NARRATOR: Chemicals are essential in our modern world.
They are used by refineries, water treatment plants, pulp
and paper mills, and in almost every other industry
throughout America.
Chemistry has changed our way of life.
Chemicals help produce our plastics and glass.
Chlorine cleans the water we drink.
Hydrofluoric acid boosts the gas in our cars.
But each comes with a risk, including the potential
for an explosive release.
Oil refineries represent one of the biggest risks.
The Chemical Safety Board investigated
167 serious accidents between 1982 and 2002
involving uncontrolled chemical releases at oil
refineries around the nation.
These accidents caused 108 deaths and hundreds of millions
of dollars in property damage.
There are no risk-free refineries.
There's usually something that can go wrong that will
cause serious consequences.
NARRATOR: What would happen if HF were accidentally released?
We were contacted by Amoco oil company
and asked if our expertise in dense gas dispersion
in the atmosphere would allow us to help them assess
hydrofluoric acid and what would happen if it
were released accidentally.
It became pretty clear as we talked that nobody knew exactly
what would happen if there were a large-scale hydrofluoric acid
release.
NARRATOR: Could a mega disaster happen again?
The scenario is hypothetical, but the potential is real.
It's a warm summer day.
And near a quiet residential neighborhood,
an oil refinery is performing routine maintenance.
A series of explosions at the refinery
reaches a large tank of hydrofluoric acid,
and a toxic cloud is released.
The hole is in the side of the tank, and the gas rushes out.
The effects are catastrophic.
In 1987, in Texas City, when the Marathon Oil refinery
released a massive cloud of hydrofluoric acid,
that sent a thousand people to the hospital.
If that chemical had shot out sideways,
it could have killed hundreds of thousands of people instantly.
NARRATOR: The safety systems are overwhelmed
by the rapid release, and the toxic cloud
drifts slowly toward an unsuspecting population.
There's little wind this day.
And the vapor hugs the ground as it drifts ominously
through the neighborhood.
An HF cloud is denser than air.
And it moves downwind with the wind speed.
So if the wind speed is low, the cloud
persists for a longer time.
It stays hazardous for a longer time,
and it goes further downwind.
NARRATOR: Emergency teams are notified,
and the response is activated.
MAN: The sirens are loud.
There are 16 of them in the community,
and they're designed to alert you that there's a problem.
And we can call individuals in the community.
In under 10 minutes, we can call everyone.
NARRATOR: Using a shower of water
as Koopman did in his experiments,
the workers get the situation under control at the refinery.
We found if we applied 40 parts of water
to one part of HF, that that was enough to dilute the HF
and bring it down onto the ground,
and so that it was no longer an airborne hazard.
NARRATOR: But the toxic vapor has
already begun carving a path of destruction in this town.
For those subjected to a high concentration of the HF
even briefly, the exposure can be fatal.
MAN: If there's a chemical leak, you shelter in place.
Studies show us that inside your home,
you're much safer than you would be outside trying to flee.
There might be some exposure, be it limited.
People need to go inside, close all their doors
and windows, turn off their heating and ventilating
air-conditioning systems, seal up the windows if they can,
but basically stay in place until the cloud passes over.
NARRATOR: In places where the cloud is the heaviest,
people don't stand a chance.
The vapor attacks their skin and destroys tissue and bone.
Many will have seizures, and most will die.
By evening, the city begins to take stock of the damage.
The number of dead and injured could be staggering.
It's an extremely reactive gas.
So it reacts with everything that comes in contact with.
And it disperses and is diluted, and finally just disappears
into small quantities.
NARRATOR: This hypothetical scenario has not occurred
yet in the United States.
Many believe it's just a matter of time.
And so for communities in potential danger zones,
being prepared for the inevitable
might be the only solution.