In dry cleaning there are three soil types: insoluble soil like lint and dust, solvent-soluble soil like oils and waxes, and water-soluble soil like sweat and juice. Remove them by using detergent in the wheel, filtering and distilling solvent, and pre-spotting water-based stains at the board.

Soil Types in Dry Cleaning: A Simple NCA Guide

Clothes pick up “soil” every day. Soil means any foreign matter on fabric. It can be dust, lint, oil, food, or color that rubbed off. If we do not control it, soil can build up in the system and settle back on clothes. The National Cleaners Association (NCA) teaches a simple way to think about soil so cleaners can remove it fast and keep garments bright.

1) Insoluble soil

This is dry dirt that does not mix with water or with the cleaning liquid. Think of lint, dust, soot, and tiny broken fibers. In the machine, good movement and the right detergent help slide this dirt off. Strong filters catch the particles so they do not redeposit on the load. Regular maintenance keeps the filter doing its job.

2) Solvent-soluble soil

This soil mixes with the cleaning liquid. It comes from body oils, cooking grease, waxes, and some makeup. When too much oily soil is in the solvent, the liquid turns darker and can leave gray films on clothes. The fix is routine filtration and distillation to refresh the solvent. Many plants also use activated carbon or clay to pull out oils and color bodies so the solvent stays clear.

3) Water-soluble soil

This soil mixes with water, not with solvent. It includes sweat, juice, salt, and many food spills. Since the drycleaning bath has little or no water, these stains must be pre-treated at the spotting board before the load goes into the wheel. A quick pre-spot saves time and prevents set stains.

Keep the solvent clean

Watch for warning signs: cloudy sight glass, dark solvent, new odors, or a rise in static and redeposition. Run filters on schedule. Distill often enough for your load mix. Check separators and coils so water does not leak into the system. Train staff to pre-spot water-based stains and to use the correct detergent dosage.

Fast checklist

• Pre-spot water-based stains at the board

• Measure detergent in every load

• Change and monitor filters

• Distill solvent on a set schedule

• Inspect for water leaks and repair quickly

• Document results and adjust frequency as needed

Clean solvent plus smart pre-spotting leads to cleaner clothes, fewer re-cleans, and happier customers. For deeper training and certification, join the National Cleaners Association (NCA) and access member tools, classes, and support.

Mini-FAQ

What are the three soil types? Insoluble, solvent-soluble, and water-soluble.
Why does solvent turn dark? Oils and color bodies mix into it and need filtration and distillation.
Do water-based stains come out in the wheel? Not well. Pre-spot them with water-based agents first.