Dr. Jeffery H. Kravitz Chief, Scientific Development Mine Safety and Health Administration Cochrans Mill Road P.O. Box 18233 Pittsburgh, Pennsylvania 15236
Dear Dr. Jeffery H. Kravitz,
Monday June 29, 2009, CSE was informed of an incident that occurred Friday June 26, 2009 at Mountain Edge Mining - Dorothy #3 mine during a simulated self-rescuer training session. While we are still investigating the full circumstances underlying this incident, we wanted to furnish you with preliminary findings and suggest steps that should be taken to alert the mining industry regarding avoidance of inappropriate and potentially hazardous training procedures.
Background
As we understand the facts surrounding Friday’s incident, the Dorothy #3 Mine conducted self-rescuer expectation training utilizing the SR-MP Simulator Assembly (designed for class room training) to educate mine personnel with respect to the heat and breathing resistance generated during normal Self-Contained Self-Rescuer (SCSR) use. Instead of a classroom, the training was conducted in the actual mine.
As reported to us, the session was conducted in the Dorothy #3 mine to create a confined space that could be filled with theatrical smoke/fog. It is our understanding that the theatrical smoke was used to replicate the obscuring effects of smoke in a mine fire and to demonstrate the loss of visibility and potential for disorientation that may result from a mine fire underground.
According to initial reports, Mountain Edge Mining purchased 20 SR-MPs Simulator Assemblies and 10 Expectation Mouthpiece Assemblies on January 22, 2009 and 40 SR-MP Replacement cartridges and 10 Expectation Mouthpiece Assemblies on February 9, 2009. In preparation for the June 26, 2009 training session, mine personnel assembled SR-MP Simulator Assemblies for the sessions in an air-conditioned room. Mine personnel removed the SR-MP cartridge from its package and installed the mouthpieces onto the cartridges leaving the bottom cap on the cartridges and placed 10 to 12 units in the original product plastic bag to transport the units into the mine. The first and second training sessions consisted of 10 individuals per session and reported no issues in the performance of the SR-MP. The third session took place about 3:00 PM Friday June 26, 2009 and immediately upon donning the SR-MP, eight individuals complained about a burning sensation and blistering in and around the mouth area while 3 individuals reported no issues with the performance of the SR-MP.
Tentative Findings
Upon notification of this incident, a CSE representative immediately visited the mine to initiate a review of the underlying facts and examine the equipment. Further review and our initial analysis of the facts indicate that while participating in the third training session in the mine, 11 subjects removed SR-MP units from a common bag that had been contaminated with potassium-oxide. The contamination occurred either by previously spent SR-MP units that were inter-mixed in the same bag with new SR-MP units or by previously spent SR-MP units placed in a common bag, later removed from the bag and new SR-MPs placed in the same bag. CSE believes that the spent units had been worn in excess of the prescribed 5 minutes referenced in the user’s manual, causing the potassium oxide to liquefy. It appears that because the spent SR-MP units were placed in a common bag after the completion of the first and second sessions, liquefied potassium-oxide may have contaminated the new SR-MP mouthpieces. CSE was able to verify the presence of potassium-oxide contamination to the SR-MP units used by the mine by applying a chemical agent that reacts with potassium-oxide and turns purple (see attachment 1 and 2). The potassium oxide is classified as a caustic, which would result in chemical burns to any tissue it contacted.
Conclusion
CSE provides product manuals of instruction for use and safety precautions regarding the SR-MP Trainer for customers and end-users. Mine operators must carefully consult product manuals before using the SR-MP. They need to understand that simulations must be done with great care and proper information. The chemicals in the SR-MP are rated as hazardous material, which are potentially dangerous and must be handled and disposed of properly to prevent injury.
For its part, CSE intends, upon completion of its investigation, to issue a user notice reminding customers that they should not use SCSRs or training units unless they have ascertained that they are using the units in a manner consistent with their design and purpose. Users will also be reminded that SR-MP Training units, which are not closed circuit breathing apparatus, must be disposed of properly to prevent possible injury and in compliance with local, state, and federal laws pertaining to disposal of hazardous material. In addition, CSE will reemphasize that training units such as the SR-MP, which are designed and intended for classroom use only, should never be used in a confined space, or in an oxygen deficient or potentially hazardous atmosphere.
The SR-MP Expectation Trainer has provided 40,000 users with a safe, successful, and realistic experience of wearing a Self-Contained Self-Rescuer to date. However, due to the potential for product misuse CSE intends on using calcium hydroxide in the SR-MP Expectation Trainer in place of the current chemical potassium-oxide and will be offering users in the near future the opportunity to exchange their potassium-oxide containing SR-MPs with units containing the calcium hydroxide. In our opinion, the calcium hydroxide will provide the user with simulation training similar to that provided by SR-MPs using the potassium-oxide.
CSE will keep MSHA and NIOSH informed of any additional information it obtains in its investigation and will provide the agencies with an opportunity to review the users notice before it is issued. CSE believes that re-education and product modifications can minimize the risk to miners of injuries of this type created when the units are not used in the proper environment and mishandled following training.
CSE urges your office to disseminate an accurate account for the events and its action plan to remedy the mishandling in the field.
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