My husband happens to be a Haz-mat specialist, with a highlight on mitigation of weaponable substances.
He says, if it is known to be weaponized Anthrax, the team would be required to use level A protection. That means, they wear protective gear that covers every mm of body surface, with no environmental interface. They would wear an air bottle inside the level A suit, which is totally encapsulating. It has one zipper in the back that has a cover flap The suits are one time use…
The suit has two outflow valves to prevent rupture, since the person exhales into the suit. There is no in flow. It is bottled air, rather than oxygen, oxygen is toxic.
The dressing up takes about 20 minutes, but the air is added last. The air bottle has one hour’s worth of air, so they have about 30 minutes of work time, since the suit can’t be opened until their decon is complete. Otherwise the whole procedure is wasted. Also, they need a buffer since people breathe at different rates and volumes.
The suits cost about $1900.00, one time use. Unused suits must be tested for integrity at least once a year. The do deteriorate, so if at testing a seam fails. out it goes.
The level A suits are blue, the white or yellow suits you might see in movies or on the news, are level B suits, and are not fully contained.
The haz-mat team costs about a million dollars a year per member.
A weaponized Anthrax mitagation could take 20 or more trained people, a year, at a cost of millions.
Now your scenero of an unidentified powder. The level A protection would be used until it was proved to be something other than Weaponized Antharx. That would take a 20 man team, in Level A gear maybe 6- 10 hours to sample and field test the substance. Then a back-up test in a certified lab, before stand down. This at a cost of $70,000 to over $100,000, just to find out it isn’t Anthrax.