Hermiston Herald
Oct. 25, 2002:

Toxicity levels being revised

By Frank Lockwood
Staff writer

HERMISTON - Revision of the standards which define safe and unsafe levels of
exposure to chemical agent stored at the Umatilla Chemical Depot has created
confusion as to what levels are safe, even as to which agent is more deadly.

The Environmental Protection Agency is in the process of setting safety
standards for a wide range of chemicals, including the aging chemical
warfare agents. Called Acute Exposure Guideline Levels, the AEGLs are
intended advise concerning unsafe limits of exposure, for life and health,
to the general public, and are more stringent than the levels that were used
to advise of likely affects of the chemicals on soldiers during wartime
conditions.

A draft set of the EPA's AEGLs is being revised. An earlier draft of AEGL
rated VX as ten times more lethal than GB. Even earlier estimates were that
VX was less of a risk than GB. Another report claimed VX was 200 times more
lethal than GB. So there has been a some confusion over toxicity levels.

Hackett said the next revised version is likely to describe VX as two to
three times more lethal than GB. At any rate, most reports now say VX is
more deadly than GB.

But which chemical of the two chemicals is a greater risk depends upon a
variety of things, such as whether or not the chemical becomes vaporized.

Although VX is more stable, thus perhaps less of a risk under ordinary
circumstances, if VX gets on one's skin or becomes vaporized, say, through
an explosion, it is also very lethal.

Monitoring the presence of liquid VX is more difficult than monitoring for
liquid GB with the same equipment, because GB is more likely to be giving
off vapor. That vapor, however, is also deadly to humans, depending on the
contractions and the amount of time a person is exposed.