Mention the letters ''VX'' or the word ''Sarin'' to Kevin J. Beltis, and he's likely to say, matter of factly, that they are two of many ''organophosphorus chemicals.''
Let those words cross your lips in the presence of Francis H. Duehay, and he is likely to say that these are dangerous nerve-gas agents capable of inflicting ''thousands of deaths within seconds.''
These two people represent two sides of an issue the likes of which Cambridge hasn't seen since the city passed strict regulations on research on recombinant DNA in 1981.
Mr. Beltis is the laboratory operations manager of Arthur D. Little Inc.'s Levins Laboratory, where the company is using small quantities of VX, Sarin, and other nerve- and blister-gas agents in research for the United States Department of Defense (DOD).
Mr. Duehay is one of the Cambridge city councilors who were caught off guard when they learned that Arthur D. Little Inc. (ADL) was conducting this research in an area adjacent to Route 2 (a major Boston access highway) and near residential housing. He voted, along with all of the Cambridge city councilors, to ban the research until a city-appointed Scientific Advisory Committee could study risks to public health that are believed to be related to the chemicals.
But ADL was able to have the ban temporarily overturned by Middlesex Superior Court Judge Joseph Mitchell in April. A court trial on the ban was set for next week but has been moved to July 16. There is talk, however, of some kind of out-of-court settlement. ''Deliberations are supposedly going on between the attorneys,'' says Cambridge Mayor Leonard J. Russell.
Beltis works with small quantities of a number of highly toxic materials, including the DOD weapons-grade chemicals. To him, working with these chemicals is a matter of following standard safety procedures - wearing the right protective clothing, keeping decontaminating solutions handy, always working with a partner when handling the chemicals. He says he has no qualms about the work he is doing or the chemicals he is working with.
''Since we're not using them as a specific mode to warfare at this point,'' he says, ''. . . we have no fear assigned to them.''
Francis Duehay does. ''The evidence that I have from the Department of Defense Field Manual (on Military Chemistry and Chemical Compounds) is that it is sheer lunacy for that company to be testing that material in a high-density center,'' he says.
The chemicals are insidious. According to the DOD field manual, a very small dose of the colorless chemical Sarin is said to kill within 15 minutes of contact on the skin. The other two nerve agents ADL is working with have similar or higher toxicity. The two blister (mustard-gas) agents are less toxic.
ADL insists the laboratory - newly designed for toxic-chemical research - is safe. It boasts of ''state-of-the-art'' facilities, with sophisticated air-exhaust and waste-water treatment systems, alarms, high security, and double-lock doors, the company says.
ADL staff representitives point out that the Levins Laboratory was inspected by the Department of Defense, the Massachusetts Department of Public Health, two private consultants, and the civil defense departments of the three adjacent communities - Cambridge, Arlington, and Belmont.
Only the policymakers of the cities were left out of the initial inspection process. It was ADL's ability to keep the research secret that exacerbated city councilors, according to Mayor Russell. ''It was the secrecy that was involved that was maddening. This had a negative effect on the council.''
ADL senior vice-president D. Reid Wheedon Jr. defends the initial secrecy surrounding the project: ''We informed the safety officials (in Cambridge, Arlington, and Belmont), but we agreed this was not something we would tell the government officials,'' he says. ''In Arlington, the safety officials decided they should tell the selectmen and the city management. That's how the word got out.''
He says he doesn't feel there was anything wrong with the way the company handled this, that ADL was ''already bending over backwards to do more than the law required.'' (ADL was not required by law to submit to state or local inspections, Mr. Wheedon says.)
ADL was able to win the temporary injunction against the ban by arguing in an April 26 hearing that, under the Supremacy Clause of the United States Constitution (federal laws take precedent over state and local laws), the city of Cambridge had no power to overrule a congressionally mandated, government-sponsored project.
It's not clear whether the same argument could have been applied if there had been comprehensive regulations on toxic-chemical use in the first place. The ADL affidavit for the April 26 hearing alludes to the city's ''inconsistent'' toxic-chemical regulations.
Duehay is one councilor who wishes the city had had some clearer toxic-chemical laws. ''We were terribly embarrassed . . . not to have had any kind of regulations (on toxic chemicals). That will come up in the City Council within the next couple of weeks.''
Cambridge officials are not alone in their fight to ban local chemical-weapons research. Peggy Erickson, president of Concerned Citizens and Scientists for a Healthful Environment in Gaithersburg, Md., says Geomet Inc. is conducting similar research there. About a year ago, her environmental group learned the company was working with nerve-gas agents within 600 feet of an elementary school. Currently the school is closed for renovations, she says.
''We're going to work within the system, but if the (Geomet) work continues, we're not going to let our children back in school.''