J Vet Sci.  2023 Mar;24(2):e22. 10.4142/jvs.22253.

Assessment of acute inhalation toxicity of citric acid and sodium hypochlorite in rats

• Kim J
• Park CM
• Choi SH
• Yang MJ
• Lee JY
• Jeon BS
• Ku HO
• Kim MS

• KMID: 2541335
• DOI: http://doi.org/10.4142/jvs.22253

Abstract

Background
Citric acid (CA) and sodium hypochlorite (NaOCl) have been used to disinfect animals to protect them against avian influenza and foot-and-mouth disease.
Objectives
We performed a good laboratory practice (GLP)-compliant animal toxicity study to assess the acute toxic effects of CA and NaOCl aerosol exposure in Sprague-Dawley rats.
Methods
Groups of five rats per sex were exposed for 4 h to four concentrations of the two chemicals, i.e., 0.00, 0.22, 0.67, and 2.00 mg/L, using a nose-only exposure. After a single exposure to the chemicals, clinical signs, body weight, and mortality was observed during the observation period. On day 15, an autopsy, and then gross findings, and histopathological analysis were performed.
Results
After exposure to CA and NaOCl, body weight loss was observed but recovered. Two males died in the CA 2.00 mg/L group and, two males and one female died in the 2.00 mg/L NaOCl group. In the gross findings and histopathological analysis, discoloration of the lungs was observed in the CA exposed group and inflammatory lesions with discoloration of the lungs were observed in the NaOCl exposed group. These results suggest that the lethal concentration 50 (LC50) of CA is 1.73390 mg/L for males and > 1.70 mg/L for females. For NaOCl, the LC50 was 2.22222 mg/L for males and 2.39456 mg/L for females.
Conclusions
The Globally Harmonized System is category 4 for both CA and NaOCl. In this study, the LC50 results were obtained through a GLP-based acute inhalation toxicity assessment. These results provide useful data to reset safety standards for CA and NaOCl use.

Keyword

Disinfectants; acute toxicity tests; lethal concentration 50; Sprague-Dawley rats