The Burning Question of many DIYers....
The question for whether DIY’ers should use glass or plastic keeps popping up in groups, so I thought I would tackle this topic for an easy reference point in the future. There are many factors to take into consideration, so it is a surprisingly more complicated answer than one might think. For that reason I will discuss the pros and cons of each separately. I tend to use a mixture of both glass and plastic for my e-liquid mixing. For example, I like to use glass for the mixes that need to steep because plastic has a tendency to leech the flavor. However for flavor testing and recipe revisions I prefer to use 10 ml plastic bottles because they are cheap and recyclable. I tend to mix 10 or more bottles at a time at least a few times per week. That would be way more glass bottle washing than I want to mess with! There is also the issue of most recipes needing to steep and be tested again at a later date. Which means that even if I wanted to wash that many bottles, I would still need around 100 or more just to have enough on hand for my recipe testing rotations. I will outline the biggest advantages and drawbacks, for each one separately so that you can decide which one is a better fit for you.
The ability to be soft and squishy make these bottles very appealing. They are also inexpensive and recyclable not to mention they do not break as easily as glass. The flavor can permeate the plastic and make them tricky to reuse. The one thing to remember is to be certain that you have a plastic that is formulated to hold vape juice as some plastics are more prone to break down due to acidity.
Using the wrong kind of plastic can can lead to the container corroding and leaking contaminets into your liquids for the same reason they removed things like BPA from your plastic food containers. You want to use plastics like HDPE, LDPE or PET. However the vast majority of products being used for DIY start out in a plastic container so obviously using the correct plastic is fine. For example, things like Nicotine, Propolyene Glycol, Vegetable Glycerin and most food flavorings tend to arrive in HDPE plastic containers. Generally speaking they have been stored in plastic drums (which are often HDPE) until they were ready for distribution. Soda is far more acidic than the average e-juice and is routinely stored in (PET) plastic. The goal is not to scare you, but to point out why it is so important to use the right kind of plastic for DIY, and not random food storage or reused food containers that may not be the correct type of plastic. When in doubt check what the little number is inside of the triangle which appears on the plastic, and check the number to see if it is either LDPE(4), HDPE(2), or PET(1) which are the most commonly used for E-liquid plastics.
If you decide to go with glass it is a good idea to go ahead and opt for the amber or cobalt variety. Sunlight can degrade your flavor molecules and these bottles are designed to give some protection from that. There are even more expensive types that block UV too, think of it as sunblock for your liquid. Glass can also be washed and reused numerous times thereby saving you money.
It is not a permeable material so the flavors will not leech into it. It may be a good idea to buy extra droppers if you are concerned about the flavor leeching into the bulb of the droppers. It is also handy to have spares in case any of them break during use. Some people feel that the glass bottles look more professional. Glass is also recyclable. It does have disadvantages; for example, if you are a tank user you may want to use a little extra precaution while filling your tank up as the tip can get caught and break off rather easily. It also takes a bit more patience to get that last drop of your precious concoction from the bottom of the bottle. It can also break much more easily than the plastic counterparts would when it gets dropped. But being reusable and washable does give you bottles that you will have until they break. They can be boiled or put in the dishwasher to be cleaned. Baby bottle cap holders that go in your dishwasher work wonders for the dippers and caps and bottles so they don’t end up all over your dishwasher.
Ultimately it will be up to you as the DIY’er to decide which one, or a combination of both, that makes the most sense for you and your mixing style. Whichever one you decided upon, I do reccomend buying in bulk whenever possible because it will be the cheapest option in the long run. I hope this will help you go forth and make an informed decision. As always… Happy Mixing!