Ethylene Oxide - Q&A
NSW Health Media Release
Friday July 27, 2007
What is ethylene oxide?
Ethylene Oxide is a flammable gas that dissolves readily in water. It is a man-made chemical
used primarily to make Ethylene Glycol (a chemical used to make anti freeze and polyester).
It is also used to sterilise medical equipment and supplies.
How might I be exposed to ethylene oxide?
Exposure to Ethylene Oxide can occur through inhalation or skin-contact.
What limits of human exposure to ethylene oxide have been set in Australia?
Australian health authorities have set a maximum air concentration of Ethylene Oxide
(averaged over a 40-hour week) for a workplace of 1800 micrograms per cubic metre of air
(1 gram = 1,000,000 micrograms).
What is known about typical background air levels?
There is very limited information in Australian and internationally about typical background air
levels. What is known is that there is usually a very small amount of Ethylene Oxide in urban air
and higher levels are found in the immediate vicinity of industries such as sterilisation facilities.
What is the situation at Mona Vale?
Unomedical Pty Ltd is a company that makes and distributes medical products. As part of the
manufacturing process the company uses Ethylene Oxide to sterilize some of its products. This gas
has been discharged into the atmosphere during the final stages of the sterilisation process.
What levels have been identified at Mona Vale?
Preliminary tests indicate that the closest residents to Unomedical may have been exposed to annual
levels in the order of one to two micrograms per cubic metre of air. Although not directly comparable,
this level is about one thousand times lower than the workplace acceptable level.
What do we know about health risks associated with the Unomedical steriliser’s emissions?
Based upon the information we have, it is unlikely that any residents have been exposed to levels of
Ethylene Oxide from the Unomedical facility that would cause immediate health effects. NSW Health is
waiting further expert advice concerning the risk of delayed health effects, if any.
How can ethylene oxide affect my health?
Breathing in relatively high levels of Ethylene Oxide can cause irritation of the eyes, skin and
respiratory passages and affect the nervous system (for example headaches, nausea, vomiting, memory
loss, numbness) in humans. Long-term exposure to Ethylene Oxide at high levels encountered at some
workplaces has also been associated with a small to moderate increase in the incidence of some
cancers. In addition, animal studies suggest that long-term exposure can cause cancer. There is
also some evidence that the risk of miscarriage is increased amongst workers in occupations with
high Ethylene Oxide exposure.
How likely is ethylene oxide to cause cancer?
Cases of leukaemia and other cancers have been reported for workers exposed to high levels of
Ethylene Oxide. While there is no conclusive proof that the chemical causes cancer, the World Health
Organisation has classified Ethylene Oxide as a cancer-causing agent (carcinogen) and the US
Environmental Protection Authority considers Ethylene Oxide a probable cancer causing substance.
On balance NSW Health considers that Ethylene Oxide should be considered a carcinogen.
Is ethylene oxide regulated?
Under the environmental laws of NSW, the release of Ethylene Oxide by the Unomedical factory at
Mona Vale is regulated by Pittwater Council.
What has been done to reduce emission from the Unomedical facility?
As a precaution, Unomedical has been ordered to cease the emission of the chemical ethylene
oxide until acceptable levels, supported by the appropriate testing and monitoring, can be achieved.
What is happening now?
NSW Health has convened a panel of experts to provide further advice concerning the health
implications of emissions from the Unomedical facility. In the meantime, the facility has been
closed and will remain closed until it can be operated safely. The Department of Environment and
Climate Change will be reviewing approval processes, state regulations and guidance materials for
councils, and any other regulatory issues.
How long has Unomedical’s sterilizer been operating?
Unomedical operated in smaller premises in similar vicinity in the 1990’s. They have been operating
in the present facility since 2002.
Is there a medical test to show whether you have been exposed to ethylene oxide?
There are two kinds of tests that can determine if a person has been exposed to Ethylene Oxide.
One test measures Ethylene Oxide in blood and the other test measures it in your breath. However
these tests cannot be used to predict how it will affect your health and are largely used to monitor
workplace exposure levels.
What should I do if I feel I may have been exposed to Ethylene Oxide emissions from the Unomedical
facility?
The current advice is that it is unlikely that residents will have any immediate health effects
from the emissions.
NSW Health is awaiting further investigations and advice from a panel of experts to assess the
health implications (if any) from past emissions. At this stage there is no need to seek additional
medical care as a result of Unomedical’s ethylene oxide emissions. Should your require additional
information, a list of contact numbers is provided below. Alternatively you may wish to speak to
your General Practitioner. NSW Health has advised local General Practitioners about the current
situation.
How can I find out more about the current situation?
NSW Health, the Department of Environment and Climate Change and Pittwater Council will keep
local residents updated with new information as it becomes available. Should you require specific
advice on any of the following issues please contact the appropriate agency as listed below;
Health issues
Northern Sydney Central Coast Public Health Unit
Phone: 02) 9477 9188
Regulation of emissions
Pittwater Council – Phone: 9970 1111
Regulatory support
Department of Environment and Climate Change
Phone: 131 555
