Under stable circumstances, when the bottles are kept upright, or at least in a cool, dark location, the pure DMSO, 20% or 40% eyedrops, DMSO with colloidal silver, or DMSO with added nutrients doesn’t come into contact with the synthetic rubber dropper, but when traveling changes in position, pressure, and/or temperature may force the DMSO up through the hole in the glass dropper which can degrade the stopper material slightly. To help reduce this issue, when putting the glass dropper back in the bottle, first make sure it is fully evacuated. Although a rare occurrence, we suggest if you are traveling with your products, use this alternate phenolic plastic cap. This of course can also be used for long-term storage of products.
PLEASE NOTE: These caps may not work with existing 30mL and 50mL dropper bottles, as the threading is different. They must be ordered along with the product (we have to use specific bottles to fit with these caps)