Yes bearded Fireworms are dangerous and poisonous if you touch or handle the bearded Fireworm.
You should never touch a Bearded Fireworm unless you're wearing some good gloves to prevent your skin from getting bitten by the bearded fireworm.
The bearded Fireworms bristles are hollow, venom-filled chaeta which easily penetrate flesh and then break off if this worm is handled.
They are highly poisonous and the venom can kill you if you get it inside your body so you need to be very careful around them and if you do get bitten by a bearded fireworm then you need to seek medical attention right away.
Go to the emergency room right away if a bearded fireworm bites you because they can be deadly.