HELENA -- A television commercial slamming Sen. Conrad Burns for cursing at a firefighting crew could be too vulgar for broadcast television, the Montana Broadcasters Association is warning its members.

Citing the Federal Communications Commission's ''current stance on indecent language,'' association President Greg MacDonald advised stations Wednesday to pull the spot or check with attorneys before airing it.

''While we have no idea how the commission might come down on such language in a political spot, we also don't want to test the waters at $325,000 per violation,'' MacDonald wrote.

The commercial, paid for by the Democratic Senate Campaign Committee, opens with a cautionary note: ''The following contains language by Conrad Burns unsuitable for Montana.''

The narrator begins by praising firefighters as heroes, then switches to quotes from reports of a confrontation Burns had with firefighters in July while waiting for a flight at the Billings airport.

''But Conrad Burns said they had done, quote, 'a piss poor job,' and while pointing at one, 'he hasn't done a Goddamned thing,' '' the announcer says. The quotes are based on a report filed by a state official who was sent to the airport to talk with Burns after he confronted the Virginia firefighting team.

Burns later apologized for the comments, saying he was expressing the frustration of ranchers who were critical of the way the firefighting efforts had been handled.

MacDonald said he issued the e-mail after one station alerted him to the content -- and questioned whether the station could be in trouble with the FCC because of the language.

Monty Wallis, general manager of KTVQ-TV in Billings and vice president of Cordillera Communications in Montana, said Wednesday he was not amused by the ad's language and was ''absolutely appalled'' anyone would think it was appropriate to air. His station aired it once Wednesday morning, unaware of the language, he said.

''I know it's the campaign season and we see all kinds of ads ... but I wasn't happy about it at all and I pulled it instantly,'' he said. ''It was certainly inappropriate and did not belong on the air.''

The Democratic Senate Campaign Committee said voters need to know what Burns said.

''Montanans want a senator they can be proud of, not a walking blooper,'' DSCC spokesman Phil Singer said.

Singer would not say how long the commercial would run, nor how much was being spent on it, but that it was running in major markets in Montana and that the cost was ''substantial.''

Burns is locked in a tough race with challenger Jon Tester, and attack advertisements from both sides have been filling the airwaves in Montana.

The Burns campaign said it expects the ads to get worse.

''Montana can expect more of the name calling and mud slinging from the national Democratic Party,'' said spokesman Jason Klindt.