Many hospitals have already moved away from using EtO sterilization to other methods. Since EtO was recognized as a known human carcinogen in 1994, the estimated total tonnage of EtO used by U.S. hospitals has dropped from about 1000 tons per year to approximately 135 tons per year in 2005.

A number of other sterilization technologies exist. Many of these can replace some but not all EtO applications, so a hospital's sterilization strategy may include two or more options. These include steam, chemical sterilization with less-toxic processes such as sonic sterilization, gas plasma, electron beam, microwave, or hydrogen peroxide.

One hospital, for example, estimates that they have been able to reduce EtO use by 60-70%, but that EtO is still used, with proper safety precautions for angioscopes, choledocoscopes, surgiiscopes, bone flaps, and hysterectoscopes.

If EtO is still used for some purposes, the following practices will reduce hazardous emissions and risk to employees and patients.

• Sterilize full loads to the extent practical.
• Use self-contained scrubbers, combustion units, or gas collection to prevent EtO from escaping into the air.
• Recover and dispose of EtO as dangerous waste.
• Filter air and dispose of spent filters as dangerous waste.
• EtO may be manufactured with another gas as a carrier. Choose EtO with less-toxic carriers such as carbon dioxide or 100% ethylene oxide. Prior to the ban on chlorofluorocarbons, Freon was a carrier gas, which added to the toxic emissions. Note that the carrier gas doesn't add to the sterilization efficacy so the concentration of EtO has to be sufficient for proper sterilization.

Alternative Sterilization Options: Advantages and Disadvantages

Some available alternative sterilization options include the following list. Potential pros and cons are listed in the tables below.

• Plasma phase hydrogen peroxide
• Peracetic acid
• Ozone
• Ionizing radiation
• Steam or dry heat autoclaves
• Disposable single use devices (SUD)
• Reprocessed/sterilized SUDs
• Chlorine Dioxide (ClO2)
• Pulsed light systems

1. Plasma phase hydrogen peroxide

Advantages	Disadvantages
Acceptable alternative in many cases	Some manufacturers haven't approved this method for their devices yet (such as mixed material devices)
Shorter processing time = higher productivity	High initial cost
No utility connection except power	Items must be completely dry
No waste	No paper or liquids
Completely sealed sterilant eliminates contact
Automated processing
Small footprint
Moderate cost per cycle
Single channel flexible endoscopes can be processed

2. Peracetic acid

Advantages	Disadvantages
Acceptable alternative in many cases	Some manufacturers haven't approved this method for their devices yet (such as mixed material devices)
Shorter processing time = higher productivity	"Just-in-time" technology; so sterilized items must be removed from the unit and used immediately, which makes it impractical in certain applications
Small footprint	Limitation on types of scopes that can be processed
Closed automated system	Is an irritant and possible problem for asthmatics
	Highly toxic and corrosive substances
	High repair costs

3. Ozone

Advantages	Disadvantages
Devices don't have to be completely dry to process	New untested technology
Large capacity	Can't reprocess flexible endoscopes
Closed automated system	Many materials are incompatible
No toxic waste	Possibility of O2 enriched atmosphere
Water and electricity are the only utilities needed
Low cost per cycle
Conditionally approved by the FDA

4. Ionizing radiation

Advantages	Disadvantages
May be used for product designs and packaging materials that are impermeable to gases as long as they are "transparent" to energy of the wavelengths employed in the sterilization process

5. Steam or dry heat autoclaves

Advantages	Disadvantages
Good alternative for many traditional surgical instruments	High pressure and high temperature makes this alternative unsuitable for products that are sensitive to heat, like mixed media instruments, rubber, plastics, glass and those affected by the corrosive and dielectric effects of steam
Comparable to chemiclaves without the hazardous waste	Disposal of wastewater may be subject to state regulation

6. Disposable single use devices (SUD's)

Advantages	Disadvantages
Eliminates need to sterilize devices	Creates direct increase in solid and hazardous waste
Eliminates internal costs and workload	Higher Cost

7. Reprocessed/sterilized SUD's

Advantages	Disadvantages
Outside provider takes the responsibility of sterilization. Eliminates internal costs and workload	Dependant on reliability of vendor
Reduces solid and hazardous waste	May not reduce EtO if reprocessor is using it

8. Chlorine Dioxide (ClO2)

Advantages	Disadvantages
No significant levels of residual sterilant on product	Can't be safely stored under pressure for transport and subsequent use since it is explosive in liquid form
Not flammable in gaseous systems	Unstable and corrosive in liquid form
Used for contact lenses and foil suture packages	Concentration rapidly diminishes when in liquid form
When used with stabilizing agents, liquid form is used for fiber-optic endoscopes

9. Pulsed light systems

Advantages	Disadvantages
Reported to be effective killing micro-organisms including spores	Effectiveness depends on light access to surface, so porous surfaces, turbid liquids and non-transparent materials are not applicable
Low costs around one cent per square meter sterilized	Possible degradation of surface of opaque materials

Specific sterilization options vary by vendor and by type of device. Some of the characteristics to consider are the following:

• Processing time
• Up front cost
• Ongoing costs for supplies
• Length of time devices remain sterile
• Residue requiring special handling or not
• How wastes can be neutralized
• Types of devices accommodated; soft metals, plastics, packaging

For a detailed list with pros and cons by vendor name brands, see the Vendors List: Less Hazardous Products and Waste Management in the link to the Best Management Practices for Hospital Waste from the Washington Department of Ecology, http://www.p2rx.org/topichubs/externallink.cfm?l=6504.

Keep the following tips in mind when choosing a vendor: [1]

• Ask for least toxic products available. Ask if they have products that do not become dangerous waste when spent or are recyclable.
• Ask vendors for customer references (name, phone and address) that use the product or service in the same manner you will be using it. Contact these customers and ask for their opinion of the product or service. Ask the customers what they like or don't like about the product or service.
• Contact your state ecology office for vendor's compliance history.
• Get a number of bids and compare. Choose your vendors carefully; consider reliability as well as costs.
• Test the product or service to see if it satisfies your requirements prior to making a commitment to purchase the product or use the service.
• Ask if the product or service is "drop in" prior to product purchase or service use or if new equipment will be necessary. Ask to see total costs or fees associated with the product or service.
• Whenever possible, require your waste contractor to pick-up only on request. In your contract with your waste hauler, have it clearly written that they will only pick up on request. Keep wastes separate, if necessary. Don't over-accumulate wastes. Fill all containers prior to disposal. Keep containers closed, labeled and in good condition and stored in secondary containment, when necessary.
• Know the fate of your waste. You are ultimately responsible for the proper disposal of your waste.

Source:
[1] Best Management Practices for Hospital Waste, Washington Department of Ecology http://www.ecy.wa.gov/pubs/0504013.pdf