Cold Cleaning

Cold solvent cleaning is a process used to remove grease, wax and other impurities from metal and other parts. The process is also called degreasing or parts washing. Cleaning usually takes place in a small vat where mineral spirits or other solvents are sprayed onto the dirty part and it is brushed clean. (Note: "Wipe cleaning," which is the process of cleaning parts by simply wiping them with a cloth, is not considered cold solvent cleaning.) The solvent, which contains volatile organic materials (VOM), evaporates and can contribute to ground-level ozone (smog).

Cold cleaning takes place at auto repair shops, car dealerships, machine shops and other metal fabrication and manufacturing businesses.

The Illinois EPA changed the cold cleaning rule to reduce VOM emissions in the Chicago ozone nonattainment area (Cook, DuPage, Kane, Lake, McHenry and Will counties, Aux Sable Township and Goose Lake Township in Grundy County and Oswego Township in Kendall County) and the East St. Louis ozone nonattainment area (Madison, Monroe and St. Clair counties),which experience excess levels of smog. The new rule should reduce these ozone-producing VOM emissions from cold cleaning operations by about 67 percent.

The revisions require cold cleaning operations to use solvents having a vapor pressure of 2 millimeters or less of mercury by March 15, 1999, and 1 millimeter or less by March 15, 2001. Vapor pressure determines how quickly a liquid will evaporate — the lower the vapor pressure, the slower the evaporation. Vapor pressure is measured at 20 degrees Celsius (68 degrees Fahrenheit). A solvent’s vapor pressure is usually included on its Material Safety Data Sheet or can be obtained from the supplier.

In addition to using solvents that comply with vapor pressure limits, small businesses must maintain solvent purchase records that include the name of the supplier, date of purchase, total quantity purchased and vapor pressure of the solvent.

The solvent supplier must maintain records of the solvent’s purchaser, the date of purchase, the type of solvent, the amount purchased, the unit quantity (container size) purchased and the vapor pressure. Suppliers do not need to keep records for sales of unit quantities of five gallons or less.

The rule limits the sale and use of solvents used in all cold cleaning operations, except for those used to clean electronic components, in the Chicago and the East St. Louis ozone nonattainment areas.

Paint gun cleaning at automobile refinishing operations is not affected by this revision to the cold cleaning regulation.

The revisions to the cold cleaning regulations will be phased in from March 1999 through March 2001. Cold cleaning solvents with a vapor pressure of 2 or less must be in use by March 15, 1999, and solvents with a vapor pressure of 1 or less must be in use by March 15, 2001.

Ask your supplier if you are buying a solvent with a vapor pressure of 2 mm or less of mercury (1 mm or less after March 2001) and do not use a solvent with a vapor pressure of more than 2 mm of mercury after March 1999 and with a vapor pressure of more than 1 mm of mercury after March 2001.