People have varying sensitivities and it is really hard to say absolutely not - it would be unlikely to be fatal if taken on its own but not impossible, especially if combined with other downers.
LD50 is the dose that would be fatal for 50% of people (it's not very accurate really and is often extrapolated from animal studies) - it also doesn't take into account variation in tolerance.. thank you for the info though, 500-850mgs is interesting! Presume that is for opioid naive people.
Why do you want to know xbloodwhipx?