Here's what I found posted on Simple Green's Website under FAQ.
You can come to your own conclussions base on the Simple Green Formulation that you are using. (Yes, there are different formulations)
From the Website:
"Aircraft Cleaning – Is Simple Green® safe for cleaning aircraft?
Simple Green manufactures products specifically designed for use on aircraft. Products available on the market are Extreme Simple Green® Aircraft & Precision Cleaner and Simple Green® Pro HD. These products were initially developed for the aircraft industry and extensive testing shows that they are safe for use on aluminum, plastics, rubbers and high tech alloys, even in the most extreme circumstances. These products conform to both Boeing D6-17487P spec for general aircraft exterior cleaning and Pratt & Whitney PWA 36604revC spec for aircraft engine cleaning.
Alkaline Aqueous Solution – What is an alkaline aqueous solution?
Alkaline aqueous solutions are water-based mixtures with a pH greater than 7. Most of these types of cleaners range from a pH of 10 to 14. Simple Green® is a water-based cleaner with a pH of 9.3 to 9.5. Alkaline aqueous solutions are the most common solutions in water based cleaning. These often contain additives to improve cleaning, such as sequestering agents, emulsifiers and surfactants. Corrosion inhibitors may be necessary with some metals, especially aluminum.
Alkaline aqueous solutions remove grease, coolants, cutting oils, shop dirt, fingerprints, cosmoline, petrolatum and some water-soluble paints. They are also used with all types of liquid processes, e.g., sprays, ultrasonic, immersion and power washers. These solutions can clean to very high levels, with good filtration and rinsing. Cost per gallon is generally less than for semi-aqueous cleaners.
One should never assume that aqueous solutions can be disposed of down the drain. Your local water treatment authority or publicly owned treatment works (POTW) will have information on treatment and disposal of these cleaners. Adjustment of pH and dilution are usually required before disposal to a drain.
Aluminum - Is it safe to use Simple Green® on aluminum?
When used with caution and according to the instructions, Simple Green All-Purpose Cleaner has been safely and successfully used to clean aluminum. Simple Green All-Purpose Cleaner, Crystal Simple Green® Cleaner/Degreaser, Simple Green Pressure Washer Concentrates, and Pro Series™ Simple Green® Automotive Cleaner have been used on aircraft, automotive, industrial and consumer aluminum items for over 20 years. However, caution and common sense must be used: aluminum is a soft metal that easily corrodes with unprotected exposure to water. The aqueous-base and alkalinity of Simple Green All-Purpose Cleaner can accelerate the corrosion process. Therefore, contact times for unprotected or unpainted aluminum surfaces should be kept as brief as the job will allow - never for more than 10 minutes. Large cleaning jobs should be conducted in smaller-area stages to achieve lower contact time. Rinsing after cleaning should always be extremely thorough - paying special attention to flush out cracks and crevices to remove all Simple Green® product residues. Unfinished, uncoated or unpainted aluminum cleaned with Simple Green products should receive some sort of protectant after cleaning to prevent oxidation.
Simple Green has also developed break-through water based cleaners that are safe for use on metals, plastics, rubber and high tech alloys. Extreme Simple Green® Aircraft & Precision Cleaner and Simple Green® Pro HD are available on both the industrial and retail markets, respectively. These products were initially developed for the aircraft industry and extensive testing shows that they are safe and effective on a variety of metals and other sensitive surfaces even in the most extreme circumstances.
Simple Green® Stainless Steel One Step Cleaner & Polish is another option for cleaning polished aluminum. This product is designed for light duty metal cleaning and polishing. "
I know, I know, this subject has been around and around. Would I use it? NO!:soscared:
I have the Extreme formulation from Sam's Club I use to clean wash mitts and towels and an ocassional rug/carpet that have oil or grease on them. But based on the information above, I'd be leary about using it on aluminum wheels or as an engine cleaner.
You can come to your own conclussions base on the Simple Green Formulation that you are using. (Yes, there are different formulations)
From the Website:
"Aircraft Cleaning – Is Simple Green® safe for cleaning aircraft?
Simple Green manufactures products specifically designed for use on aircraft. Products available on the market are Extreme Simple Green® Aircraft & Precision Cleaner and Simple Green® Pro HD. These products were initially developed for the aircraft industry and extensive testing shows that they are safe for use on aluminum, plastics, rubbers and high tech alloys, even in the most extreme circumstances. These products conform to both Boeing D6-17487P spec for general aircraft exterior cleaning and Pratt & Whitney PWA 36604revC spec for aircraft engine cleaning.
Alkaline Aqueous Solution – What is an alkaline aqueous solution?
Alkaline aqueous solutions are water-based mixtures with a pH greater than 7. Most of these types of cleaners range from a pH of 10 to 14. Simple Green® is a water-based cleaner with a pH of 9.3 to 9.5. Alkaline aqueous solutions are the most common solutions in water based cleaning. These often contain additives to improve cleaning, such as sequestering agents, emulsifiers and surfactants. Corrosion inhibitors may be necessary with some metals, especially aluminum.
Alkaline aqueous solutions remove grease, coolants, cutting oils, shop dirt, fingerprints, cosmoline, petrolatum and some water-soluble paints. They are also used with all types of liquid processes, e.g., sprays, ultrasonic, immersion and power washers. These solutions can clean to very high levels, with good filtration and rinsing. Cost per gallon is generally less than for semi-aqueous cleaners.
One should never assume that aqueous solutions can be disposed of down the drain. Your local water treatment authority or publicly owned treatment works (POTW) will have information on treatment and disposal of these cleaners. Adjustment of pH and dilution are usually required before disposal to a drain.
Aluminum - Is it safe to use Simple Green® on aluminum?
When used with caution and according to the instructions, Simple Green All-Purpose Cleaner has been safely and successfully used to clean aluminum. Simple Green All-Purpose Cleaner, Crystal Simple Green® Cleaner/Degreaser, Simple Green Pressure Washer Concentrates, and Pro Series™ Simple Green® Automotive Cleaner have been used on aircraft, automotive, industrial and consumer aluminum items for over 20 years. However, caution and common sense must be used: aluminum is a soft metal that easily corrodes with unprotected exposure to water. The aqueous-base and alkalinity of Simple Green All-Purpose Cleaner can accelerate the corrosion process. Therefore, contact times for unprotected or unpainted aluminum surfaces should be kept as brief as the job will allow - never for more than 10 minutes. Large cleaning jobs should be conducted in smaller-area stages to achieve lower contact time. Rinsing after cleaning should always be extremely thorough - paying special attention to flush out cracks and crevices to remove all Simple Green® product residues. Unfinished, uncoated or unpainted aluminum cleaned with Simple Green products should receive some sort of protectant after cleaning to prevent oxidation.
Simple Green has also developed break-through water based cleaners that are safe for use on metals, plastics, rubber and high tech alloys. Extreme Simple Green® Aircraft & Precision Cleaner and Simple Green® Pro HD are available on both the industrial and retail markets, respectively. These products were initially developed for the aircraft industry and extensive testing shows that they are safe and effective on a variety of metals and other sensitive surfaces even in the most extreme circumstances.
Simple Green® Stainless Steel One Step Cleaner & Polish is another option for cleaning polished aluminum. This product is designed for light duty metal cleaning and polishing. "
I know, I know, this subject has been around and around. Would I use it? NO!:soscared:
I have the Extreme formulation from Sam's Club I use to clean wash mitts and towels and an ocassional rug/carpet that have oil or grease on them. But based on the information above, I'd be leary about using it on aluminum wheels or as an engine cleaner.