Presentation on theme: "Death and injury from H2S exposure is unnecessary"— Presentation transcript:
1Death and injury from H2S exposure is unnecessary Hydrogen SulfideDeath and injury from H2S exposure is unnecessary
2Hazards & Characteristics THE PRINCIPAL HAZARD IS DEATH BY INHALATION!When the amount of gas absorbed into the blood stream exceeds that which is readily oxidized, systemic poisoning results, with a general action to the nervous systemLabored respirations occur shortly and respiratory paralysis will follow immediately at higher concentration.Death will occur from asphyxiation unless the exposed person is removed immediately to fresh air, and breathing stimulated by artificial respiration.
3Other levels of exposure may cause the following symptoms individually or in combinations: Headache- Dizziness- ExcitementNausea- Coughing- DrowsinessDisorientation- ConfusionDryness and sensation of pain in the nose, throat and chestDetection of H2S, solely by smell, is highly dangerous as the sense of smell is rapidly paralyzed by the gas.
4CharacteristicsExtremely toxic, ranking second to Hydrogen Cyanide and five (5) to six (6) times more toxic than Carbon Monoxide.ColorlessOffensive Odor, often described as that of rotten eggs.Heavier than air- vapor density (specific gravity) (Air = 60* F) vapors may travel considerable distance to a source of ignition and flashback.Readily dispersed by wind or air currentsFlammability - Forms an explosive mixture with air concentration between to 46% by volume.Auto-ignition point of 500* F – Cigarettes burn at 1400* F
5Burns with a blue flame and produces Sulfur Dioxide (S02), which is less hazardous than H2S, but very irritating to the eyes and lungs, and can cause serious injury. Chemical pneumonia can develop in a few hours.Soluble in water and liquid hydrocarbons.Produces irritation to the eyes, throat, and respiratory system.Permissible exposure limit (PEL) (OSHA) Threshold Limit Value (TLV)- Maximum of 8 hours exposure without respiratory equipment- 10 PPMCorrosive to all electrochemical metalsBoiling Point (-79*F)Melting Point (-117*F)
7Permissible Limit / Threshold Limit- Concentration at which it is believed that all workers may be repeatedly exposed day after day without adverse effects.Hazardous Limit- Concentration that will cause death with short term exposure.STEL Short Term Exposure Limit- 15 PPM for a duration of no longer than 15 minutes.
8Physical Effects Remember 1% = 10,000 Parts Per Million (PPM) Concentration Physical EffectsPresent (%) PPM Grains/100’ std ft 3(1)Odor ThresholdObvious and unpleasant odorSafe for 8 hours exposureWear Respiratory Protection More Than 15 PPMKills smell in 3 to 15 minutesmay sting eyes and throatKills smell shortly; stingseyes and throat
9Concentration Physical Effects Present (%) PPM Grains/100’ std ft 3(1)Dizziness, breathing ceases in a fewminutes: needs prompt artificialrespirationUnconscious quickly; death will resultif not rescued promptlyUnconscious at once: followed bydeath within minutes.C A U T I O NHydrogen Sulfide is a colorless and transparent gas and is flammable.It is heavier than air and may accumulate in low places.1) At psia and 60*F.
10DetectionKnowing the limitations of your detection devices can save yourlife. When testing, always be prepared for a high concentrationof gas.C A U T I O NDo not rely on your nose to detect H2SFollowing is some common detection devices:LEAD ACETATE, AMPULES OR COATED STRIPS: thesechange colors in the presence of H2S. The Color changeindicates the concentration. For use in low concentrations ofgas. They should be used as alternate method of detection.
11HAND OPERATED TUBE DETECTORS: This type of detector incorporates a pump, color metric detectortube, and a scale that will give a reading of H2S. The pumpdraws air to be tested through the detector tube to react withlead acetate coated silica gel granules. Presence and amountof gas on the tube are shown by the length of color change onthe tube. Read the scale to determine concentration. Specialtubes may be used for SO2 detection and measurement. Foryour protection, it is advised that you take frequent reading withthis type of detector.
12PERSONAL ELECTRONIC MONITORS: The units are usually hand held or belt mounted, and measurethe H2S concentration at the sensor head continuously.Monitors give an audible alarm, some readout, at the presentlevel of H2S.FIXED MONITOR SYSTEMS:Monitors H2S concentration continuously at various locationswhere sensor heads are placed. Alarms are activated whenconcentration reaches set levels. Excessive exposure to waterand acetylene gas can set off some systems.TUTWILER METHOD:Chemical analysis for determining H2S concentrations. The testcan be run on very low and high concentrations, and isextremely accurate and recommended by various stateregulatory agencies.
13ProtectionThere are three categories of breathing equipment you will findon location.Escape Unit (an air capsule)Work Unit (air line with a escape bottle)3. Rescue Unit (30 minutes which can also be used for work)BEYOND 15 PPM OF H2S, ALWAYS WEAR YOURBREATHING EQUIPMENT!Escape Unit are located near work stations. They have asmall, self contained air supply and are designed to give youenough air to reach a safe area in the event of an emergency.
14Work Units allow you to work for an extended period of time in an H2S or poison environment. They have an air line from asupplied breathing air source. The unit also has an auxiliaryself-contained air supply (bottle) for escape.Rescue Units provide a self contained (30 minutes) supply ofair usually carried on your back. The weight is about 35 pounds.DO NOT COUNT ON A FULL 30 MINUTES since time will varywith breathing and work. Audible alarms warn when air supplyis low and you have 5 to 7 minutes of air left. Rescue units mayalso be used as work units.Read the instruction for care, use, maintenance and operationof the 30 minute units on location.
15C A U T I O NFacial hair- glasses- absence of dentures- could cause animproper face seal. Your future and the future of your familymay depend on it. Contact lenses should not be worn incontaminated atmospheres with supplied air respirators.Your breathing equipment will protect you only when you use itproperly. You must care for it, maintain it, and insure you canget a good seal at all times. All breathing equipment, theescape unit, the work unit, and the rescue unit all use grade“D” or “E” breathing air.
16Emergency Rescue Put on your proper respiratory equipment. Move the victim to fresh air at once…Up Wind or Cross Wind.If the victim is unconscious and breathing has stopped. Apply mouth to mouth ventilation immediately and continue until normal breathing is restored.After reviving the victim NEVER LEAVE HIM ALONE.Make sure the victim is seen by a physician for possible underlying condition.R E M E M E B E RCool headed action in a rescue is critical. It is the ONLY HOPEfor the victim, and is the only hope for YOU, the rescuer, aswell. YOU CAN NOT RESCUE HIM/HER IF YOU ARE NOTPREPARED!
17First Aid & Artificial Respiration R E M E M B E RArtificial respiration must always be started as rapidly aspossible because the average person may die in six (6) minutesor less if his/her oxygen supply is cut off. It is often impossibleto tell exactly when a person has stopped breathing. He/shemay be very near death when you first discover them.ARTIFICIAL RESPIRATION(mouth to mouth)Place the victim on his back. If a foreign matter is visible in thevictim’s mouth wipe it out with your finger. Place the palm ofone hand on the forehead and 2 fingers on the bony part of thechin. Lift the chin to open the airway.
18Maintain the chin lift- Look, Listen, and Feel for breathing. If no breathing pinch the victim’s nose closed, take a deep breath.Seal your mouth over the victim’s and give two (2) slow fullbreaths.Check for a pulse at the victim’s neck (carotid pulse) if there is apulse but no breathing then you need to keep breathing for theperson.You should provide at least one breath every five (5) seconds,or twelve (12) per minute. If the victim’s airway is clear, onlymoderate resistance will be felt.
19Watch the victim’s chest, when you see it rise, stop blowing. Raise your mouth and turn your head and listen for exhalation.Watch the victim’s chest to see if it falls. When the victim’sexhalation is finished, repeat the cycle. As the victim attemptsto breathe, coordinate your breathing with his/hers. Afterreviving the victim watch closely and treat for shock.NEVER LEAVE THE VICTIM ALONE, and have someone elsecontact the EMS. Make sure he is evaluated by a physician forany underlying conditions.
20Effects on MetalHydrogen Sulfide is very corrosive to all electrochemical seriesmetals. It can also cause hydrogen embrittlement to steel pipehaving a tensile strength of 95,000 psi or more.Blistering and pitting are two other signs of corrosion that canindicate the presence of H2S.Metal components used in H2S areas should be thosemanufactured to resist Sulfide Stress Cracking (SSC). SSC is acorrosive action causing unsuitable metals to crack undernormal operation.API and NACE have set down the requirements of the metal tobe used in H2S service.
21Location Safety “WARNING NO SMOKING” signs should be strategically located around the rig location. The following locations areappropriate: In the dog house, on the floor, around thesubstructure, lower landing of all stairs to the rig floor, mud pits,shale shacker. Designated smoking area should be set up onall locations.Poison Gas signs should be placed at strategic points on thelocation, such as: entrance to location, lower landing of allstairs to the rig floor, and all areas around the substance.
23BUDDY SYSTEM- When H2S reaches high concentration; workers should team together and work in pairs (BuddySystem). The system is effective only if workers stay togetherand are watching for early signs of H2S poisoning. When morethan 300 ppm, the Buddy System must be used.LANYARDS & SAFETY BELTS- if the distance betweenbuddies must extend more than an arms length, a lifelineshould be secured between them. The lifeline should be atleast a 400 lbs test, soft, fire resistant rope. Also, in high riskareas such as inside vessels, tanks, or in a cellar, workersshould have a life line.
24CASCADE SYSTEM- is a supplied breathing air system usually consisting of 300 cu. ft. compressed air bottles interconnectedto provide breathing air to the workers. The system is set upwith a regulator to reduce the air pressure going to the workarea. From a cascade system low pressure hose(s) connect tomanifold(s) into which each worker can connect the hose linefor his work-escape unit (breathing equipment).BRIEFING AREAS- Each drilling and work over location usuallyprovides at least 2 briefing areas. Briefing areas should belocated on opposite sides of the location in order for one area tobe upwind at all times. The upwind briefing area is theprotection center in the event of an H2S emergency. Allpersonnel should report to this location in an H2S emergency.
25WINDSOCKS-STREAMERS- Wind will disperse H2S very rapidly. Windsocks or streamers should be installed around thelocation for determining prevailing wind and present winddirection. All Personnel On Location Should Develop WindDirection Consciousness.BUG BLOWERS- Large blowers or fans may be used todisperse H2S vapors. In calm and extremely light winds, bugblowers are effective in reducing H2S concentration in the workarea. Bug Blowers should be non spark, explosive proof type.FLARE GUN- In the event of an H2S gas release, and after allmeasures to shut in the well or repair the source of releasehave failed, and the public is in danger, then the flare gun couldbe used to ignite the source of H2S. Also, in the event of failureof the flare pilot light, the flare gun could be used.