Denying professional firefighters had ever interfered with volunteers on their way to a fire call, Tony Pagano, president of Local 628 of the Professional Firefighters Association in Yonkers, said: ''In Yonkers, the most critical point in fighting fires is the response time. By the time the volunteers arrive, it's over 20 minutes, and lives can't wait 20 minutes.''

At the meeting, Mr. Pagano said that ''there was no recognition of volunteers among professional ranks,'' and he added, ''I will not stand next to a monument that has the name of any other than professionals, and my membership agrees.''

''I'm a trade unionist, and I have a family,'' Walter Ferguson, district representative of the New York State Professional Firefighters Association, added. ''If you act in a way that interferes with my ability to earn a living, I resent that.''

At a meeting earlier this spring, attended by 16 of the 18 Westchester chapters of his union, Mr. Ferguson said, the group had voted unanimously not to participate in the proposed memorial. ''The joint names did not sit well with the brothers, and they told me to get out,'' Mr. Ferguson said.

The Westchester Fallen Firefighters Memorial Monument Committee had representatives from the area's four leading firefighting organizations - both volunteer and professional groups. It had been working for three years to build a joint memorial to the 47 men killed fighting fires in the county since a record was first kept in l907. Twenty-five of the dead were volunteers, Ray Rush, the county's Fire Coordinator, said. Twenty-two were professionals. A Model of the Sculpture

The committee of volunteer and professional firemen had commissioned an eight-foot bronze sculpture of a fireman helping a comrade. They planned to display the statue at the Fire Training Center in Valhalla. They had already received a model of the proposed sculpture from the artist, Julia Balk, who created Westchester's Vietnam Veterans' Memorial now on view in Lasdon Park in Somers.

When the professional members on the committee announced they were withdrawing, Mr. O'Rourke offered to mediate. ''You've been candid and forthright,'' Mr. O'Rourke told the group gathered at the fire training center near the end of the meeting, which the County Executive conceded had been ''abrasive.''