Well, it isn’t strictly necessary for safety reasons.
As long as the vial is sterile and airtight that does the job.
The vacuum seal offers more perceived than actual effect.
I’m sure some would disagree, but the fda agrees - that’s good enough for me (technically they don’t mandate vacuum seals, so to be accurate they don’t disagree with me and that’s good enough for me).
Interesting....
I would imagine that's providing the crimps were done right. I've had a couple that wouldn't hold a vacuum, and that makes me think the crimps aren't sealed.
Coming from gray/black market labs in China is not as comforting as being produced in an inspected lab in the US that has oversight.
My perception is that if it's vacuum sealed, then air can't get in. So I certainly feel better when I tap a vial that has a vacuum.
I'm not a chemist or expert on sterility, but if air can get in, so can bacteria.
Coming from labs that probably aren't inspected, and not seeing anyone produce video of the finishing being done in a clean room... having that added security lets me know that even if it was exposed in transit or packaging, nothing got in.
I guess you could argue that the vacuum, combined with a leak, could suck in more bacteria than if it wasn't vacuum sealed.
The lack of 3ml sterile vials being available and what I recently learned about the lack of sterility in general is one of the reasons I'm seeking to filter into vials that have a sterility certification.
On that note - you might benefit from showing your processes in a video so that your customers can see, if nothing else, it's not just 3 guys sitting around a kitchen table, smoking cigarettes, doing shots of tequila, and spooning powder into vials, slapping crimps on them and tossing them into a box.
It's best not to leave these things to people's imagination.