Other factors include obesity, smoking, stress, pregnancy, and eating too close to bedtime
Applied and Environmental Microbiology 74 , 24612470 (2008)
Since they are reusable, you can use the same folder many times without replacing it frequently
But as you already know that it is equally spread out across 600 puffs so it is not that dangerous
#4 i use a POWERMATIC electric cigg injector, ive had it for about 5 months with no issues, i'd stronglly suggest you look into getting one of these,,,,vs/....them manual machines, i'll allways have my electric machine, and if it goes down i'll get another one, well worth the money,,, you cant go wrong with the name brand POWERMATIC, #5 I've used the PowerMatic for a few years its bullet proof