By 1986, Ken Alibek explains (in Biohazard), they had over 900 people at the bioweapons plant, and more were coming every month:
There were one or two accidents every week.
Once Gennady Lepyoshkin, the chief of our biosafety directorate, reported that a technician had been infected with anthrax in a lab that was supposed to be sterile. He had an abrasion on his neck, one of the most dangerous places in the body through which to contract cutaneous anthrax. When the neck swells, it interferes with breathing.
At first we treated him with streptomycin and penicillin, the most effective antibiotics for use against cutaneous anthrax, but a painful swelling erupted on his chest and spread over his body, making it increasingly difficult for him to breathe. Within three days, death seemed inevitable. A gloomy message was being prepared for Moscow when, in a final attempt to save his life, we gave him an abnormally high dose of anthrax antiserum. The shock dose worked: he began to recover.
The technician’s narrow escape drove home the potency of our new weapon. Our powdered and liquid formulations of anthrax were three times as strong as the weapons that had been manufactured at Sverdlovsk. It would take only five kilograms of the Anthrax 836 developed at the Kazakhstan base to infect half the people living in a square kilometer of territory; the Sverdlovsk weapon needed at least fifteen kilograms to achieve the same impact.
[…]
Our factory could turn out two tons of anthrax a day in a process as reliable and efficient as producing tanks, trucks, cars, or Coca-Cola.