Thursday 7 May 2020

All you need to know about the deadly gas 'Styrene'​ in LG Chem, Visakhapatnam Reviewed by Dr.Yashoda Tammineni, HOD,HSE at NIFS



All you need to know about the deadly gas that has sickened hundreds of people in Visakhapatnam

The plastic plant( LG Polymers) at visakhapatnam was being prepared to re-open after the entire nation had been under lockdown due to the coronavirus pandemic. The styrene gas leak occurred in the morning, around 2.30-3.00 am IST. People living in a five-kilometre radius of the plant are affected and around 1000-1500 people have been evacuated. About 80-100 people have been hospitalised and at least 10 persons, including two senior citizens and an 8-year-old girl, have died as per the reports.

STYRENE ?
Several millions of tons of styrene are used in the production of polystyrene plastics, resins and in the manufacture of containers for foodstuffs, packaging, synthetic marble, flooring, disposable tableware and moulded furniture. Acute (short-term) exposure to styrene in humans results in mucous membrane and eye irritation, and gastrointestinal effects. Chronic (long-term) exposure to styrene in humans results in effects on the central nervous system (CNS), such as headache, fatigue, weakness, and depression, CSN dysfunction, hearing loss, and peripheral neuropathy. 

Hazardous characteristics
Styrene is flammable, very refractive, with a strong pungent but tolerable and quickly disappearing odour at ambient air levels of 100 ppm. The odour detection limit is around 5 ppm.
The technical material is usually 99.6% pure, and normally contains a very small amount (12 to 15 ppm) of tertiary butyl catechol as a polymerisation inhibitor. When heated to 200°C it is converted into the polymer, polystyrene. Styrene can react violently with oxidizing agents such as peroxides, strong acids, and chlorates.
Fires involving styrene may release dangerous by-products specially carbon dioxiode and carbon monoxide. Fires must be extinguished with carbon dioxide or dry chemical

Target organs are: Central nervous system; skin; respiratory tract; eyes; liver.

High risk circumstance of poisoning
The most likely circumstance of poisoning consists of the inhalation of vapours of styrene, although skin exposure may occur. Pungent odour usually gives adequate warning but the odour disappears rapidly.

Causes of death
Acute exposure to high concentrations may produce signs of upper respiratory irritation, followed by asphyxia, muscular weakness, coma and death from respiratory paralysis.

Effects of short term styrene inhalation on volunteers are according the vapor concentrations: around 350 to 375 ppm for 0.5 to one hour reduction of manual dexterity and coordination and impairment of reaction time. Increasing concentrations (>800 ppm) cause central nervous system depression.

FIRST-AID MEASURES
Remove the victim from the area of exposure and Check the victim thoroughly:

EYES:  
First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician.

IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN:
IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, be prepared to transport the victim to a hospital for treatment.

INHALATION:
IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere.

INGESTION:
DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and be prepared to transport the victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body.

Life Supportive Procedures and Symptomatic Treatment
Make a proper assessment of airway, breathing, circulation and neurological status of the patient. Maintain a clear airway. Administer oxygen if necessary. Start artificial respiration for respiratory failure.

Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, the exposure level and the route of exposure.

It is necessary to follow the safety precautions during the gas leak:
1.   Don’t panic.
2.   Use wet cloth as mask to cover the nose and mouth.
3.   Drink plenty of water.
4.   Wash the face and affected parts frequently with soap.
5.   Consult the physician immediately.

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