Ocular Trauma from Ballast Fluid after a Tractor Tire Explosion

Abstract

Agricultural injury is common and preventable. This study was carried out to investigate a preventable eye injury case in which a tire service employee was blinded while observing the charging of ballast fluid into a tractor tire on a farm. Ballast fluid is commonly added to tires to enhance tractor stability and traction. It is usually a calcium chloride (CaCl2) solution of sufficient concentration to prevent freezing in winter. In this case, in the course of pumping used ballast fluid into a 20-year-old tire, the tire tread was breached and sprayed ballast fluid into the patient's face. The force of the blast was sufficient to knock the patient backward and to break his eye glasses. The patient was transported directly to a local hospital where he received his initial first aid, 20 minuntes after the fluid exposure. By that time there was severe ocular trauma. The patient's left eye developed anterior segment necrosis that included the cornea, conjunctiva, and superficial sclera. The right eye showed conjunctival necrosis, corneal edema, scleral ischemia, and anterior segment inflammation. Analysis of the ballast fluid demonstrated apparent osmolality of 6960 mOsm/L, considerably higher than the physiologic value of 280 mOsm/L. 1,2-Benzisothiazolin-3-one (BIT) and related compounds were identified and BIT was shown to be present at 680 ng/mL. The concentrations of organics in the fluid were likely too low to have contributed significantly to the injury. In vivo toxicology studies performed in anesthetized rabbits demonstrated that the ballast fluid administered without force could not reproduce the severity of injury observed in the patient. Based upon investigation of the incident, medical records, chemical analyses, and toxicology studies, it appears that a combination of physical trauma and hyperosmotic tissue damage was the mechanism of injury. Early treatment by aggressive irrigation with water or saline in the field may have reduced the severity of the injury and prevented the patient's blindness. However, changes in human factors (e.g., use of face shields, no spectators), equipment (e.g., automatic pressure relief valves on pumps), and environment (e.g., perform work in tire shops, place eyewash bottles on service vehicles) could have prevented or minimized this injury.

Full article can be found in: Journal of Agricultural Safety and Health
Access this publication at: ASABE Technical Library