H2s English

7.2 Hydrogen Sulfide (H2S) Hazard Awareness 7.2.1 Introduction : Hydrogen Sulfide (H2 S) is one of the most toxic dangerous gases in the oil and gas industry. It is absolutely essential that all employees have a clear understanding of the very hazardous nature of H2S, the recognition of its presence, and the procedures to be followed in order to protect themselves from its lethal effect if H2S is released into the atmosphere. H2S may be released into the atmosphere during operations such as drilling, draining, venting, sampling and when process equipment or pipe work is opened for maintenance work. It can also be released to the atmosphere due to the leakage of crude oil or natural gas containing H2S. The purpose of this code of safe practice is to aid the understanding of all personnel and to clarify safe working procedures for personnel who may be exposed to H2S. H2S KILLS SO BE AWARE - BE SAFE 7.2.2 H2S Properties & Toxicity H2S is a highly toxic gas. It is colorless and is heavier than air; however it is readily dispersed by wind movement. It is flammable and, if ignited, will burn with a blue flame, producing Sulfur Dioxide (SO2) an irritating and also very toxic gas with a pungent odor. H2S has a characteristic 'rotten eggs' odor, which can be smelled in Concentrations as low as 0.1 part of gas per million parts of air by volume (ppm). DO NOT DEPEND ON SMELL TO DETECT H2S. The odor is very unreliable way of detecting this poisonous gas since at concentrations between 100-150 ppm, the sense of smell is rapidly deadened. At low concentrations, H2S causes irritation to the eyes, nose and throat, and in high concentrations can be rapidly fatal due to lung paralysis. The Threshold Limit Value (TLV) is the time weighted average concentration for an 8 hours a day or 40 hours a week to which nearly all workers may be repeatedly exposed without adverse effect. The TLV for H2S is 10 ppm. 7.2.3 Detection of H2S

Your sense of smell is usually first in warning you of the presence of H2S, but unfortunately may be the last. DO NOT RELY ON YOUR SENSE OF SMELL TO TELL YOU HOW MUCH H2S GAS IS PRESENT -

Portable H2S Detector Alarm

This instrument is designed as personal protection for workers exposed to H2S hazards. It measures H2S concentrations and gives an audible alarm when the concentration is 10 ppm or greater. 7.2.4 Personnel Protection Upon emergency, all involved staff must wear the provided escape mask immediately. If safe, try to stop operations and leave site in safe condition then follow site escape procedures of client.

6.7 H2S Rescue & First Aid Procedure In the event of an emergency where a person has been overcome by H2S - remain calm - THINK! If you are an authorized person then : 6.7.1 PUT ON A BREATHING APPARATUS BEFORE ATTEMPTING TO RESCUE A PERSON IN TROUBLE. IF YOU DO NOT - YOU TOO CAN BECOME A VICTIM OF H2S.

6.7.2 Move the victim to a safe (fresh air) area. (Go upwind of source of H2S release NOT downwind). 6.7.3 If victim is not breathing, start artificial respiration immediately. 6.7.4 Call medical help. Keep victim warm. 6.7.5 Continue giving artificial respiration until the doctor arrives. 6.7.6 If available, use a resuscitator, but only if properly trained in its use. 6.7.7 If the person eyes are affected, wash well with clean water. NOTES :

•

If a person suffers minor exposure to H2S, and has not been completely unconscious, it is recommended that he rest for about 8 hours, in order to attempt getting his reflexes back to normal.

•

If a victim is moved to fresh air and normal respiration is restored before the heart action ceases, then fairly rapid recovery usually occurs.

6.8

Protection of Personnel Against H2S

Careful planning is necessary when work is to be carried out in an area where H2S is a potential hazard. Problem situations should be eliminated beforehand, NOT when LIFE is at risk. Working procedures in H2S risk areas and on H2S equipment must be strictly controlled at all times. Safety precautions should include the following: 6.8.1

All personnel to know how to approach the work site taking into consideration wind direction, and movement of personnel.

6.8.2 Elimination of all sources of ignition because H2S is extremely flammable. 6.8.3 Use of escape mask. 6.8.4 Availability of at least two escape-routes 6.8.5 Air monitoring or detection equipment with appropriate alarm system. 6.8.6

Observation of warning signs. 6.8.7 Use of reliable communications.