Concentrated formula designed to mix with water; no solvents are required to clean No-Toil treated air filters, Breaks down the waterproofing chemicals of the No-Toil filter oil and rim grease before completely washing the oil, grease, dust and dirt from the filter, Non-toxic, no-fume/no-odor cleaning solution is skin-safe, and can be used to clean filters in a bucket of water or the kitchen sink, It's biodegradable, so go ahead and dump the dirty solution right down the drain!