An information sheet from Ineos Nova lists various solvents such as cyclohexanone, cyclohexanone/tetrahydrofuran, cyclohexanone with various medical-grade acrylic polymers dissolved in the solvent for added strength, and various other combinations.

Solvent grades are typically not listed as medical grade or FDA approved but rather by the purity level of the solvent. Obtaining the solvent of choice with the highest purity (99.9% or higher) would limit the potential of leaching chemicals into the water. Sigma Aldrich or Alpha Aesar both provide small quantities of these solvents in various grades for evaluation purposes. Methyl ethyl ketone is an alternative solvent system. However, because of their odor, flammability, and explosive-material storage requirements, using solvents requires special handling and is carefully monitored by the EPA. Dispensing systems such as those offered by Tecnoideal are options to limit operator exposure.

If you want to consider a solvent-free adhesive, looking at a one-part light-curable adhesive such as Dymax’s 1161-M is possible if you can get visible light to the bond line (the nonopaque parts). Alternatively, a two-part urethane or epoxy from companies such as Epoxy Technology or 3M (to name two options) can be considered. These alternatives can provide a bond almost as strong as that provided by a solvent and with fill gaps in the molded ABS bond lines. In addition, they are much more environmentally friendly.