I definitely want to him to get a replacement, ASAP. Do you mind sharing the health risks? I had found any associated with 0 nicotine. Please share with me what you know. I'd really appreciate it. I'm so sorry for your loss. I will keep you in my prayers.
Since you have asthma, you may find that using a high level (more than 50%) of VG may cause you some breathing problems; I have asthma also, and cannot vape anything more than about 15%-20% VG, or I can't breathe at all.
I won't tell you not to vape; you're an adult, you can make your own choices, but be aware that vaping can be problematic for asthmatics, or others with various lung problems. As a smoker, I didn't require any "maintenance" type meds, just a rescue inhaler, once I quit drinking 22 yrs ago. But recently I've had to return to maintenance meds for my asthma, just so I can keep breathing and stay in control of my asthma. I figure it's worth it because of the long-term risks avoided by quitting a 39 yr smoking habit, and because of all the other gains associated with vaping instead of smoking. In your case, if your stress levels require something to help with that which won't addict you to some horrible pharmaceutical drug, then 0 nic vaping can certainly fill the bill, but for anyone with lung problems, needs to be monitored carefully.
Andria