There have been threads before wherein builders shied away from organic solvents like acetone, MEK and xylene in favor of lacquer thinner for dealing with unreacted epoxy. Some folks seem to think that lacquer thinner is safer. A quick Google search this morning revealed the following:

AWC Lacquer Thinner is composed of Toluene, Methyl Ethyl Ketone, and Methyl Isobutyl Ketone. (http://www.automagic.com/MSDS/24-msds.htm)

Flo-Strip Lacquer Thinner 1 is composed of Methyl Benzene, Isopropanol, 2-Propanone, 2-Butanone, Methyl Isobutyl Ketone, and 2 Butoxyethanol. (http://www.flo-strip.com/images/lt1.pdf)

Flo-Strip Lacquer Thinner 2 is composed of Methyl Benzene, Isopropanol, Xylene, Butyl Acetate, and 2-Butoxyethanol. (http://www.flo-strip.com/images/lt2.pdf)

Dura Technologies Lacquer Thinner is composed of Styrene, Methyl Ethyl Ketone, and Xylene. (http://www.duratec1.com/pdf/602-021.pdf)

Allpro Lacquer Thinner is composed of Methyl Ethyl Ketone, N-Heptane, Methylcyclohexane, Toluene, Cyclohexane, C6-C8 Paraffins and Cycloparaffins, Methanol, Propylene Glycol Monoethyl, Ether Acetate, Toluene, Xylene, Ethyl Benzene, Acetone, and Ethyl Acetate. (http://www.allprocorp.com/msds/Klean/LacThinWEB.cfm)

Lenmar, Inc. Lacquer Thinner is composed of Acetone, Methyl Isobutyl Ketone, Ethylene Glycol Monobutyl Ether, Heptane, Isopropanol, Methanol, and Toluene. (http://www.allprocorp.com/msds/Coronado/LACQTHINNER.cfm)

It would appear that there is no industry-wide definition of what "lacquer thinner" is. It is clear that they are blends of hazardous organic solvents, that the blend will vary from one manufacturer to another, and that they are not safer than generic organic solvents. So how do you know what is really in the can at the hardware store? The presence of paraffins in Allpro is of great concern, since they are bond breakers. Looks to me like "lacquer thinner" is whatever is left in the tank after they boil off the good stuff.

My advice is to use straight isopropyl alcohol (isopropanol, or rubbing alcohol) from the drug store, about $1 for a quart. It works as well as more exotic compounds, is more benign, easily available and cheaper as well.