The burrowing asps are a poorly known group of snakes and their venom profiles, perhaps, even less so. Previous work indicates that asp venom contains mostly sarafotoxins, hemorrhagic metalloprotease, and three-finger toxins (among others). Recent work has shown that pro-coagulation was mediated by factor X activation. Bites in Africa are common but deaths are uncommon, however, there are some documented fatalities, including a recent one by the species Atractaspis corpulenta. Check out the attached articles for more information. Good luck!