Health authorities of Ukraine are not taking any chances. Following an atmosphere poisoning of ignited yellow phosphorous, they have examined around 16, 000 people for possible symptoms of toxic poisoning.
The incident near the Polish border (outside Lviv) was caused by a train derailment, which led to its crashing into parked tankers holding the chemical.
Health practioners examined thousands of emergency workers and residents in the region, as clouds of searing noxious gas, filled the skies. According to minister Yuriy Haydayev, more than 180 people remain hospitalized. This includes 34 children.
Quick to point out that not everyone hospitalized had serious symptoms, Haydayev was quoted: "We hospitalized all children who feel discomfort in their eyes or throats, at their parents' insistence, but this does not mean they were poisoned."
There are no reported deaths so far.
The accident occurred Monday when a freight train derailed and caused an overturning of 15 of 58 cars. Six tanker cars containing yellow phosphorus caught fire, sending noxious fumes over 35 square miles.
According to Transport Minister Mykola Rudkovsky the pressure valves were broken on the aging tankers, which should have been decommissioned five years ago. As of now, Ukraine has suspended rail shipments of yellow phosphorus.
According to officials, rescuers have righted three of 15 overturned tanker cars, and will transport them back to Kazakhstan, where they came from. Firefighters sprayed fire-suppressing foam on the damaged tankers to prevent new blazes.
Phosphorus compounds are used chiefly in fertilizers, although they are important components of pesticides, toothpaste and detergents, as well as explosives and fireworks.
Elemental phosphorus can ignite on contact with air in temperatures above 40 degrees Celsius (104 degrees Fahrenheit), and can cause liver damage if ingested.
About 50 million tons of cargo - 70 percent of which include dangerous substances like chlorine, nitrogen, ammonia and petroleum products - are transported by rail through Ukraine annually.
This chemical blaze and health threat is sending jitters down Ukraine, where the memories of the 1986 explosion and fire at the Chernobyl nuclear power plant still hang afresh.