Ethylene Oxide: Acute Four-Hour and One-Hour Inhalation Toxicity Testing in Rats

Table 1

Clinical observations, mortality rates, and day of death for male rats following 4-hour exposure to EO.

Exposure group (ppm)	Clinical signs		Mortality	Number found dead; Observation day
	During exposure or same day following exposure	During five days of postexposure period	Number dead/total	0^a	1	2	3
2182	Periocular/perinasal/perioral wetness, gasping, audible respiration, hypoactivity	Periocular/perinasal/perioral encrustation, unkempt fur, decreased respiration rate, hypoactivity	4/5	1^b	2	1	0
2026	Periocular/perinasal/perioral wetness, gasping, audible respiration, hypoactivity, absence tail/toe pinch reflex	Periocular/perinasal/perioral encrustation, unkempt fur, gasping, audible respiration, decreased respiration rate, hypoactivity, tremors,	4/5	0	3	1	0
1850	Periocular/perinasal wetness, gasping, audible respiration, hypoactivity	Perioral/perinasal encrustation, unkempt fur, audible respiration, decreased respiration rate, hypoactivity	0/5	0	0	0	0

^aDay 0 is exposure day. Days 1, 2, and 3 are days following exposure day.
^bNumber of animals found dead on a particular day.