It sounds like the nicotine might be low quality or oxidized.

Troubleshooting

Where did it come from?

How long did it take to ship to your house and in what conditions (hot/cold climate)?

How do you store the nicotine? Location, temperature. Sealed?

Do you shake the nicotine very well before putting it into your mixes?

Does the nicotine have a certain look or smell to it?

My asthma is mildly triggered by oxidised nic and a few heavy flavors. It's tough to pin down an issue based on the anecdotes of others, however, since triggers are varied from person to person and may also be a combination of factors like environment and even little things like the time of day (my symptoms appear mainly at night, and this is fairly common.) Still, I'd check the quality on your nic and if it's an option, try a different supplier.

I would assume that most nicotine you get will be decanted into 10mL bottles from larger bottles, without using another gas to keep oxygen at bay.

Have you tried the nicotine salts? I'm not sure what exactly is causing your particular issue, but nic salt seems to be a lot less irritating/harsh.

This is interesting to me as a chronic asthmatic myself. The only thing I've found that has triggered my asthma since vaping has been anything with vanilla bean ice cream flavouring in it. I'm fine with anything else

For me higher nic has triggered asthma as well as some cinnamon flavorings. I made it down to 1.5 and have been pretty good recently. Also the cinnamon only triggers me when I try to shake and vape it. After a long steep it's fine.

That's exactly what it is. Your nicotine is low quality or oxidized

Adding 7.5ml of PG Nic to 60ml of 70VG/30PG base will give you 67.5ml of 62VG/38PG. That's pretty high especially at 6mg Nic. This could definitely be your problem.

Not all nicotine is made/filtered equally. So far I prefer Nude Nicotine brand.

any possibility there could be a massive difference in nic PG bse or nic VG base?

Thinking am going to get some more nic i might aswell try it in VG base?

There are definitely variations in nicotine bases, particularly thier quality. Usually when it starts tasting peppery it's degrading but not always, some brands are indeed simply smoother than others. If it's this harsh now I doubt it's going to subside to a level you can vape it. If funds allow I would recommend ordering from Hiliq, their nicotine base is quite smooth, worth trying. If you want my honest opinion it's the nicotine you're using (it shouldn't be that harsh). I've been mixing myself and understand the headaches a poor base can cause the testing, troubleshooting etc. Unless someone else has a suggestion I'd jump onto Hiliq and count your losses , like you said, the premade juices you buy aren't doing it.

Can you tell us where you got your nicotine from? I just got 100ml from nicotineUK (first order with them) and it seems fine (@ 72mg/ml).

thanks for the replies guys, i had bought the PG nic a while ago and had the same effect brand new so no oxidising yet - i think the best theory is the brands that can differ.

My biggest problem is that i cannot import any nicotine into the UK anymore since the TPD bollocks thats come in.

So am stuck buying 20mg/ml in 10ml bottles for £5 (bout $6 usd) so for 60ml of juice to be 6mg it needs around 18ml which nearly £10 just for nicotine! looks like store bought it the best way to go

I had the same issue with some of my DIY (both flavor and nic) and find it's really hard for me to track down which ingredients set me off. I've kind of moved back towards some of my tried and true premiums that irritate me less...but in general vaping really hammers my lungs compared to analogs and I've tried every combination of everything DIY and different vendors, pg/vg, and flavors. It's always a crapshoot when I mix something with a new nic source or flavor I haven't used.

I recently picked up one of those Cync cigalikes. Not sure if you can get them there, but I've been using it almost exclusively the past few weeks and BOY my lungs are SOOOO much happier. I've actually developed a huge liking for it (went back to my crown 3 to vape my favorite flavor and found myself craving the cigalike). My sinuses have been better with the cigalike as well. I think a lot of it for me is just the density of the vapor that's irritating my lungs and I think some of it gets into my ears and gives me tinnitus and ear pressure as well. Even when I run my big rigs with the coils cooler than the recommended wattage still just seems to cause me a lot more irritation.

Just wanted to say that cigalikes seem to have improved a lot as of late, and maybe give one a try if you haven't in a while. For the cync my favorite flavors they offer so far is the tobacco,nut,coffee one, the neon sherbet, and the strawberry rhubarb (in case you check it out and can get them there). I tried a dozen other flavors and didn't like any of the others so far.

Store bought juice doesnt have as much nicotine as advertised. Lower your nic percentage and give it a go.

Look into purchasing nicotine salts. They are much less harsh then nicotine extract that is traditionally used. That is what they use in the JUUL, that is 50mg/ml.

Also, there has to be an easier way to buy unflavored, 99.97% vg. It has a lot of other uses besides vaping.

Somebody with first had experience with this. Please give this a shot before you quit DIY.

1. Use only 100mg/nic so you can use less of it to achieve the same strength.

2. Let juice immediately sit in hottest possible tap water for 3 minutes, shake well about halfway through the 3 minutes.

3. Let sit with the lid off for MIN 8 hours.

My asthma will always trigger if I attempt to made a "fresh" made bottle, It seems to have something to do with the "fumes" almost alcoholically smell you get from "fresh" flavours. Even just smelling the juice feels like its plugging me up. After 8-10 hours with the cap off this really seems to go away.

Let me know if it helps

Without a doubt it sets off asthma. At least for me anyway. But I can say this I use my Ned's way less than when I smoked.