Testing began last week at Groveton High School to determine if toxic fumes are causing illnesses for students and faculty who use the school's vocational wing.

In the past several months, a growing number of students and teachers using that part of the building have complained of a variety of illnesses, including chest pains, headaches, respiratory problems and fatigue.

Several persons in the wing blame the school's ventilating system -- which they say mixes toxic gases from several laboratories and distributes the fumes -- for the outbreak of sickness.

School officials, however, insist the ventilation is adequate and say they are baffled by the complaints.

In reponse to the complaints from students, parents, teachers and the Fairfax Education Association, school administrators have commissioned an independent laboratory to measure toxins in the air.

School officials said that tests conducted earlier this year by the state health department did not indicated abnormally high levels of airborne toxins.

Critics argued, however, that the tests were carried out on days when the wing was not in use and toxic levels were low. School officials agreed to series of tests on days when all divisions in the wing are in "high gear."

The problem, claims auto mechanics teacher Ron LaPorte, is that the ventilating system mixes 20 percent fresh air with 80 percent stale air. The stale air comes from several different labs producing a variety of toxins. From the cosmetology lab comes ammonia, from the print shop ether and from the auto shop carbon monoxide and paint fumes, LaPorte said.

It is the mixture of these gases that LaPorte and several other teachers insist is making them sick.

"The design of that system is not unusual," said Alton Hlavin, director of the school system's design and construction department."We have the same system in some of our other (schools') vocational wings."

One cosmetology student became ill enough during class several weeks ago and required require emergency treatment at Mount Vernon Hospital. According to witnesses, the student became ill after several hours in the lab and suddenly began hyperventilating and gasping for air. Oxygen was administered on school grounds before she was taken to the hospital.

"They've been dropping like flies," said cosetology teacher Susan Sunbury of her students last week.

School officials say they have been responsive to the complaints and point to the Virginia test results as evidence that there are no dangerous toxins in the air.

"We hope to have results of the (new, independent) tests back to us by June 6," said Hlavin.

Hlavin said the testing, orginally scheduled for two weeks ago, was postponed after a shop teacher became sick on the first day of scheduled testing.