If you use large quantities of hazardous materials, you may want to invest in a local exhaust system. This system involves a hood to collect the contaminants, ducts to carry them outside and an exhaust fan to remove them from the exhausted air. While more expensive to install, it is less expensive to maintain. If you cannot ventilate your studio, or your need for ventilation is only occasional, a respirator should be considered. Respirators come with removable cartridges that must be matched with the contaminants you are trying to filter.
All cartridges eventually lose their effectiveness and have to be replaced.
To be safe, change cartridges every two weeks or after eight hours of cumulative use. If the contaminant can be smelled while wearing a respirator, a cartridge change is long overdue or the respirator does not fit properly. It is unwise to use a respirator with a toxic chemical that cannot be smelled. Consider two factors when purchasing a respirator. Two, make sure it fits properly.