Acute inhalation toxicity of aerosolized electrochemically generated solution of sodium hypochlorite

Objective: The objective was to determine the inhalation toxicity of the electrochemically generated sodium hypochlorite solution after its single administration to laboratory animals in the form of a highly dispersed aerosol. Materials and methods: The study has been conducted according to the OECD Test Guideline No403 'Acute Inhalation Toxicity.' Laboratory animals were exposed to inhalation of an aerosol containing 1.7 +/- 0.13 mg/m(3) of active chlorine. The hematological and biochemical parameters of the blood of experimental animals have been determined, as well as specific parameters: the activity of cathepsins B and L, catalase, and alpha 1-antitrypsin. Histological study of the lungs of animals has been carried out. Results: During inhalation and 14 days after it, no death of the animals was observed; the behavior, appearance, and weight gain did not differ from the control group. There were no significant deviations in hematological parameters, except the decrease in the level of platelets. The biochemical study showed slight changes in the activity of alkaline phosphatase and aspartate aminotransferase on the 1st day after inhalation; these parameters returned to normal within 14 days of observation. Specific biochemical parameters did not show the development of oxidative stress. No specific histological pathologies of lung tissue have been found. Conclusions: Thus, the studied electrochemically generated sodium hypochlorite solution under single inhalation exposure in aerosol form practically does not cause a toxic effect. The data obtained allow classifying such solution to the 4th (or even 5th - after additional studies) class of toxicity in accordance with Globally Harmonized System of Classification and Labeling of Chemicals.