Keeping your Vape Free of Formaldehyde
It isn't difficult to keep safe, and the good news is that it's generally intolerable to inhale when formaldehyde is being generated at significant levels, so you'll know if there is a problem.
If you use conventional e-cigs, like the ones we sell which look a lot like actual cigarettes, the latest study has given very similar products a clean bill of health. See the study here
So you don't need to worry (although it remains advisable to keep the unit refilled or swap the cartridge after it goes dry, but again you'll know by the acrid taste.)
If you are using the higher power, variable voltage systems which have tanks, then follow these steps to stay safe:
1 - Limit power. You are advised to keep the wattage to 5 Watts or less. This generally corresponds to a voltage of 3.3 Volts. Don't go up to 5 volts. The exact voltage depends actually on the Ohm rating of the coil, which usually can be purchased as 1.8, 2.1, 2.5, 2.8 etc. Here you might think that the higher the rating, the more power is used. Actually, it's the opposite, see this link if you wish to calculate power using Ohms Law.
The higher the Ohms number, the less power and heating. So go for a 2.5 or higher Ohm coil. This means that higher voltages can be operated before there is any formaldehyde. The wattage is the best guide to this, and formaldehyde is detected at over 10W. The exact level that is safe isn't known because the researchers only tested certain combinations, but under 5W is certainly in the safe zone.
2 - Go for a bottom filling tank - these have the coil placed at the bottom rather than the top, and you can see this from where the wicks go. This helps prevent the coil running dry, which causes higher temperatures which is the issue. Lowering the wattage by having it on a lower voltage or by higher Ohm coils, should reduce the chances of dry-wick as the e-liquid escapes more slowly.
3 - Try taking shorter lengths of puff, again to prevent dry wick from occurring momentarily.
4 - Keep the tank topped up with juice.