Denatured alcohol (DA) is safe to use for the cleaning of most plastic, aluminum, stainless steel, nickel-plated, and anodized windshield repair injectors. DA evaporates very quickly, so if possible, use only DA to clean Delta Kits windshield repair resin injectors.
It is also a better choice than pure ethanol because it is considerably less expensive, and a better choice than Isopropyl alcohol which contains 10%-30% water and does not dry as quickly as DA.
DA is basically ethanol with one or more added chemicals to render in unfit for human consumption. While those chemicals vary, the typical DA that you find at your local hardware and paint stores has methyl alcohol (methanol) added. The primary alcohol used in alcoholic beverages is ethanol. DA often is a mixture of about 90% pure ethanol and 10% toxic denaturants.
Use isopropyl alcohol in most of the same applications as denatured alcohol.
Compared to DA, Isopropyl alcohol is a better cleaning agent especially for electronics but it contains water so it does not evaporate quite as quickly. Therefore, if you use Isopropyl alcohol to clean your Delta Kits injectors, be aware that additional dry time will be necessary between cleaning and reuse. That extra dry time is the only reason Delta Kits recommends DA over Isopropyl alcohol. Note: Blowing out the injector with compressed air after cleaning in either DA or Isopropyl alcohol significantly reduces dry time.
Caution: As with any industrial cleaner or solvent, wear chemical resistant gloves and eyewear when using DA or Isopropyl alcohol.
Update from September 2009 article.