Fairfax County residents will have a chance to testify on two versions of a proposed ordinance prohibiting the sale of pornographic material to persons under 18. The Board of Supervisors voted this week to authorize the advertisement of a public hearing, which is scheduled for Sept. 19.

The two versions proposed by board chairman John F. Herrity and supervisor Alan Magazine differ only in the manner of display of "graphic pictorial" material eachwould permit. The ordinance is aimed at restricting the sale of soft-core material, specifically magazines currently on sale in many retail stores throughout the county.

Herrity's proposal would require that such material be kept behind sales counters, while Magazine's proposal requires that copies be individually wrapped in opaque covering and displayed so that only the title is visible.

Under both proposals maximum penalties for sale of material to juveniles would be a one-year jail term and/or a fine of $1,000.

Magazine said that while he favored controls over so-called "girlie magazines" he feared that any ordinance not narrowly defined might prove unenforceable. "What do you do about a book with a plain cover which had scenes from a movie" which may be deemed pornographic, he ssaid.

Magazine also expressed reservations about the possible scope of an ordinance that would empower police to make individual determinations about whether material is pornographic. "My concern is that we are leaving it up to the police to make a determination about whether something appeals to 'prurient, morbid or shameful interests.' I don't see how you can train anybody when it comes to a philosophical issue," he said.

"I'd like to see a definition of the kinds of material we're concerned about," Magazine concluded. James P. Downey, assistant county attorney who reviewed the two versions of the proposed ordinance, said, however, that a narrow definition was probablyno possible.