think it's important that we actually do recognize that not only the legacy that came out of this incident was the EPA RMP and PSM 1910 in the US, but also the Mary Kay O'Connor Process Safety Center came out of this incident. I think that's a really honorable legacy for Mary Kay O'Connor following this particular event that happened all those years ago.

Traci: Absolutely. Such great work coming out of the center there. Thank you for bringing that up and reminding us of that. Unfortunate events happen all over the world, and we will be here to discuss and learn from them. Subscribe to this free podcast so you can stay on top of best practices. You can also visit us chemicalprocessing.com for more tools and resources aimed at helping you run efficient and safe facilities. On behalf of Trish, I'm Traci, and this is Process Safety with Trish and Traci.

Trish: Stay safe.

About the Author

Traci Purdum | Editor-in-Chief

Traci Purdum, an award-winning business journalist with extensive experience covering manufacturing and management issues, is a graduate of the Kent State University School of Journalism and Mass Communication, Kent, Ohio, and an alumnus of the Wharton Seminar for Business Journalists, Wharton School of Business, University of Pennsylvania, Philadelphia.

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