The ongoing war of words between Fairfax County political opponents John F. Herrity and Audrey Moore, candidates for chairman of the Board of Supervisors, erupted yesterday with the nastiest salvos of the election season.

Herrity, the Republican incumbent, charged Moore's campaign with being "sleazy," and Moore, a Democratic supervisor from the Annandale District, countered by saying her opponent had distributed misleading campaign literature.

In addition, Moore criticized the fact that mailing labels supplied by the county school system were used by the Fairfax County Retired Teachers Association to send letters praising Herrity to retired school teachers. Moore said it was an inappropriate use of county materials for political purposes.

James Swinson, chairman of the county Republican Party, called Moore a "hypocrite," saying she had used her county supervisor office funds to mail campaign literature.

Herrity, who has championed economic development in the county since his election to the board in 1972, is being challenged in the Nov. 3 election by Moore, who for more than a decade has tried to thwart the county's booming growth.

In addition to being the most costly election battle ever waged in suburban Washington, the race is expected by some political observers to be unusually mean-spirited.

Although observers anticipated the most explosive issues to be related to development and the county's traffic problems, the dispute that broke out yesterday involved a series of letters mailed to retired county employes by Herrity's campaign, Moore and the Fairfax County Retired Teachers Association.

The genesis was a June 22 mailing by the retired teachers group that praised Herrity's role in increasing the county's contribution to health benefits for retired county employes. Mailing labels for retired teachers were supplied by the county school system.

Two weeks later, Herrity's campaign mailed a letter to another group of retired county employes saying the increased benefits came "thanks to Jack's efforts." Included was a request to make a donation to his campaign. Addresses for this mailing came from the county Office of Personnel.

After Herrity's letter was sent, Moore complained to county officials that Herrity had received a mailing list from the county, and she asked for a copy. She then mailed a letter of her own, saying that credit for increased health benefits "goes not to us who represented the county Board of Supervisors, but to members of the negotiating team of the Employees Advisory Council," who helped hammer out the new benefits.

Moore said yesterday her letter was typed on her supervisor letterhead and was paid for "by the taxpayers," not her campaign.

According to Moore, the mailings by the Retired Teachers Association and Herrity's campaign were both misleading because they gave Herrity the lion's share of credit for the increased health benefits, "and that's not true."

"I was responding to something he had no business sending out," Moore said, adding that she had made "perfectly legitimate" use of supervisor funds.

"This is a sleazy operation," Herrity said of Moore's challenge of the Retired Teachers Association mailing. "I appreciate it when any organization is going to give me credit for something I did, and for Audrey Moore to try to take the credit away from me by slamming the school system for giving them the mailing {labels} is hogwash."

Herrity would not comment on Moore's use of county funds to pay for her mailing, referring questions to Swinson, who said that Herrity's "This is a sleazy operation."

-- John F. Herrity

mailing "went out as a political piece, paid for by his campaign . . . . If she put out a letter in response to his letter, that makes it political right there."

According to Jean Leer, president of the 590-member Retired Teachers Association, the letter they sent about Herrity was included in a mailing urging retired county teachers to join her organization.

Leer said the Herrity letter was sent in the same envelopes as the recruiting letter to save postage and "to let members know that we were doing things" to obtain better health benefits. She said the Retired Teachers Association is nonpartisan.

On Tuesday, the organization sent a follow-up letter stating: "In fairness to other supervisors, it should be noted that the {increase} conformed to the recommendation of a subcommittee of the board that had been studying this issue for several months." The letter added that the school system "had no knowledge" that the letter about Herrity would be included in the mailing.

Fairfax County School Superintendent Robert R. Spillane said school officials had requested the second letter because "it did appear that some of the material {in the first mailing} could have appeared as an endorsement."

Spillane said that, at least through the election and possibly after, school officials will insist on seeing materials that are sent with school system labels.