Glutaraldehyde is not a particularly dangerous reagent to use, and simple precautions make it quite safe. These are basically the same precautions that would be used with any other laboratory reagent, but with extra attention paid to ensuring that breathing in the fumes and exposing mucous membranes to the fumes are avoided. That can be done by dispensing and using solutions containing glutaraldehyde under a fume hood. To avoid skin contamination, gloves should be worn when diluting the concentrate for use and when removing the tissue from the container.
Spills are likely to be minor, particularly if small bottles of the concentrate are purchased. This is advisable to ensure the reagent is fresh, since glutaraldehyde fixation for light microscopy is not often done in most laboratories. Small spills may be cleaned up with paper towels and lots of water. Ensure adequate ventilation while doing so.
In the event that there is a large spill with inadequate ventilation and any distress due to the fumes, err on the side of caution and safety and get someone experienced in the use of a mask and air tanks to clean up the spill.