Since no else mentioned it, SNOW is also very good for cleaning your windshield. I think you have plenty of that in Alaska.
it’s a good question to ask, but…
the alcohol is going to evaporate. or it’s going to dilute incredibly. i don’t think the 2 gallons a year per car is going to matter.
As mentioned most alcohols evaporate very quickly, which is why they help reduce streaking on glass.
ACCORDING TO THE EPA, methanol is not very toxic in the environment because it evaporated quickly in air, and also because plants and animals don’t store the chemical.
ACCORDING TO TOXNET, methanol begins to be toxic to aquatic species around 1% or around 25mg/L, depending on the study.
http://toxnet.nlm.nih.gov/cgi-bin/sis/search/f?./temp/~JeLxXr:1
Typical wiper fluid is around 40% methanol, but after evaporation and dilution it would be hard to reach toxic concentration in a river or stream.
The biggest risk from the use of methanol is inhalation by the car occupant of the vapors when sprayed.
PEG-Alcohol would likely work. It is available in food grade and is used in many medicines like cough syrup.
The suggestion from latindaddy using glycine is great, but typically glycine is relatively expensive compared to the standard use of methanol and isopropanol. Glycine has limited availability since it is used in high value added products such as premium hand and body soap.
The reason companies don’t use ethyl alcohol is probably because you have to pay liquor tax on it unless it is denatured (not drinkable due to added poison). Industrial denatured alcohol has no specific definition which means there is a lot of variability and most formulations don’t have the ability to accept undefined liability.
I work for an alcohol burning fireplace company. There are many differences in alcohol.
The greenest alcohol is ethanol. Ethanol is basically like vodka or rum but it has added agents to make it undrinkable. It’s made from by-products of the agricultural industry. The greenest alcohol comes from the brewing industry. This is what they add to gasoline. The by-product of ethanol is steam and carbon dioxide.
Isopropyl alcohol is made from fossil fuels. When you burn it, it releases carbon monoxide.
Methanol is made from wood pulp. It is highly poisonous to drink because the liquid becomes poisonous during fermentation.
You wouldn’t really want to drink any of them, but if you have to use it, it’s best to use ethanol. Or really cheap vodka!
Hope this helps!
The only way you’ll ever keep things from freezing in Alaska or any other cold place is to use a liquid that won’t freeze. The idea of using something that’d is kept inside the car where it is warm won’t work because as soon as the liquid hits the cold air and windshield it will freeze - been there, done that - pretty messy and hard to see through. Also, had a windshield washer once back in the early 60s that had a squeeze bottle under the dash. It worked but didn’t hold too much liquid.
Years ago in Winnipeg, Manitoba (much like Alaska in winter!) my 62 Fairlane did not have a windshield washer. Thus…when the windows were dirty I would pull out a plastic dishwashing bottle filled with window cleaner, roll down the window, reach around and squirt vigourously while also turning on the windshield wipers (usually at a stoplight). This worked fine (though chilly at times) and if I forgot to take the bottle in at night…well, I remembered the next night.
100 proof vodka freezes at approx. -40F. Sometimes you can find even the “high test” stuff fairly cheap. I’ve used it for cleaning when I’ve run out of Isopropyl ! You might want to give it a try in milder weather. I do my own mix with 50% Iso, 45% water and 5% pine cleaner. Freezing is not much of an issue for me, living in SoCal. When I hit the washer button my truck does smell a bit like a conifer daiquiri, but it works great!
At what concentration of ethanol to water is combustion a safety concern in an accident?
I think Scott has thought too highly of humans, worrying that we could possibly contaminate good 'ole Mother Earth with too many cars (especially in Alaska!) spritzing windshield washer fluid. There’s not one salmon that would ever notice or care.
Bobwiggins and Jimc, (caps MINE) DON"T USE PROPYLENE GLYCOL!!! The stuff used in heating systems is mostly sugar and will leave one heck of a mess on your car AND your windshield.
The reason they use it on planes is its ability to NOT pollute (food grade), but also because it holds on to the surfaces of the plane until the freezing danger gets well below the craft.(over the water/ice producing clouds).JCA
RonG July 18
You might be interested to know that the German Me109 used GASOLINE as a windscreen de-icer. (for the kids, this was a WW2 fighter aircraft)
The reason they use [propylene glycol] on planes is its ability to NOT pollute (food grade), but also because it holds on to the surfaces of the plane until the freezing danger gets well below the craft.(over the water/ice producing clouds).The vast majority of propylene glycol used to deice aircraft is type I deicing fluid, and it does not stick to the surface of the aircraft. Types II, III, and IV have additives that cause them to stick, to some degree, to the wings to act as an anti-icer. More than 75% of deicing fluid used is regular type I. It is a deicer only, not an anti-icing fluid. All you really need it for is to knock the ice off long enough to get airborne. Once in the air, bleed air from the turbines flows through the leading edge of the wing to prevent ice from forming.
What about using a green soap and a fish tank heater/trough heater?
That would keep the water from freezing.
All this concern about an eco-friendly washer fluid sounds well intentioned, but let’s get real. There is hardly a single thing about cars that isn’t already disastrous for the environment. The pollutants that come out of the exhaust pipe get into our environment just as the washer fluid does into the salmon’s. Do we care about that? Add to the cocktail the motor oil and other fluids and the chemicals and hazardous materials used in automobile manufacture itself, and a spritz of washer fluid is nothing. I’m with Johnnybuzzkill. If not polluting is important, don’t drive.
Just buy the washer fluid that’s good to -40 and maybe add a battery blanket to your fluid bin and get a 4-way so when you plug in you can keep the fluid warm 
get a 4-way so when you plug in you can keep the fluid warm
When I heard the question about eco-friendly washer fluid, I was reminded of the following story from Paul Harvey’s “The Rest of the Story”. The bottom line solution has already been given by several readers, but here’s the story …
"Siberian Chill-Chaser
The ultimate geographical metaphor for cold is Siberia.
How cold is it? It’s so cold that railroad tracks and tree branches frequently snap off like candy canes.
It’s so cold that atmospheric ice crystals sometimes blot out the sun, turning the day to night.
It’s so cold that a standard facet of infant education is to breathe only through the nose.
It’s so cold that not even a virus can survive in some regions.
It’s so cold that the slightest breeze can freeze your face.
And it’s so cold that should you fall through the ice on a pond or a river and leap out of the water to keep from drowning, you would be killed instantly, fresh frozen like a package of Birds Eye peas.
That’s how cold it can get in Siberia.
People adapt.
Evan at sixty below zero the children still walk to school and the miners still mine and the construction workers continue to work. Life goes on. People adapt.
But wait a minute. Native Siberians are faced with a challenge in addition to that of their own biological adjustment.
There are the myriad technical difficulties often beyond their control. Most of the construction equipment is certified by the manufacturer only to forty degrees below zero. At fifty below, electric welding apparatus ceases to function. Period.
For while people adapt, machinery cannot.
That means the people must apply their resourcefulness to their machines; they must use their archetypical ingenuity to solve technological dilemmas rarely encountered by the rest of the world.
In the area of automotives the Siberians have made a discovery which might even benefit your car, in the event of another arctic winter.
It concerns hydraulic systems-brakes in particular. And this Siberian Chill-Chaser is THE REST OF THE STORY.
The cold weather maintenance of their automobiles is of increasing concern to North Americans.
The fact is that most cars have problems at temperatures below zero Fahrenheit. At twenty below and below, no car is impervious to mechanical difficulty.
For counsel, under these frigid circumstances, American car owners are turning to their northern neighbors in Wisconsin and in Minnesota, to people who deal with this inclement climate inconvenience every winter.
As any year round resident of Green Bay, Wisconsin, can tell you, there is an engine block heater on the market. You park somewhere, you plug this heater in as a matter of routine.
There is also a portable battery charger which operates on a 110 house current. Another must.
But what do you do when it’s so cold that your car’s hydraulic brake system is threatened?
In Siberia, where even the slightest breeze can freeze your face, the natives have discovered a brake fluid additive. An extremely cold resistant something which invariably laughs in the face of Old Man Winter.
Keeps the people happy too. Vodka. "
I had the same thought of another user… use VODKA to clean the glass… it doesn’t freeze…