Back to TechNotes Library Page Gossman Consulting, Inc.

GCI TECH NOTES©


Volume 8, Number 1           A Gossman Consulting, Inc. Publication        January 2003


Catastrophic Accidents

Caused by Multiple Failures of Elements Within a Safety Management System

by

Dave Constans, Gossman Consulting, Inc.

There have been some rather spectacular catastrophic accidents at hazardous waste management facilities during the last few years. The explosion of a rail car at a hazardous waste fuels facility near Logansport, Indiana in February of 1999 probably being the most spectacular.  Rarely are such incidents the result of a single event. While a specific event does immediately precede such a catastrophic accident, this event alone will not in-and-of-itself cause the accident to happen.

An examination of the multiple elements needed to result in a fire is an example of this. To have a fire, whether it is to warm your house or to burn a forest, requires three things; fuel, oxygen and an ignition source. Remove any one of them and a fire cannot occur. This same principle may be applied to devising safety systems for industrial facilities and can be extended to prevent a wide range of potential accidents.

Regulatory Requirements Will Never be Adequate The EPA mandates a number of requirements in its regulations; requirements regarding the prevention of accidents, personnel training and contingency planning to name a few. Clearly the regulations can never enumerate all of the necessary considerations that facility management must address to ensure the safe operation of the facility to secure the protection of human health and the environment. Nor would the hazardous waste management industry survive such an enumeration and subsequent bureaucratization of endless regulatory requirements. Indeed the EPA has an entire program dedicated to raising our awareness of accident prevention (http://yosemite.epa.gov/oswer/ceppoweb.nsf/content/index.html.) In one document, a case study of an explosion at a fuel blending facility in Oklahoma, the EPA stated in the introductory paragraph: “Major chemical accidents can not be prevented solely through command and control regulatory requirements; understanding the root causes of accidents, widely disseminating these lessons learned into safe operations are also required.” (EPA 550-F00-001, April 2000, http://yosemite.epa.gov/oswer/ceppoweb.nsf/vwResourcesByFilename/chiefinl.pdf/$File/chiefinl.pdf.)  Let us repeat that: “Major chemical accidents can not be prevented solely through command and control regulatory requirements…” an amazing admission from one of the government’s most regulation prolific agencies.   The EPA is right, but be warned!  The fact that the EPA is making an effort to raise industries’ awareness of accident prevention will not preclude them from adding additional regulations particularly if industry does not respond. Herein lies the purpose of this TechNotes.

Safety Management Systems

The management of hazardous waste is inherently complex. Unlike a chemical production facility, which handles tons of the same 10 or 15 chemicals year after year, a hazardous waste facility handles tons of maybe 100, 200 or more chemicals each year and often at a receipt frequency that lulls management into a routine that has not addressed all of the variabilities that each waste receipt presents. Hazardous waste after all, is a waste not a specification product. This is what is left over (or mistakenly produced) during the production of a product or the completion of a service. It is safe to say that every receipt should be approached as if it were a “surprise” no matter how often similar material has been received or how consistent the generator has been. Yet, exhibiting safe practices beginning at time of receipt is starting way too late. The safe management of hazardous wastes has to start when the facility is first planned and the people first hired and must be systematically unrelenting there after. This may seem boringly obvious and our emphasis of it overly dramatic, but multiple failures of elements of a safe hazardous waste management program are the cause of catastrophic accidents, not that last fatal act by an unaware operator.

Examination of One Accident Points out Many System Failures

In the case study noted above, the story is quite simple. About 200 gallons of waste solvent was mixed with about 2 gallons of dry oxidizers; a mixture of chlorates, perchlorates and nitrates. In less than a minute this exploded out of the mixer fatally engulfing one man and starting a large fire in a building storing flammable liquids. Clearly, mixing flammable liquids with oxidizing chemicals is an unbelievably stupid thing to do - but it happened. It happened because the full nature of the chemical characteristics was not investigated and understood, so that a plan of action could be proposed, that proposal evaluated for safety and the approved plan presented as a standard operating procedure (SOP) and the operators trained to safely execute the SOP. It may be that there was no safe way of doing this, but in that case the initial investigation would have made that determination.

In the end the preventative steps drawn from an examination of this one simple incident are the same ones GCI has advocated after every accident we have investigated and prior to operation of every facility we have set up.  Quoting directly from the case study, those preventive steps are:

·         The chemicals and reaction mechanisms associated with the substances mixed or blended must be well understood and documented. Facilities need to conduct the necessary information searches or laboratory tests to ensure that all reaction mechanisms are known and documented, especially those that may trigger fires or explosions as a result of abnormal situations or changes in chemicals mixed.

·         Chemical and process hazards must be understood and addressed. Once the reaction mechanisms are well understood, facilities need to ensure that process equipment, controls, and procedures are designed, installed, and maintained to safely operate the process. A formal hazard review using techniques like ‘What-If’ or ‘Hazop’ can help identify opportunities for failure (e.g., human error, mechanical failure) and layers of protection to minimize the consequences of such failures, based on established codes and standards, industry practices, regulations (federal or state) and common sense.

·         All employees need to understand the chemical and process hazards. All personnel should openly communicate information about hazards and process conditions and understand the consequences of deviations and unusual situations. Facilities should establish mechanisms for documenting and sharing such information.

·         Standard Operating Procedures (SOPs) are essential to safe operations. Facilities should establish a system to develop and maintain written SOPs and ensure that they are understood and followed at all times. The SOPs must address all phases of operation, safe limits for operation, consequences of deviation, and identification of corrective measures during emergency situations.

·         Before starting a process or procedure that has been changed or modified, the chemical and process hazards must be evaluated. Abnormal or non-routine circumstances are a leading factor in chemical accidents. Facilities should make use of management of change (MOC) and pre-startup safety review techniques to ensure that modified processes or procedures will function as intended without unanticipated impacts on other operations.

·         Employees must be properly trained in the processes they work on using the SOPs for that process or job tasks. Training must include potential hazards, reduction of those hazards, safety consequences if procedures are not followed, and proper emergency response to abnormal situations. Training should contain clear and concise objectives that can be easily evaluated for operator competence.

In some of the more spectacular incidences that GCI has examined every one of these steps were either ignored or truncated.