Unfortunately, the safety factor of Delta-8 THC was never touched upon.
A study (by L E Hollister & H K Gillespie, 1973) compared Delta-8-THC with Delta-9-THC in both oral and intravenous administrations. Both substances produced the same effects on the subject when introduced intravenously. However, in oral administration, Delta-8 was discovered to have milder effects than Delta-9.
There are only limited human studies about Delta-8. Its side effects, safety profile, and tolerability remain unknown. The only thing that we know is its milder effects compared to Delta-9-THC. Moreover, other routes, including vaping and smoking, have no studies available to describe their impacts and safety. It’s also impossible to confirm if Delta-8 is entirely safe for human consumption.
With this in mind, it’s best to conclude that more research is required for Delta-8-THC.