(AP) - North Pole. Well-informed sources have it that Ole' St. Nick has been forced to replace his bright red uniform with a new one as a result of extensive soiling due to unusually dirty fireplaces this holiday season...

While we are sure that St. Nick's wardrobe is something that is of concern to many, there are other more critical reasons to keep one's fireplace and chimney clean and in tip top operating condition. In fact, a dirty chimney will not only diminish the effectiveness of a fireplace, but, with severe neglect, could be the reason for a chimney fire. And, chimney fires lead to house fires.

According to statistics published by the U.S. Consumer Product Safety Commission for 1988, 65,200 residential fires in the 50 states were related to chimneys, fireplaces, woodstoves and other solid fuel appliances. These are fires that may possibly have been prevented with regular chimney inspection, cleaning and repair.

The first step to having a healthy fireplace is by burning the right fuel. Never burn garbage, plastics, foil, coated paper, or painted or chemically treated scrap wood. In addition to causing an unfavorable build up on the interior of the firebox and chimney, these also produce noxious fumes which pollute the air (in & out of the home). Burn only seasoned split wood. Seasoning allows moisture in wood to evaporate. Forty-four per cent more heat can be generated from a seasoned log. A clean burning fire is a hotter fire with good drafting conditions that produce cleaner combustion and less smoke from the chimney.

The next step is to have your chimney inspected by a professional chimney sweep annually and, if necessary, cleaned of soot and creosote which is a chemical substance that forms when wood burns. It is the heavy creosote build up that becomes highly flammable often resulting in explosive chimney fires. According to the National Chimney Sweep Guild (NCSG), a national trade association for chimney sweeps, a visual inspection is all that is required for most chimneys. Whereas fees vary according to height and configuration of the fireplace, most visual inspections range from $35. to $60.

In the case where a visual inspection is not adequate, many chimney sweeps are now equipped to do more elaborate inspections with a video camera and monitor referred to as a "chimscan". The chimscan is more costly than the visual inspection ($100 to $200), but will reveal significantly better information about the condition of a chimney. This is especially important when the integrity of the flue is in question due to age or damage from an earthquake or chimney fire.

Finally, as part of his inspection and cleaning, the chimney sweep will also make comments relative to the condition and operation of the damper and spark arrester. Frequently, these will either not exist or are in such a state where they need replacement.

The damper is a steel or cast-iron door that opens or closes the throat of the firebox into the flue. It regulates draft and prevents the loss of heat up the chimney. The spark arrester is a cage-like device which is secured to the top of the chimney. It prevents sparks and ash from escaping and causing a fire on the roof or other potentially flammable substance. It will also keep squirrels, birds and raccoons from nesting in the chimney. Nesting materials can cause a serious safety hazard. Their droppings pose health risks because diseases may be transmitted through their fecal materials. A spark arrester will prevent this.

Prices for a standard cleaning range from $50 to $100 for a single story home and between $75. and $125. for a two story home.