A printer system using inks, toners or developers with solvents therein is provided with a detector for volatile organic compounds assists in reducing potential accidents in the printer. The detector may be able to identify at least a threshold level of volatile organic in a gas phase in the printer, or may be able to identify various levels or a continuous metered level of volatile organic compounds (VOC's). An automatic warning, automatic signal, or even automatic cutoff function may be associated with the detector. The detector may be inside the printer or associated with a vent or generally positioned on or near the printer. One mode of detection operation described in detail is identification of changes in dielectric constant in a vapor phase or vapor stream that can be associated with changed levels of VOC in that phase or stream.