[The acute toxicity of a bacterial insecticidal preparation containing a beta-exotoxin]

The acute toxicity of a new Bulgarian bioinsecticide preparation is determined, produced on the basis of Bacillus thuringiensis containing 0.1% beta-exotoxin by oral, dermal, inhalational and intraperitoneal introduction in experimental animals. The evaluation of the toxicity is performed by a complex of toxicometric, integral, haematologic and pathologicoanatomic methods according to the WHO and USA criteria for studying the safety of the microbic agents for plant protection. It is already established that the preparation introduced orally in dose 10,000 mg.kg-1 (1.6.10(11) cell kg.-1 10 micrograms.kg-1 beta exotoxin), applied dermally in dose 6000 mg.kg-1 (9.6.10(10), 6 micrograms.kg-1 beta exotoxin) and in concentration 300 mg.m-3 (4.8.10(10) cell m-3, 300 micrograms.m-3 beta exotoxin) provokes no lethality, intoxication and changes in the integral, haematologic and pathologicoanatomic studies of test animals. LD50 at intraperitoneal introduction in white rats is 387.20 mg (6.2.10(10), kg-1, 387.2 micrograms kg-1 beta exotoxin) for male and 364.0 mg kg-1 (0.58.10(9) kg-1 364.0 micrograms kg-1 beta exotoxin) for female animals. The investigations point out that according to rate of acute toxicity the bacterial preparation containing 0.1% beta exotoxin is referred to the low toxic substances and reveals no danger for acute oral, dermal and inhalational poisonings when the regulations for production and use are observed.