https://www.linde-gas.com/en/images/Campaign%20against%20asphyxiation_tcm17-13907.pdf
Share this newsletter with all your employees and contractors. It may save a life.
https://www.linde-gas.com/en/images/Campaign%20against%20asphyxiation_tcm17-13907.pdf
Share this newsletter with all your employees and contractors. It may save a life.
On Tuesday 17th May, a worker received serious cryogenic burns after immersing their hands in a container of liquid nitrogen whilst trying to shrink a brass bush for inserting into an excavator boom arm.
How did it happen?
The worker was not wearing the correct personal protective equipment for the task. Further details related to the incident are not available at this time
Key issues
Liquid Nitrogen
Liquid nitrogen is one of the cryogenic liquids commonly used in the mining industry. As “cryogenic” means related to very low temperature, it is an extremely cold material. Liquid nitrogen has a boiling point of negative – 195.8 degrees centigrade and can expand to a very large volume of gas.
The vapor of liquid nitrogen can rapidly freeze skin tissue and eye fluid, resulting in cold burns, frostbite, and permanent hand and eye damage, even by brief exposure.
Liquid nitrogen expands 695 times in volume when it vaporises and has no warning properties such as odour or colour. Hence, if sufficient liquid nitrogen is vaporised to reduce the oxygen percentage to below 19.5%, there is a risk of oxygen deficiency which may cause unconsciousness. Death may result if oxygen deficiency is extreme. To prevent asphyxiation hazards, handlers must make sure that the work area is well ventilated.
Without adequate venting or pressure-relief devices on the containers, enormous pressures can build upon evaporation. Users must make sure that liquid nitrogen is never contained in a closed system. Use a pressure relief vessel or a venting lid to protect against pressure build-up.
Handling Safety Practices
Liquid nitrogen should be handled in well-ventilated areas.
Handle the liquid slowly to minimize boiling and splashing.
Use tongs to withdraw objects immersed in liquid nitrogen - Boiling and splashing always occur when charging or filling a warm container with liquid nitrogen or when inserting objects into the liquid.
Use only approved containers. Impact resistant containers that can withstand the extremely low temperatures should be used. Materials such as carbon steel, plastic and rubber become brittle at these temperatures.
Only store liquid nitrogen in containers with loose fitting lids (Never seal liquid nitrogen in a container). A tightly sealed container will build up pressure as the liquid boils and may explode after a short time.
Never touch non-insulated vessels containing liquid nitrogen. Flesh will stick to extremely cold materials. Even non-metallic materials are dangerous to touch at low temperatures.
Never tamper or modify safety devices such as the cylinder valve or regulator of the tank.
Liquid nitrogen should only be stored in well-ventilated areas (do not store in a confined space).
Do not store liquid nitrogen for long periods in an uncovered container.
Cylinders should not be filled to more than 80% of capacity, since expansion of gases during warming may cause excessive pressure build-up.
Eye / Face ProtectionSuitably rated full face shield over safety glasses or chemical splash goggles are recommended during transfer and handling of liquid nitrogen to minimise injuries associated with splash or explosion.
Skin Protection
Suitably rated, loose-fitting thermal insulated or leather gloves, aprons, long sleeve shirts, and trousers without cuffs should be worn while handling liquid nitrogen. Safety shoes are also recommended while handling containers. Gloves should be loose-fitting, so they are able to be quickly removed if liquid nitrogen is spilled on them. Insulated gloves are not made to permit the hands to be put into liquid nitrogen. They typically only provide short-term protection from accidental contact with the liquid.
Source: https://www.rshq.qld.gov.au/safety-notices/mines/use-of-liquid-nitrogen-in-the-mining-industry
At approximately 2 a.m. on August 8, 2001, Employee #1 was working on top of a reactor under nitrogen purge. A coworker was wearing breathing air with a communication device. The lead man was on top of the reactor overseeing the job. The lead man turned around and began communicating on the headset with the workers monitoring the breathing air. Employee #1 walked past the lead man and the coworker without breathing air and reached into a manhole. Employee #1 was overcome by the fumes/vapors and fell 3 to 4 feet into the reactor. The coworker and lead man pulled Employee #1 out of the reactor, and the lead man performed CPR until the rescue team arrived. Employee #1 was pronounced dead at the hospital. Employee #1 died from asphyxiation.
Source:Osha.gov
Employee #1 was inside a frac tank shoveling residue (called BS) to one end of the tank for subsequent vacuuming and removal. As he completed the task, the tank was washed down with waste water containing hydrogen sulfide. Approximately 8 minutes following the waste water entrance, Employee #1 collapsed from exposure to the chemical. Employee #2 entered the tank and attempted to rescue Employee #1, but he too collapsed. Apparently Employees #3 and #4 entered the tank and attempted a rescue and but succumbed also. Employee #5 attempted to revive Employee #1 through an opening at the end of the frac tank. He was affected by the hydrogen sulfide gas but was able to call the city's first responders. Employees #1, #3, and #4 died of hydrogen sulfide exposure. Employees #2 and #5 were hospitalized.
Source:Osha.gov
"Sewage systems on vessels are known as Marine Sanitation Devices (MSDs) or Collection, Holding and Transfer Tanks (CHTs). Cleaning these systems is required for operations such as routine surveys and surface preservation, equipment modification, repairs and maintenance. Entering and cleaning
sewage tanks, piping and components present specific hazards to workers that put them at risk for injuries and illnesses if they are not properly protected (29 CFR 1915.13).
Workers are often exposed to dangerous atmospheres during tank opening and venting; manual pumping and stripping; breaking or dismantling components and piping; and pressure
washing, mucking, and scaling (29 CFR 1915.11(b); 1915.12). A dangerous atmosphere may expose workers to the risk of death, incapacitation, injury, chronic or acute illness, or impaired ability
to escape unaided from a confined or enclosed space (29 CFR 1915.11(b)). When working on CHTs/MSDs, special attention should be given to good hygiene practices, proper use of personal
protective equipment and safe confined space entry procedures (29 CFR 1915.88; 1915 Subparts B & I).
The information in this document can help prevent exposing workers to the known and unknown dangers of handling treated or untreated sewage and gray water tanks during tank opening, entry,
cleaning and related operations. Related components/operations include: piping, aeration, vacuuming, settling, and treatment tanks and apparatus; sewage-contaminated water tanks or waste oil
tanks, bilges, or sumps; and valves, pumps, grinders, macerators and other contaminated equipment".
https://www.osha.gov/sites/default/files/publications/OSHA_FS_3587.pdf
Source:Osha.gov
https://www.aiche.org/ccps/control-hazardous-energy-lock-out-and-tag-out
"Lock-out and tag-out (LOTO) is a critical part of a strong all-around
safety program. In LOTO, maintenance employees work with production
employees to positively prevent all forms of hazardous energy from
causing harm. Hazardous energy comes in many forms. Electrical energy
can cause electrocution and burns, provide ignition to flammable
atmospheres, and activate mechanical equipment. Steam can cause burns or
initiate hazardous reactions. Nitrogen can cause asphyxiation. Chemical
flow can cause uncontrolled reaction and injury. When a piece of
equipment is being worked on, all sources of hazardous energy must be
securely and positively locked out until the equipment is
operational. Untold numbers of major process safety incidents and
individual injuries have been caused by failure of LOTO. A prime example
is the Bhopal catastrophe, one of the worst incidents ever to have
occurred, which was caused in part by the failure of LOTO. Recently, a
company process safety manager called CCPS asking for help in persuading
a newly acquired facility within his company to implement a LOTO
program. The manager was frustrated because, as the plant director
stated, “We understand completely that maintenance workers are
endangered if power or material flow were allowed to equipment they are
servicing. That’s why no one would ever activate a switch or valve
during a maintenance activity. LOTO is just extra, unnecessary
work.” The company process safety manager knew that with the plant
director’s attitude, the plant could be on the road to disaster. Could
CCPS help him make the case for LOTO? At CCPS, we firmly believe that it
is better to learn from the mistakes of others rather than to learn by
painful, personal experience. So we asked CCPS member companies to give
us examples of accidents caused by LOTO failures, and to provide
testimonials about the importance of LOTO. The purpose of this article
is to share this information with you, to help you lead the
implementation or improvement of LOTO in your
company. A brief overview of LOTO procedures and tools are provided, as are references to more detailed resources."
Reference: https://www.aiche.org/ccps/control-hazardous-energy-lock-out-and-tag-out
"Operatives and technicians must frequently climb into pressure vessels in order to perform construction, maintenance, repair and inspection work. However, the access points through which they must pass for this purpose are often so small that although access is possible, rescuing these personnel in the event of an accident presents considerable difficulties. The Polytechnic University of Milan has conducted a number of studies into this issue in the course of two degree theses."
SEE THE LINK FOR FULL ARTICLE
At 12:00 p.m. on April 19, 2019, Employee #1 and Employee #2 were observing a food establishment's sanitation and cleaning process during an investigation. During the observations of the employees and processes, they used a foaming cleanser, quaternary ammonium, and a spot acid clear for cleaning and sanitizing. A pungent smell believed to be chlorine was being released into the air. Employees #1 and #2 noted that their eyes, skin, and mucosal linings of the mouth, throat, and nose were irritated and burning. Employee #2 measured the quaternary ammonium solution, and it was found to be in excess of 200 PPM, which is higher than recommended levels. Hospitalization was not required.
Source:osha.gov
To help ensure that workers do not inadvertently hook up to inert gas supplies, the following recommendations should be implemented:
•Ensure that all requirements related to respiratory protection as outlined in29 CFR 1910.134 are met. Written standard operating procedures governing the selection and use of respirators must be developed and implemented. Requirements for training and instruction in the proper use of respirators and their limitations must be met at all facilities.
•Ensure (determine) that the couplings of the respirator air lines are incompatible with any other couplings/fittings for non-respirable air or gas delivery systems.Replace couplings on non-breathing air systems with another, incompatible type of coupling.
•Ensure that breathable air systems are not in any way interconnected to non-breathable air systems.
•Develop a maintenance procedure to address supply-line identification (labeling)and painting. Stress the purpose of color coding and the importance of completing detail painting in a timely fashion to ensure that this visual cue is always available to aid workers.
Source: Osha.gov
An employee hooked the fresh air line of his supplied-air respirator into a plant’s compressed airlines and began abrasive blasting. The plant operators, unaware that their plant air was being used as breathing air, shut down the fresh air compressor for routine, scheduled maintenance and pumped nitrogen into the system to maintain pressure and control the valves in the refinery. The employee was overcome by the nitrogen in the airlines and died of nitrogen asphyxia.
Source:Osha.gov
An employee was using an air hammer to chip residue out of a furnace at an aluminum foundry.He was wearing an air-line respirator. Two compressed gas lines with universal access couplings were attached to a nearby post. The one on the right was labeled “natural gas.” The gas line on the left had a paper tag attached with the word“air” handwritten on it; however, this line actually contained pure nitrogen. A splitter diverted one part of the gas stream to the air hammer and the other part of the stream to the air-line respirator.The employee was asphyxiated and killed when exposed to pure nitrogen.
Source:osha,gov
A contractor crew was assigned to abrasively blast inside a reactor vessel at a petrochemical refinery.Although verbal company policy called for contractors to supply all breathing air, this crew,with supervisor’s knowledge, had on several occasions used plant air to supply breathing air. A crew member mistakenly hooked up his air-line respirator to an unlabeled nitrogen line (only the shut-off valve was labeled) used by the refinery for purging confined spaces. Plant nitrogen and airlines were identical, and both had couplings compatible with the coupler on the respirator. The crew member was killed.
Source: osha.gov
A fire started at the manhole of an inspection pit for underground pipes of a petroleum storage depot during a welding operation as part of maintenance work on the piping supplying a tank. The underground pipes were feeding eleven tanks in different conditions. At 11:15 a.m., a leak of premium-grade gasoline occurred, followed by a sudden flash. Site technicians attempted to extinguish the ensuing pool fire. The operator activated the internal emergency plan, issued the order to close all motorised valves and called for assistance from petroleum industry partners. At 14.00, emergency responders were still unsuccessful in suffocating the fire with sand. At 15:20 an explosion occurred which was caused by two acetylene cylinders used in the welding operation. Fed by an unknown source, the fire continued to rage for several hours despite firefighting interventions. Eventually, the foot valve on the adjacent gasoline tank was found open by the firefighters. After its closure, the fire receded Intervention efforts were substantial and the toll quite heavy; 15 firemen were burned during the accident: 2 of them were badly hurt, 5 seriously and 8 slightly. Apparently, the firemen suffered burn injuries due to a gust of wind and for the cylinders' explosion. The entry valve of the adjacent tank was left open for an unknown reason.
Important findings
• According to the site
director, the piping should have been submerged in water during the
onsite works and therefore was omitted from the valve closure checklist
and control diagram.
Firefighters encountered myriad difficulties, in particular:
• The fire route to the tank was submerged under a layer of burning hydrocarbons;
• Fire water pipes burst under the weight of vehicles evacuating the zone;
• Lack of information about the source of the fire.
Lessons Learned
• The accident scenario was not
included in the site’s risk assessment study. Fires initiated from
welding operations are abundant in the literature. A hazard assessment
of tank maintenance operations should examine all possible ignition
scenarios (what if?) associated with hot work.
• In order to prevent
subsequent fires or explosions to occur, ignition sources, such as the
acetylene cylinders should be removed from the area of emergency
operation.
• Operators should provide accurate information on
location of safety instrumentation to the emergency responders as soon
as possible, especially if such devices can contribute to the fire or
explosion.
Source: European commission