Ethylene Oxide is not a banned chemical. it is a gas
it is used to sterilize medical devices, usually diluted with
water
Physiological effects:
Effect on
microorganisms
Ethylene oxide inhibits growth of microorganisms (disinfectant properties) and
when present in high concentrations, can completely destroy them.
Strong alkylating properties make ethylene oxide a universal poison
for protoplasm: it causes clotting
of proteins, deactivation of enzymes and other biologically
important components of a living organism.[96]
Ethylene oxide acts more strongly against bacteria, especially
gram-positive bacteria, than
against yeast and fungi.[96]
The disinfectant effect of ethylene oxide is similar to that of
sterilization by heat, but because of limited penetration, it
affects only the surface. The Sterility Assurance Level, after a
certain specified exposure to ethylene oxide is 10−6, meaning that the chance of
finding a single bacterium is below 1 per million.[97]
Ethylene oxide is an alkylating agent; it has
irritating, sensitizing and narcotic effects.[98]
Chronic exposure to ethylene oxide is also mutagenic. The
International Agency for Research on
Cancer classifies ethylene oxide into group 1,
meaning it is a proven carcinogen.[99][100]
A 2003 study of 7,576 women exposed while at work in commercial
sterilization facilities in the U.S. suggests ethylene oxide is
associated with breast
cancer incidence.[101]
A 2004 follow up study analyzing 18,235 men and women workers
exposed to ethylene oxide from 1987 to 1998 concluded "There was
little evidence of any excess cancer mortality for the cohort as a
whole, with the exception of bone
cancer based on small numbers. Positive
exposure-response trends for lymphoid tumors were found for males
only. Reasons for the sex specificity of this effect are not known.
There was also some evidence of a positive exposure-response for
breast cancer mortality."[102]
Ethylene oxide is toxic by inhalation with an U.S.
OSHA permissible exposure limit
of 1 ppm calculated as a time weighted average (TWA) over 8 hours
of 1 ppm, and a short term exposure limit (excursion limit)
calculated as a TWA over 15 minutes of 5 ppm. [29 CFR 19101.1048].
At concentrations in the air about 200 parts per million, ethylene
oxide irritates mucous
membranes of the nose and throat; higher contents
cause damage to the trachea and bronchi, progressing into the
partial collapse of the lungs. High concentrations can cause
pulmonary edema and damage the
cardiovascular system; the damaging effect of ethylene oxide may
occur only after 72 hours after exposure.[15]
The maximum content of ethylene oxide in the air according to the
U.S. standards (ACGIH)
is 1.8 mg/m3.[103]
NIOSH has determined that the
Immediately Dangerous to Life and Health level (IDLH) is 800
ppm.[104]
Because the odor threshold for ethylene oxide varies between 250
and 700 ppm, the gas will already be at toxic concentrations when
it can be smelled. Even then, the odor of ethylene oxide is sweet,
aromatic, and can easily be mistaken for the pleasant aroma of
diethyl
ether, a common laboratory solvent of very low
toxicity. In view of these insidious warning properties, continuous
electrochemical monitors are standard practice, and it is forbidden
to use ethylene oxide to fumigate building interiors in the EU and some other
jurisdictions.[105]
Ethylene oxide causes acute poisoning, accompanied by the
following symptoms: slight heartbeat, muscle twitching, flushing,
headache, diminished hearing, acidosis, vomiting, dizziness,
transient loss of consciousness and a sweet taste in the mouth.
Acute intoxication is accompanied by a strong throbbing headache,
dizziness, difficulty in speech and walking, sleep disturbance,
pain in the legs, weakness, stiffness, sweating, increased muscular
irritability, transient spasm of retinal vessels, enlargement of
the liver and suppression of its antitoxic functions.[98]
Ethylene easily penetrates through the clothing and footwear,
causing skin irritation and dermatitis with the formation of
blisters, fever and leukocytosis.[98]
The median
lethal doses (LD50, or a dose required to kill
half the members of a tested population after a certain time) for
ethylene oxide are 72 mg/kg (rat, oral) and 187 mg/kg
(rat, subcutaneous
injection).[106]
