Windshield washer fluid

Windshield washer fluid (also called windshield wiper fluid, wiper fluid, or screen wash) is a fluid for motor vehicles that is used in cleaning the windshield while the vehicle is being driven.

Delivery system

A control within the car can be operated to squirt fluid onto the windshield - typically using an electrical pump via jets mounted either beneath the windshield or beneath the wiper blade(s). The windshield wipers are then turned on cleaning dirt and debris off the windshield. As the fluid is depleted, water can be used to refill the fluid reservoir. Some vehicles use the same method to clean the rear window or the headlights also.

Washer fluid may sometimes be preheated before being delivered onto the windshield. This is especially desired in colder climates where a thin layer of ice or frost accumulates on the windshield's surface, eliminating the need to manually scrape the windshield or pour warm water on the glass. Although there are a few aftermarket preheat devices, General Motors has begun equipping vehicles with heated washer fluid systems from the factory beginning in 2006 with the Buick Lucerne sedan. The system, designed and manufactured by Microheat, emits a fine mist of superheated water that clears frost without damaging the windshield itself. GM also claims heated washer fluid helps in removing bug splatters and other road accumulation.

Varieties

The fluid comes in many forms and may require dilution before being applied, although many solutions available in the United States come premixed with no diluting required. Dilution factors will vary depending on season, for example, in winter the dilution factor may be 1:1, whereas during summer the dilution factor may be 1:10.

Several types of fluids are available on the market such as ready-made fluid, which is used 'neat' or as-is and sachet of crystals, which is also diluted with water. Anti-freeze, or methylated spirits, may be added to a mixture to give the product a lower freezing temperature. But, methanol is harmful when breathed in, so more popular now is an ethanol winter mix, e.g. PAV, water, ethanol (or isopropanol), and ethylene glycol.

Critical views

For a seemingly innocuous substance, windshield washer fluid is a subject of debate. Although all parties agree that the fluid is essential to safe driving, not all agree about what ingredients should comprise the fluid. Debate generally falls into two categories. First, there are those who are concerned about the environmental aspects of washer fluid. These people view the widespread, ground-level use of wiper fluid (amounting to billions of liters each year) can lead to a cumulative air pollution and to water pollution.

A second group of critics are composed of consumer advocacy groups and auto enthusiasts, who believe that the alcohols and solvents present in some, but not all, windshield washer fluid can damage the vehicle. These critics point to the corrosive effects of alcohol, methanol, and other components, with regard to paint, rubber, car wax, and plastics. These groups propose various alternatives and homemade recipes so as to protect the finish and mechanics of the motor vehicle.

Indeed, these critical views of windshield washer fluid have attracted the attention of scientists, governments, non-governmental organizations, and corporations. Of particular concern are volatile organic compounds. One study notes:

The potential for methanol emissions from the use of windshield washer fluid to contribute significantly to the formation of ground-level ozone in Canada is assessed. Reactivity and plausible chemical mechanisms for ozone formation are discussed. Assuming an environmental half-life of methanol of one month, a significant amount of these methanol emissions could participate in ozone formation. Options for reducing methanol emissions from this source were investigated in consultation with industry stakeholders. Recommendations included seasonal conversion to summer formulations, limiting methanol content, modifying OEM practices, and investigating more efficient fluid delivery system. [Carriere et al.] .

A Japanese research team has raised concerns about concrete and washer fluid:

A new phenomenon of decalcification of the cement concrete structure and dissolution of bitumen in bituminous pavement is described, caused by the surfactants included in the windshield washer fluid of automobiles. Decalcification occurs in cement concrete samples in the laboratory even at low concentrations of surfactant of 25 ppm. Recently, foam with fine bubbles have been observed in the water on pavement just after rain worldwide. The decalcification reaction was identified as an ion exchange reaction between the calcium ions Ca2+ in the concrete and Na+ in the surfactants using the electron spectroscopy for chemical analysis (ESCA) method. Bitumen was also found in the decalcified cement concrete, from which the Ca component had dissolved out gradually with time. [Moriyoshi et al.]

The Japanese study raises the specter of increased infrastructure costs, declines in road safety, and higher vehicle maintenance costs.

The critical views of windshield washer fluid take issue not with the substance in its ordinary form--which is rather mild--but rather consider the cumulative impact of billions of liters dumped into air, water, and concrete.

Other critics have expressed concern about the health impacts on humans. For example, some are concerned that a common ingredient, ethylene glycol, is a poison that can cause neurological effects, organ failure and death.

References

* Alain Carriere, C. Kaufmann; J. Shapiro, P. Paine, John H. Prinsen. "The Contribution of Methanol (Voc) Emissions From Windshield Washer Fluid Use to the Formation of Ground-Level Ozone." "SAE Transactions: Journal of Materials & Manufacturing." Vol. 109, pp. 227-234. 2000. [http://www.sae.org/technical/papers/2000-01-0663]

* A. Moriyoshi, M. Tabata, H. Kitagawa, K. Tokumitsu, N. Saeki. "Decalcification of cement concrete structures and dissolution of bitumen by windshield washer fluid." "JOURNAL OF THE JAPAN PETROLEUM INSTITUTE," vol.45 (2),pp.84-88, 2002.

ee also

* Antifreeze
*Chong, C; Hamersma, B. "Automobile radiator antifreeze and windshield washer fluid as IBA carriers for rooting woody cuttings." "HortScience," 30 (2) pp. 363-365, 1995.
* [http://www.floras-hideout.com/recipes/recipes.php?page=recipes&data=t-z/Windshield_Washer_Fluid Recipe for homemade washer fluid]