Accident Investigation: a ‘Valero Case’


The discussion, which is examined in this essay, is based on the accident, which has happened on the November 5, 2005 due to which two workers of the ‘Matrix Service Industrial Contractors, Inc.’ died. The discussion examine what actions had to be taken by the investigation team, gives the description of the sequence of the events and the analysis of the given recommendations.

This information will help not only the companies mentioned below, but also other companies all over the world, to prevent the possibility of appearances of such accidents in future.

Description of the sequence of the events

Cleaning the Manway flange surface, Matrix pipefitter told the boilermakers to get the roll of duct tape, lying on the distribution tray. The boilermakers knew that it is prohibited to leave the tape inside the reactor according to the reactor cleanliness criteria. The retrieve of the tape requires a special training and equipment, which they didn’t have. They decided to use a long wire hook to retrieve the tape, not to delay their work,

Nobody saw how the first victim entered the reactor, but some witnesses saw him kneeling next to the studs, working with the wire. Trying to save the coworkers, the foreman hurriedly grabbed a ladder and immediately climbed down into the reactor. Observing all this process, the contract administrator called for a help on his radio and later the emergency siren was activated.

Emergency and Safety personnel arrived in several minutes, but they were unable to save them. Two victims were already motionless. According to the oxygen meter inserted through the Manway – the oxygen concentration was near zero. The victims were transported to the hospital where their death was pronounced.

Analysis of the accident

There are several issues to be discussed in this essay: what members of the investigation team are to be presented in it, what evidence had to be collected and who had to be interviewed. In addition, the characteristics of contributing causes and the Chemical Safety Board’s recommendations are to be provided.

It should be started with mentioning that every fatal accident on the manufactory adversely affects the image of it. If we talking about the factories and manufactories were production conditions are dangerous, the precautions should be increased not to let the fatal accidents happen.

But if such accidents happened, it is necessary to make the investigation properly, firstly, to understand the reasons why such danger arose, and, secondly, what measures are to be taken to prevent the opportunity of its duplication in future.

The investigation is to be objective, complete, realized independently and with considering all factors. For this reason, the issue who can be the members of the investigation team is significant.

Firstly, the members must be objective, as it once mentioned. That is why the investigation team should include the representatives of independent bodies, state or private. Secondly, such investigation team should also consist of representatives of company, factory or manufactory. These people will help to analyze the situation from the company perspective.

Comparison of both points of view will help to understand what really happened on the manufactory, which has to be blamed for this accident: the reasons why it happened, and what measures are to be taken to prevent such kind of accidents in future.

If the investigation team consists only of the representatives of independent bodies, the investigation can took a long period of time, and there can be more victims because of the company’s safety violations. On the other hand, if the investigation team consists only of the representatives of the company, such investigation is unlikely to be objective as the results of it will be based on the wishes of the company executives.

As for the evidences, the first thing that I was surprised of is the lack of video surveillance on the territory of the company. Reviewing the case study material, I didn’t find the information about the review of the video from the shift when the accident happened. Either such a huge and notable company doesn’t have a video surveillance (what is really surprising) or the investigation team didn’t consider the review of such evidence necessary (what is doubly surprising). This video would reduce the term, which was given to understand why the first victim was inside the vessel: was it his fault or the company’s negligence.

Secondly, as it is mentioned in the case study, the ‘Matrix’ was responsible for providing skilled craft people who are to undergo the safety training. Nevertheless, the workers probably believed that they could hold their breath and help the victim, just like they hold their breath, swimming underwater. However, inhaling water causes coughing, which is considered as a body’s breathing reflex. Regarding nitrogen, it providers no reflex, so it is unlikely that a person can hold the breath. Furthermore, inhaling nitrogen suppresses the brain’s breathing reflex response. The person, inhaled nitrogen, dies in several minutes.

In addition, the interviewed mentioned that they knew only about the hazard in the confined space and that at their training the possibility of oxygen deficient atmosphere to be present outside wasn’t mentioned about.

It was mentioned that the workers were unaware of this dangerous complications, however, according to their dangerous work, they have to know this. So, another investigation is to be made is the system of skilled workers preparation, which is conducted be the ‘Matrix’. This will help to understand why the information given during the training isn’t full enough.

As for the persons who are to be interviewed, I consider that the investigation team made its best: all workers who could see anything or know something were interviewed. As for me, I think that additional the Valero Emergency Response Specialists and Matrix safety personnel are to be interviewed. There is an opportunity that they noticed some details, which could be important for the investigation. The results of the autopsy also can be considered as evidence during the investigation.

Contributing causes

There are several contributing causes that can be emphasized. Firstly, it is insufficient training. As the evidences showed, the worker went inside the reactor himself. Moreover, instead of calling for a help the foreman mistakenly thought that he was able to save a worker.

Secondly, all the safe work procedures for using nitrogen were not fully implemented. The barricade and post warning signs were not used before the nitrogen purge was started. The boilermakers would have to work close to the open Manway, the place where the nitrogen is venting from the reactor making the unsafe oxygen levels. In addition, the nitrogen purge box was marked “N/A”, while it should be marked “Yes”.

All this together show the reasons why such kind of situation appeared and what measures had to be taken to prevent it in future.

Analysis of the Chemical Safety Board’s recommendations

The recommendations were given both to the ‘Valero Delaware City Refinery’ and the ‘Matrix Service Industrial Contractors, Inc.’.

The first recommendation is to conduct the refresher training for all refinery personnel and contractors. As we can see from everything mentioned above, it is very necessary to know about every danger at the factory. During these trainings the thing to be emphasized are (basing on the reviewed accident):

– The condition of the nitrogen purges status (yes/no/n.a.);

– The equipment condition control conducted by the executive workers;

– The permission for any actions must identify all possible hazards;

– The protective equipment is to be given to every worker;

– The barricades and access warnings are to be put in time and according to the action conditions.

These recommendations were given to the ‘Valero Delaware City Refinery’. The second part of recommendations was given to the ‘Matrix Service Industrial Contractors, Inc.’. They are based on the same thing – refreshing training, but they relate to the rescue procedures and the training of the well-prepared personnel from the beginning.

These recommendations are considered to be important for a future of the companies. Moreover, it can’t be said that there can’t be more recommendations. Unfortunately, another part of recommendations can be give only after correction of the made mistakes.

In conclusion, it can be said that, temporary, there is no need for additional corrective actions.


Every company has its problems, but the most important for every manufactory is the safety of the personnel. If it happens that some workers die, the company has to do its best to prevent such situation in future.

As for the case of the ‘Valero Refinery’, the company has to make the efforts to change the work of the staff as all appeared problems were caused the errors made by the workers of the company.