My grade in Organic Chemistry II was a D, so take that into account re this advice. Rubbing alcohol - isopropanol - affects quite a few chemicals. What material is your shirt? If cotton, should be no adverse reaction if you soak the area of impact with isopropanol for about 30 minutes. First test this treatment on an area of the shirt that is not visible when you are wearing it. Then rinse the shirt thoroughly in water. In fact, after the isopropanol I would soak the shirt in dishwashing detergent. After the rinse, wash the shirt as you normally would. I would let the shirt air dry, because tossing it in a dryer could set the residue.

Good luck!