Acetone is included in "ER" to provide an aggressive, fast-acting solvent for caked powder residues. Because acetone is an aromatic,organic solvent, it is recommended that users leave it out if the cleaner will be used in enclosed spaces lacking forced air ventilation. The acetone in ER will evaporate, liberating volatile organic compounds (VOCs) into the atmosphere unless containers are kept tightly closed when not in use. The cleaner is still effective without the acetone, but it is not as "fast-acting."
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Wipe spilled Ed's Red from exterior surfaces before storing the gun. While Ed's Red is harmless to blue and nickel finishes, the acetone it contains is harmful to most wood finishes.