Interesting. While skimming over the Wiki for micromorts it's reported [1] that Ecstasy has a rating of 0.5 micromorts per tablet. Which I kind of already suspected, given how widely it's consumed versus the rarely occurring yet widely reported deaths that result from its use.
For perspective you get 1 micromort from traveling 17 miles (27 km) by foot. I've walked 8.91 miles (14.34 km) today, which comparatively would be as dangerous as taking an ecstasy pill...well probably not as it would scale differently. I wouldn't be surprised if simply attending a dance-party/rave would have a micromort rating of ~0.5, regardless of substances ingested.