costs about 6 times as much as sodium chloride. Other substances were used rarely and experimentally. Alternative substances (urea, alcohols, glycols) are often used at airports. In recent years, Geomelt, a combination of salt brine and beet juice that is otherwise considered a waste product has been used for pretreatment. In Wisconsin, USA, surplus brine from cheese making has been used for this purpose. Inert spreadings can be: sand brash, rubble, crushed slag, etc. slag wood ash (for household use only) sawdust The choice of treatment may include consideration of the effect on vegetation, pets and other animals, the local watershed, and effectiveness with regard to speed and temperature. Some chemicals can degrade concrete, metals, and other materials. The resulting meltwater and slush can cause frost heaving if it re-freezes, which can also damage pavement. Inert materials can damage vehicles and create dust. As an example, in the Czech Republic during the winter season of 2000/2001, net material expenditure for road treatment was: 168 000 tonnes of salt (mostly NaCl), 348 000 tonnes of sand and crushed stone and 91 000 tonnes of other materials like slag. In Ireland, the annual expenditure of salt was 30 000 tonnes. Switzerland reports their annual expenditure as 600 grammes of salt to every square metre of roads on average. Side effects De-icing chemicals and inert materials need to be selected and applied with care. Chemicals may react with infrastructure, the environment, and vehicles. Chlorides corrode steel and aluminum in reinforced concrete, structures and vehicles. Acetates can cause asphalt stripping, weakening the bond between asphalt binder and aggregate. Sand and grit can clog pavement joints and cracks, preventing pavement from expanding in the summer and increasing stress in the pavement. Salts can be toxic to plants and aquatic life, including the trees lining the side of the roads. Sand can alter aquatic habitats where roads are near streams and lakes. Acetates can reduce oxygen levels in smaller water bodies, stressing aquatic animal life. Sand can be ground by tires into very fine particulate matter and become airborne, contributing to air pollution. Snow removal tools Snow shovel Snow blower Snow Vacuum Snowplow Ice pick Skid-steer loader Spade Winter service vehicle Snowmelter Snowmelt system embedded in pavement, also known as radiant heat. See also Grit bin Ice road Metromelt Snow removal in Montreal Parking chair Road slipperiness Snow emergency Smart highway Snow chains Snow filtration Snowplow