MANY THANKS to my NEW & RENEWING "Partners in Safety"for their support!
Polyone since 7/11, S-Con, Inc since 7/11, Michels Corporation since 7/11, Fluor-B&W Portsmouth since 6/2011, and Suzlon since 2009
Items in this week's newsletter:
RR883 - Vulnerability of oil contaminated fire retardant overalls
What is a “Hybrid Mixture” when talking about flammable vapors and combustible dusts?
A lot of folks know about flammable liquids and their vapors. A smaller group of folks know about combustible dusts. Yet there is a even a smaller group that knows that when a flammable vapor/gas and a combustible dusts are mixed together, both the vapor and the dust will have a LOWER LEL than if they were in an atmosphere by themselves. Here is what happens and why it is important to consider this phenomenon in your safety systems. We call these mixtures "Hybrids". A "hybrid" is where two or more flammable materials of different phases (e.g., a dust and a vapor) are present in the same mixture. Tests have shown that adding a flammable gas to a dust suspension can greatly lower the ignition energy of the dust. This phenomenon is especially true where the gas is present at a concentration below its lower flammable limit (LFL) or the dust is below its Minimum Explosible Concentration (MEC). Such hybrid mixtures can sometimes be ignited even if both components are below their lower limits. A "hybrid" mixture can be formed by the following:
The term "hybrid" applies to any mixture of suspended combustible dust and flammable gas or vapor where neither the dust itself nor the gas or vapor itself is present in sufficient quantity to support combustion but where the mixture of the two can support combustion. Hybrid mixtures pose particular problems because they combine the problems of the high charge densities of powder-handling operations with the low ignition energies of flammable vapors. The MIE of a hybrid mixture is difficult to assess, but a conservative estimate can be made by assuming that the MIE of the mixture is at or near the MIE of the gas alone. Because hybrid mixtures contain a flammable gas or vapor, they can be ignited by brush discharges. It is ABSOLUTELY CRITICAL that this phenomenon be taken into consideration when designing safety systems such as "inerting" the head space of process vessels. Engineers need to realize that when a combustible dusts are added to vessels in the presence of a flammable vapor or gas, that RISKS are INCREASED by a considerable amount. Without the dust in the mixture, the atmosphere in the vessel may not reach the LEL of the flammable vapor; but when personnel begin to add the combustible dusts - the "hybrid mixture" will LOWER the LEL for the flammable vapor AND the combustible dust's Minimum Explosible Concentration (MEC) will also lower in this atmosphere, making ignition that much easier. Coupled with the fact that the dust is a MAJOR source of static electricity, this is why adding powders to flammable liquids is the #1 cause of flammable liquid process explosions. Keep in mind that most of the common hydrocarbons have Minimum Ignition Energies (MIE) well below 1 mj, just a fraction of the energy generated by the falling powder/dusts. With a lowered LEL for the vapor and the combustible dust, this is just a recipe for disaster.
Final Rules on HazCom, Confined Spaces Expected This Year
On July 7, OSHA released its semiannual regulatory agenda, which is a listing of all the planned regulatory actions the agency expects to have under consideration for promulgation, proposal or review over the next 6 to 12 months. According to the agenda, OSHA’s effort to make the agency’s Hazard Communication standard consistent with the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) will be finalized in September 2011. A final rule for confined spaces in construction is expected in November 2011. Other planned final rules include updates to OSHA standards for acetylene and personal protective equipment (PPE) and completed action on the Standards Improvement Project (SIP III), which aims to improve and streamline OSHA standards. Also on the agenda are proposed rules for occupational exposure to crystalline silica, occupational injury and illness recording and reporting requirements for modernizing OSHA’s reporting system, and adding a musculoskeletal disorders (MSD) column to the OSHA 300 Log. Listed in the prerule stage are actions on bloodborne pathogens, combustible dust, infectious diseases, injury and illness prevention program (I2P2), and occupational exposure to beryllium and food flavorings containing diacetyl and diacetyl substitutes. The Dept. of Labor (DOL) held live web chats on planned regulations. The OSHA chat was held Monday, July 11 and a replay of the chat is available on the DOL website. To view a complete list of planned actions for OSHA and other DOL agencies, visit the website of the Office of Information and Regulatory Affairs.
The Department of Homeland Security has PROPOSED a security program for Ammonium Nitrate
DHS published a Notice of Proposed Rulemaking for the Ammonium Nitrate Security Program in the Federal Register on August 3, 2011. The proposed rule would regulate the sale and transfer of ammonium nitrate (AN) to help prevent the misappropriation or use of AN in the act of terrorism. CFATS facilities, regulated for possession of AN, are affected by this proposed rule. Click here for a copy of the proposal. Comments on the proposal are due on or before December 1, 2011; comments on the proposed collection of information is due on or before October 3, 2011.
Cal/OSHA fines prominent pharmaceutical firm $371,000 for confined space safety violations leading to a worker fatality
Cal/OSHA issued eleven citations totaling $371,250 to a prominent pharmaceutical plant for deliberate and willful workplace safety violations which resulted in the death of one of their technicians and serious injury of two others. The violations included four willful citations, indicating intentional violation or knowledge of a violation. On January 21, a technician, 33, collapsed when he entered a seven foot deep, 6,000 liter tank in which nitrogen gas was being bubbled through plasma as part of a protein extraction process. Air in the tank had been displaced by the nitrogen gas resulting in an oxygen deficient atmosphere in the tank. Cal/OSHA regulations require employers to have special protective procedures in place prior to the entrance by employees into these types of confined spaces. In this case, the employer had not tested the atmosphere prior to entrance to insure there was sufficient oxygen, which led to the technician’s death. Cal OSHA’s investigation further revealed that when the technician was discovered, a supervisor ordered two other employees to enter the tank and retrieve him, without testing the atmosphere of the tank or providing proper equipment and other safeguards necessary for a safe rescue. As a result, the technician died and the two employees sent to retrieve him were seriously injured. One remains hospitalized since January. Cal/OSHA determined that the plant’s confined space program failed to comply with all requirements, including appropriate atmospheric testing, protective equipment as well as rescue equipment and procedures. The plant is part of a multi-national pharmaceutical company. The facility is the largest of its kind in the nation, utilizing advanced technology to produce plasma proteins. The citations Cal/OSHA issued included one classified as general and ten classified as serious, four of which were classified as willful. Willful classifications are issued when an employer either commits an intentional violation and is aware that it violates a safety law, or when an employer is aware that an unsafe or hazardous condition exists and makes no reasonable effort to eliminate the hazard.