How styrene affects Humans & Animals


Vizag gas leak: How styrene affects humans, animals

      WHY IN NEWS:

Exposure to 20 parts per million of styrene over eight years of working around styrene increases reaction time in subjects

SYLLABUS COVERED: GS 3:Health : Disaster Management


For PRELIMS it is important to know the chemical and its composition . How it reacts and its side effects on the population.


Styrene is a colourless, or light yellow, flammable liquid primarily used in the production of polystyrene plastics and resins – it is used in the manufacture of containers for foodstuffs, packaging, synthetic marble, flooring, disposable tableware and moulded furniture

Styrene affects on Humans & Animals | UPSC

  • The gas was confirmed to be styrene or vinyl benzene by RK Meena, the district commissioner of police.


  • It is used in the production of polystyrene plastics and resins.

These materials are subsequently used in food packaging, rubber, plastic, insulation, fiberglass, pipes and automobile parts.

  • It is also known as PVC gas (polyvinyl chloride), as it is used in the production of PVC.


  • Styrene is the 20th most-used chemical in the world, according to the World Health Organization.
  • The chemical can be found in air, water and soil once released into the environment.
  • It is broken down in air in 1-2 days, while it evaporates from soil and shallow water surfaces.
  • It is broken down by micro-organisms if it reaches soil.
  • It can enter the human body through breathing, eating food and contact through skin.

Once it enters the human body, styrene takes a few days to break down into other chemicals and pass through urine.


  • It is the most harmful in its most basic form as a monomer (a single unit of styrene).

When humans are exposed to styrene, it causes eye irritation and gastro-intestinal effects.

  • It also impacts the outer layer of tissues in the skin causing erosion and bleeding in the short term
  • It also leads to an increase in the colour confusion index that may lead to colour blindness.
  • Animal studies show they are more sensitive to styrene exposure and suffer greater effects.


  • The International Agency for Research on Cancer (IARC) has determined that styrene is a possible carcinogen and can cause cancer under long exposure.

Long-term effects include central nervous system dysfunction, depression, hearing loss and peripheral neuropathy (a numb feeling in the hands and feet).

  • Several epidemiological studies suggest there may be an association between styrene exposure and an increased risk of leukaemia and lymphoma.
  • The EPA also suggested that “human studies are inconclusive on the reproductive and developmental effects of styrene”.

      IASbhai WINDUP: 

Several studies did not report an increase in developmental effects in women who worked in the plastics industry, while an increased frequency of spontaneous abortions and decreased frequency of births were reported in another study, the EPA noted.

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