Implementing the requirements of Regulation No. 982 “Methods for determining energy infrastructure objects protective zone” issued by the Cabinet of the Republic of Latvia, the joint-stock company “Conexus Baltic Grid” (formed in the result of reorganization of the joint-stock company “Latvijas Gāze” and taken over the operator’s rights and obligations of natural gas transmission system and storage system from the joint-stock company “Latvijas Gāze”) (hereinafter – JSC “Conexus Baltic Grid”) provides information on how to act in case of potential transmission gas pipeline emergency and on the protection measures to be performed.
AS “Conexus Baltic Grid” gas transmission ensures transportation of natural gas through transmission pipeline with the work pressure exceeding 1.6 mega pascals (MPa), and through transmission gas pipeline and the maintenance and development of their objects.
CHARACTERIZATION OF NATURAL GAS HAZARD
Natural gas (main ingredient – methane 97%) is a colourless natural chemical product that is twice as light as the air. Classified as extremely flammable (F+ R12) and explosive only in closed rooms at definite concentration with air (5-15% of volume of space). Natural gas has no odour, taste and colour. To detect timely the natural gas leakage a special substance odorant with characteristic odour – ethyl mercaptan is used in the result of which the gas gets a specific odour. Odorant is added to the gas in the gas regulation stations, it means that the gas is odorized right before it is supplied to the consumers. Natural gas in the transmission gas pipeline systems with pressure more than 1,6 MPa (16 Bar) is not odorized.
Natural gas can get into the body through the respiratory tract. It’s not likely that the product represents risk to human health under the prescribed conditions of use.
The main ingredient of natural gas is methane. It is one of the gases causing the greenhouse effect therefore the product is classified as dangerous for the environment.
The gas at high concentration has asphyxiant effect. Inhalation of gas and air mixture with oxygen content <18% mays cause the central nervous system disorders, headache, weakness, balance disorders and vomiting. Unconsciousness and death is possible at minimum amount of oxygen in the air.
Contact with a concentrated gas jet may cause skin irritation and in separate cases skin frost-bites.
Contact with a concentrated gas jet may cause irritation of mucous membrane and in separate cases frost-bites of mucous membrane.
First aid measures
After eye contact
The gas has no harmful effect if spreads slowly under normal atmosphere pressure and temperature. If concentrated gas jet gets in the eyes, wash them promptly with clean water for several minutes. Call immediately emergency aid.
After skin contact
The gas has no harmful effect if spreads slowly under normal atmosphere pressure and temperature. If concentrated gas jet gets on the skin, it ca cause frost-bites, wash promptly with large amount of clean water for several minutes. In case of frost-bite seek medical aid.
Remove the victim to fresh air. If the victim doesn’t breathe, make artificial respiration. Seek immediately the medical aid.
POTENTIAL ACCIDENTS IN THE GAS TRANSMISSION PIPELINE AND ITS OBJECTS
The following accidents are possible in the gas transmission pipelines and their objects:
- Gas leakage – may occur in the result of non-tight connections ad it can be detected if a fizzing sound characteristic to leaking gas is heard and/or specific odour characteristic to gas is felt. An explosive gas concentration area may form. In this case even a small source of power (such as spark) in this area may cause an explosion.
- Rupture of gas pipeline without ignition – may occur in the result of unplanned mechanical effect or due to incorrect operation of the gas pipeline or their object. Such accident is accompanied by a fizzing sound characteristic to leaking gas and irretrievable damage may occur to the pipeline, their objects and the environment. Similarly, an explosive gas concentration area is formed where even a small source of power (such as spark) in this area may cause an explosion.
- Rupture of gas pipeline with ignition. Rupture of gas pipeline with immediately following explosion and ignition is possible rarely, but is possible and in the result the natural gas leaks from the whole cross-section of pipeline with fill working load and irretrievable damage is caused to the surroundings, buildings and equipment. When detecting such accident, JSC “Conexus Baltic Grid” cuts off immediately the damaged span of gas pipeline, the remaining amount of natural gas escapes from the pipeline or burns and the accident elimination works are commenced promptly.
ACTION OF RESIDENTS IN CASE OF AN ACCIDENT
Take promptly the following measures if you hear an explosion and a fizzing sound characteristic to leaking of natural gas with huge pressure is heard and/or specific odour characteristic to natural gas is felt that evidences a high concentration of natural gas:
- stop any economic or other activity in the result of which a spark may occur, don’t use open flame, disconnect all electric appliances from the grid, switch off engines of cars and mechanisms;
- Look for the shelter in the closest building. If this is impossible, leave immediately the dangerous area perpendicularly to the wind direction (so that wind blows from the side);
Attention! In case of gas pipeline explosion with subsequent burning of gas, there’s a large heat radiation in the area of ca. 600 m so leave immediately this area or don’t approach it.
- Inform the State Fire and Rescue Service about the natural gas leakage by calling 112. Give the location (address), possible place of natural gas leakage, your name, surname and phone number. If possible, ensure that the surrounding persons are informed about the accident and they knw how to act.
- When in the building (preferable in the lowest floors), take protective measures not to permit that natural gas gets in the room:
- open the doors, windows, ventilation hatches, flues;
- seal the gaps in windows, doors, ventilation hatch with a cloth or other material soaked in water.
- don’t use power switches and use butter-muslin – cotton bandages, folded towels, fabric or other air-impermeable materials soaked in water for protection against the harmful effect of natural gas (if breathing is difficult and the mentioned respiratory tract protection materials are unavailable try to hold your breath and make short shallow inhalations).
- Listen to the information given by the fire and rescue service, police and staff of JSC “Conexus Baltic Grid” through the loudspeakers and comply with the instructions (alarm sirens are activated to warn the residents about an accident or a threating accident).
- Get ready for possible temporary movement from the dangerous are in safe distance, or in special cases – evacuation, take with you ID documents, medications, basic goods, money, etc.
- If required, evacuation, temporary accommodation, care and security of the property is performed by the responsible institutions (relevant municipality, State and municipal police, National Armed forces, institutions of the Ministry of Welfare) according to the territorial civil protection plans.
- In case of aggravation of the health condition (headache, weakness, balance disorders and vomiting), go to the closes medical institution or call emergency medical aid by phone 112, 113 or 03.
- Leave the rooms only after the information from the responsible national institutions is received.
Gas transmission of JSC “Conexus Baltic Grid”