HYDROGEN SULFIDE MONITORING PROCEDURE

Hydrogen Sulfide Monitoring, Safety and Environmental H2S

Course Objective 

To prepare employees for the hazards of working around H2S & how to properly protect themselves in an H2S Environment.

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Class Topics

General Properties

Flammability

Irritant

Corrosiveness

Toxicity

Monitoring

Exposure Limits

Rescue

Symptoms of Exposure

Respiratory Protection

General Properties 

Invisible 

Flammable

Explosive 

Toxic

Odor of Rotten Eggs 

Corrosive 

Water and Oil Soluble

Heavier than Air

H2S is an Irritant 

When H2S mixes with water it forms a weak acid. 

There’s water in our eyes, nose, throat and respiratory system which leads to irritation. 

Examples: burning eyes, sore/scratchy throat, coughing, respiratory irritation.

Hydrogen Sulfide Gas is trying to kill you in three different ways!

Toxicity  

• We breath in oxygen and the gas exchange take place through the air sacks alveoli in our lungs.
• We then breath out some O2 and CO2.

H2S blocks Oxygen from bonding to   your Red Blood Cells causing Oxygen Deprivation.

H2S blocks Oxygen from bonding to   your Red Blood Cells causing Oxygen Deprivation. 

H2S is also transported to the brain by the Red Blood Cells. 

• Once H2S is in the brain, it attacks the Respiratory Control Center. 
• H2S seeks to shut down respiratory system 
• Slow it down at lower concentrations 
• It deadens your sense of smell! 
• Never trust your nose to detect H2S.

H2S mixes with the water in our lungs forming a weak acid. 

• Weak acid in the lungs attacks the alveoli. 
• Alveoli blister and burst. 
• Victim aspirates on own blood and puss, also known as Pulmonary Edema.

Exposure Limits 

• P.E.L. = Permissible Exposure Limit.
• Defined as the maximum air concentration you can be exposed to in an 8-hour period, 40 Hour Week, without respiratory protection. 
• Established by O.S.H.A., making it a LAW.

ppm stands for parts per million

• I.D.L.H. = Immediately Dangerous to Life and Health.
• I.D.L.H. H2S = 100 ppm 
• S.T.E.L. = Short Term Exposure Limit, based on a 15 Minute Time Period.
• S.T.E.L. H2S = 15 ppm

Knocked out immediately, death in 3-­5 minutes.

Symptoms of Exposure 

• These are your last line of defense.
• Commit these to memory. 
• You may not experience each one of these as everyone’s physiology is different.
• Burning Eyes 
• Sore Throat 
• Respiratory Irritation 
• Coughing 
• Headache 
• Dizziness 
• Nausea 
• Fatigue 
• Confusion 
• Loss of Sense of Smell

Flammability

• H2S is a highly flammable & explosive gas. 
• H2S fires produce a toxic gas.

Flammability Range

Over 46% = Too Rich to Burn

U.E.L. H2S = 46% or 460,000 ppm

L.E.L. H2S = 4.3% or 43,000 ppm

Below 4.3% = Too Lean to Burn

Sulfur Dioxide 

• The main byproduct of an H2S fire is Sulfur Dioxide/ SO2. 
• P.E.L. SO2 = 2 ppm 
• I.D.L.H. SO2 = 20 ppm
• Sulfur Dioxide is highly toxic. 
• It is water soluble and forms a weak sulfuric acid when mixed with water. 
• It can suffocate its victims. 
• It will also burn up your lungs from the inside by forming acid and destroying the alveoli.

Corrosiveness 

• H2S corrodes carbon steel readily. 
• The oxidation rusting on the surface of the metal forms Iron Sulfide Scale, or black scale. 
• Iron Sulfide Scale is pyrophoric.

Iron Sulfide Scale 

• Iron Sulfide will flash as it dries and is exposed to air. 
• This can be a serious hazard when working on pipelines, flow lines, tanks and the like.

Corrosiveness 

• H2S weakens Carbon Steel causing it to become brittle and break. 
• Why or where would this be a hazard in the field?

Monitoring 

Two types of monitoring: 

1. Personal Monitors 

2. Fixed Monitors

Personal Monitors

                                                        

• Small & Convenient
• Easy to Use 
• Monthly Bump Checks
• Yearly Calibration
• Wear on your hip. 
• Keep the Sensor Head exposed. 
• Alarms will sound at 10 ppm, why 
• Alarms can be sounds, lights, vibration or any combination of the three. 
• Take care of your monitor!

Fixed Monitors 

• Found on Rigs, Well Sites, Refineries, Storage Facilities, etc. 
• Sound at the P.E.L. 
• Alarm usually consists of light as well
• TRUST the fixed alarms! When monitors go off, leave and move to the safe area immediately.

Stay Wind Smart 

Well Head 

• Always pay attention to the flags or wind socks. 
• When alarms sound, retreat cross wind to the safe briefing area.

Rescue 

• H2S kills many of us when we don’t think, or aren’t trained, and we attempt a rescue.
• Remember, always protect yourself first, then assist any victims in an H2S emergency.
• If you do rescue of victim of H2S, be careful when providing rescue breathing. 
• Above all else, follow your company’s policy on rescue. 
• Never, ever, rescue unless you can do so the right way!

In Order to Rescue

• You must be rescue trained, 
• Use the Buddy System, 
• You must be CPR & 1st Aid Trained, 
• You must be trained for the specific environment, in this case, an H2S environment,
• You must use the correct Personal Protective Equipment P.P.E.
• Maintain good communication with other rescuers and off site personnel, 
• Notification of E.M.S., 
• Follow your Emergency Action Plan

Respiratory Protection 

• The only type of Respiratory Protection allowed in an H2S Environment is

Positive Pressure 
Supplied Air 

Positive Pressure Supplied Air 

• Constant Flow of Air in Mask.
• Pushes Air out of Leaks instead of letting you pull toxic gasses in. 
• Not filled with pure oxygen, but Grade D air.

Three Types of Respirators for H2S Environment

• Escape Pack: 
• Five Minute Tank 
• Bag or Tight Fitting Facepiece 
• Not for Rescue, Work or Testing!

Escape Unit

• Work Unit: 
• Also called a Supplied Air Respirator or S.A.R. 
• 5 Minute Escape Tank 
• Mask 
• Up to 300’ of Line supplying the user with air. 
• Tied into a cascade or compressor
• Rescue/Testing – S.C.B.A.: 
• Self-Contained Breathing Apparatus 
• Mask, harness and 2216 psi Tank 
• Always turn valves away from you to get more air.
• Will a 30-minute air pack last 30 minutes 
• No – A 30-minute air pack will not last 30 minutes.

Self-Contained Breathing Apparatus

Respiratory Protection 

• Check out your equipment and make sure that it is properly maintained.  
• Only use Positive Pressure Supplied Air in H2S environments. 
• Fit testing is required yearly
• No facial hair other than a neatly trimmed mustache.
• Fit Testing is done to ensure that your respirator will work when it counts. 

There are two type of Fit Tests:

• Qualitative Fit Testing checks the quality using a smoke or odorant
• Quantitative Fit Testing assigns a numerical Fit Factor using a pump system and computer.
• Fit Tests require that a Medical Exam/ M.E.Q. be completed prior to the first test, 
• Or after any major changes in physiology or a serious illness. 
• M.E.Q. is a questionnaire filled out by the employee and reviewed by a P.L.H.C.P.
  

Things that make a fit test fail

Facial Hair  Glasses  Mask Size/Type  Jewelry  Grease or Dirt  Facial Structure

Remember that your company is  responsible for providing you with a  mask that fits, but it’s your responsibility  to maintain the condition of the mask  and avoid any facial hair or other issues  that may interfere with the fit of your  mask.

Training Issues

• Quality of training. 
• Employee attitude. 
• Management attitude. 
• Bilingual Training.

Thanks You!

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