United States 

Department of 

Agriculture 

Animal and 

Plant Health 

Inspection 

Service 

Policy and Program 

Development 

Environmental and 

Risk Analysis 

Services, Unit 149 

4700 River Road 

Riverdale, MD 

20737 

USDA 

iiiiii 

Ms. TaWanda Maignan, Section 18 Team Leader 

Risk Integration, Minor Use, and Emergency Response Branch 

Office of Pesticide Programs (7505P) 

U.S. Environmental Protection Agency 

1200 Pennsylvania Avenue, N.W. 

Ariel Rios Building 

Washington, DC 20460 

ATTN: Ms. TaWanda Maignan, Section 18 Team Leader 

ENQL 7-1 CY13 

PERMANENT 

Retire 03118 

March 26, 2013 

Risk Integration, Minor Use, and Emergency Response Branch 

SUBJECT: Request to Renew Ethylene Oxide Quarantine Exemption 

(EPA File SymbollO-DA-01) 

Dear Ms. Maignan: 

The United States Department of Agriculture (USDA) Animal and Plant Health Inspection 

Service (APHIS) is requesting to renew their ethylene oxide quarantine exemption (EPA File 

Symbol10-DA-Ol) approved for use on March 11, 2010. This exemption allowed for the 

sterilization of interior surfaces of enclosed animal isolator units used at USDA National 

Veterinary Services Laboratories (NVSL) and the National Animal Disease Center (NADC) 

in Ames, Iowa (EPA File Symbol10-DA-01). 

NVSL and NADC provide diagnosis for animal diseases and diagnostic support for disease 

control and eradication. Without the ability to sterilize animal isolators, NVSL and NADC 

would not be able to conduct studies of national importance. Ethylene oxide is an effective 

sterilizer, yet is non-corrosive on delicate instruments and electrical equipment. 

Oxyfume® 2000 (EPA Registration Number 67470-8) was the only product approved for use 

under the previous exemption. This product will only be available for use up until December 

31, 2014. Prior to this date, APHIS intends to submit an amendment request and replace 

Oxyfume ® 2000 with an alternate product. 

If you have any questions regarding this application, please contact Samantha Bates Floyd at 

(301) 851-3053 or e-mail Samantha.B.Floyd@aphis.usda.gov. 

Sincerely, 

ff~ a.. n~:~:_... -F'trr ,r-· 

David S. Reinhold 

Chief, Environmental and Risk Analysis Services 

Policy and Program Development 

Attachment 

APHIS Safeguarding American Agriculture 

.o::;::;e::;; APHIS is an agency of USDA's Marketing and Regulatory Pr~grams 

... An Equal Opportunity Provider and Employer 
Ms. Maignan Page 2 

cc: 

R. Stoker, USDA, APHIS, Ames, IA 

DS file: Section 18/Ethylene Oxide (10-DA-01) renewal/FY2013 
TYPE OF EXEMPTION BEING REQUESTED

QUARANTINE EXEMPTION

 

CONTACT PERSON AND QUALIFIED EXPERT

Name: Samantha Bates Floyd

Title: Biological Scientist

Organization: U.S. Department of Agriculture, Animal and Plant Health Inspection Service

Address: 4700 River Road, Unit 149 Riverdale, MD 20737

Phone: (301) 851-3053

E-mail: Samantha.B.Floyd@aphis.usda.gov

DESCRIPTION OF PESTICIDE REQUESTED

Product Name: Oxyfume® 2000 (until December 31, 2014)

Active Ingredient: Ethylene Oxide, CAS No. 75-21-8; C2H4O4

EPA Registration Number: 67470-8 

% Active Ingredient(s), Formulation(s): 8.6 % 

Manufacturer: Honeywell, 101 Columbia Road, Morristown, NJ 07962-1053

DESCRIPTION OF PROPOSED USE

Sites and area to be treated: 

Gnotobiotics is the scientific study of animals or other organisms raised in environments that are free of 

germs or that contain only specifically known germs. Scientists compare gnotobiotic animals with 

ordinary animals whose bodies carry many bacteria, viruses, and parasites. In this way, scientists can 

determine more precisely how specific germs affect the body. Scientists also use these germ-free units to 

raise animals for antibody production and the subsequent collection of their sera. 

The United States Department of Agriculture, Animal and Plant Health Inspection Service’s National 

Veterinary Services Laboratories (USDA APHIS NVSL) provides diagnoses for animal diseases and 

diagnostic support for disease control and eradication of programs of national importance. As such, 

NVSL conducts animal research requiring the use of a germ-free environment. The National Animal 

Disease Center (NADC) is co-located with NVSL in Ames, IA. The NADC is the largest federal animal 

disease center in the United States. The NADC conducts research to solve animal health and food safety 

problems faced by livestock producers and the public. There are animal experiments at the NADC that 

require a germ-free environment. 

Under this Section 18, ethylene oxide would be used to sterilize the interior surfaces of self-enclosed 

animal isolator units used in NVSL and NADC in Ames, IA. The animal isolator units are composed of 

plastic material with PVC pipe connections and some stainless steel connections. The photographs 

located at http://www.cbclean.com/isolators/34875-2x.jpeg (see appendix 1) are representations of animal 

isolator units. The isolator units used by APHIS and the Agricultural Research Service (ARS) in Ames 
DESCRIPTION OF PROPOSED USE

are tub isolators suitable for baby pigs or a calf. Pig isolators made of PVC plastic are 26” by 43” by 32” 

in size and fit over a 24” by 42” by 24” stainless steel base. A second (auxiliary isolator) is used to store 

feed and supplies during an animal experiment. Items are transferred from the auxiliary isolator to the 

animal isolator through a sleeve between both isolators. The secondary isolator is 30” by 48” by 30” in 

size. The base of the calf isolator (also made of stainless steel) is 50” by 25” by 16” and the plastic cover 

is 90” by 34” by 32”.

Method of application: 

Six pounds of Oxyfume® 2000 is added to each animal isolator unit using a compressed gas cylinder. 

The scale used to measure the addition of ethylene oxide gas to isolator units has a welded base and 

securing mechanism to ensure the ethylene oxide cylinder does not inadvertently tip over. Oxyfume® 

2000 will be added to each isolator (6 lbs to the animal isolator and an additional 6 lbs to the auxiliary 

isolator) through a hose coupling (i.e., injection port). 

Rate of application (in terms of active ingredient and formulated product):

As described above in the section on the method of application, 6 lbs. of Oxyfume® 2000 is applied to 

each animal isolator unit.

Maximum number of applications:

Animal isolator units will be sterilized 5 to 7 times with Oxyfume® 2000 over the 3-year term of this 

exemption; a maximum of 9 tub isolators for pigs, 9 auxiliary isolators that attach to the tub isolators for 

pigs, 2 tub isolators for calves, and 2 auxiliary isolators that attach to the tub isolators for calves would be 

sterilized under this Section 18 per year. Alternatively, a total of 13 auxiliary isolators may be used to 

isolate mice while operating 2 calf isolators at the same time.

Total amount of pesticide to be used (in terms of active ingredient and formulated product): 

A total of approximately twelve pounds of product to fumigate one tub isolator for pigs hooked up to one 

auxiliary isolator. The same amount is used to fumigate one tub isolator for a calf attached to an auxiliary 

isolator.

Additional restrictions, user precautions, and requirements, qualifications of applicators, etc.: 

To be used only by persons experienced in Oxyfume® 2000 sterilization and fumigation. The product

may be used safely to sterilize animal isolators and the equipment and supplies placed within isolators. 

Oxyfume® 2000 may be used only in facilities that meet the requirements of 29 CFR 1910.1047. The 

product may be used only by persons who have been trained in accordance with 29 CFR 1910.1047.

Duration of the proposed use:

As needed in preparation for experiments in veterinary research. The use of an isolator is dependent on 

the length of the last animal study and logistics (i.e., the time for an animal order and necessary 

experimental supplies to come and time to clean and fumigate the bubble). 
ALTERNATIVE METHODS OF CONTROL

(Efficacy data and/or other information included as a separate attachment)

Registered Alternative Pesticides:

Alternative sterilizers containing ethylene oxide are available, but none contain the specific percentage of 

ethylene oxide and other refrigerant chemicals that Oxyfume® 2000 contains. 

Ethylene oxide is non-corrosive on delicate instruments and electrical equipment. There are no good 

alternative methods of control. The possibility of using Clidox, Vaporized Hydrogen Peroxide (VHP), 

and Paraformaldehyde was considered, but these substances are not viable alternatives. Clidox would 

corrode the stainless steel portion of the isolator, VHP would only provide surface decontamination, and 

paraformaldehyde would leave a residue that would be potentially detrimental to the animals in the

isolator.

Alternative Control Practices: 

Cleaning the animal isolator units with general cleaning products provides some level of reduction of the 

microbial load, but it is not as effective as general cleaning followed by sterilization with ethylene oxide. 

Due to the nature of the experiments being conducted, assurance of a sterile environment is critical.

EFFICACY OF USE PROPOSED UNDER SECTION 18

(Efficacy data and/or other information included as a separate attachment)

Ethylene oxide is a sterilant that destroys or eliminates all forms of microbial life in the inanimate 

environment, including all forms of vegetative bacteria, bacterial spores, fungi, fungal spores, and 

viruses. All registered ethylene oxide products making sterilization claims have passed efficacy tests for 

their registered uses.

EPA-registered uses of ethylene oxide already exist to sterilize hospital items; to treat processed spices 

and seasonings; and to treat commercial food processing, handling, and storage facilities. When used 

directly in the gaseous form or in non-explosive gaseous mixtures, ethylene oxide can act as a 

disinfectant, fumigant, sterilizing agent, and insecticide.

As of September 14, 2006, EPA’s Pesticide Document Management System contains 73 citations for 

efficacy data submitted on ethylene oxide products. We believe the efficacy of ethylene oxide against the 

target pests as described in this Section 18 application is well documented. 

EXPECTED RESIDUE LEVELS IN FOOD

(Residue data included as a separate attachment)

This is a nonfood/feed use that will be applied in a manner that will not contaminate food, feed, or water.
DISCUSSION OF RISK INFORMATION

(Potential risks to human health, endangered or threatened species, 

beneficial organisms, and the environment)

Description of application sites, including proximity to residential areas, aquatic systems, 

endangered or threatened species habitats, soil types, etc.:

When used as proposed on this Section 18 application, ethylene oxide would be used to sterilize the 

interior surfaces of self-enclosed animal isolator units. These animal isolator units are located within 

research areas of USDA APHIS veterinary research laboratories in Ames, Iowa. These laboratories are 

located inside the buildings. The composition of the compressed gas is 10% ethylene oxide and 90% 

freon. A freon monitor will be used to detect any potential leakage. Animal isolators are located in

negative pressure rooms in an animal containment facility. Floor drains lead to a wastewater 

pretreatment facility on site, but may be capped if necessary during the application of ethylene oxide to 

isolators.

EPA-registered uses of ethylene oxide already exist to sterilize hospital items; to treat processed spices 

and seasonings; and to treat commercial food processing, handling, and storage facilities. When used 

directly in the gaseous form or in non-explosive gaseous mixtures, ethylene oxide can act as a 

disinfectant, fumigant, sterilizing agent, and insecticide.

Possible risks posed by use: 

General risks: Pesticides have the potential to produce long-term damage to the environment if not used 

and disposed of in accordance with label instructions and other local, State and/or Federal statutes. 

However, damage to the environment from short-term use of pesticides during emergency pest

eradication and prevention campaigns is not expected because of their limited and infrequent use. 

If not used correctly according to all applicable label language concerning use, transport, handling and 

disposal, pressurized gas containers are potentially hazardous. 

Proposals to mitigate risks: 

A copy of the EPA-approved label, material safety data sheet, and technical information sheet for 

Oxyfume® 2000 is contained in appendix 2, 3, and 4, respectively. The product should only be handled 

and applied by persons experienced in Oxyfume® 2000 sterilization and fumigation. The product may be 

used only in facilities that meet the requirements of 29 CFR 1910.1047. The product may be used only by 

persons who have been trained in accordance with 29 CFR 1910.1047.

Personnel using ethylene oxide must receive annual Occupational Safety and Health Administration 

(OSHA) required training (Title 29, Code of Federal Regulations, Part 1910.1047). The individual 

adding sterilant gas to each isolator will wear a full-face, in-line supply respirator with a 5 or 10-minute 

escape bottle. A second individual serves as an observer immediately outside of the room where animal 

isolators are located. Although the need is not anticipated, this person is available to summon emergency 

assistance. This person is also required to receive annual ethylene oxide training. 

With strict adherence to the label's application instructions and applicable worker monitoring and safety 

requirements, the Environmental Protection Agency believes that, no unreasonable adverse health effects 

will occur from use of this chemical. 

Ethylene oxide personal breathing zone sampling using passive dosimetry will take place twice a year.

NOTE: Apply this product as specified by the Federal label and all application methods described 

under the terms of this quarantine exemption.
COORDINATION WITH OTHER AFFECTED FEDERAL, STATE, AND LOCAL AGENCIES

EPA regulates ethylene oxide under the Clean Air Act; Comprehensive Environmental Response, 

Compensation, and Liability Act; Federal Insecticide, Fungicide, and Rodenticide Act; Resource 

Conservation and Recovery Act; Superfund Amendments and Reauthorization Act; and the Toxic 

Substances Control Act. OSHA regulates ethylene oxide under Title 29, Code of Federal Regulations, 

Part 1910.1047.

Because of the limitations of the use proposed in this Section 18 application, no impacts to threatened or 

endangered species are anticipated. No coordination with the U.S. Fish and Wildlife Service is 

anticipated for this Section 18.

ACKNOWLEDGEMENT BY REGISTRANT

See appendix 5 for letter of acknowledgement from Oxyfume® 2000 manufacturer, Honeywell.

ENFORCEMENT PROGRAM

(Explanation of legal authority and program resources for enforcement)

Use data will be collected and reported as required to EPA per the requirements outlined in 40 CFR 

166.32. Treatments conducted out of compliance with applicable APHIS Veterinary Services

memoranda, directives, or legal authorities are reported to Veterinary Services to be addressed by 

management.

REPEAT USES

(If use being requested is a repeat use, and final report has not been filed, 

interim final report included as a separate attachment)

Interim and final report will be filed at the appropriate time.
NAME OF PEST(S)

Under the use described in this Section 18 application, the pesticide will be used to inactivate forms of 

microbial life in the inanimate environment, including all forms of vegetative bacteria, bacterial spores, 

fungi, fungal spores, and viruses.

ORIGIN OF INTRODUCED PEST(S)

Origin of pest, means of introduction, and spread into the area (if known):

The target pests described in this application are ubiquitous in the environment. It is not possible to 

determine the origins of the pests or the means of introduction. If not controlled by pesticides, the spread 

of the pests takes place via the defined reproductive mechanisms of the bacteria, fungi or virus.

IMPACT OF THE PEST

Anticipated impact of not controlling pest, and other information pertinent to economic importance 

of this pest: 

Gnotobiotic research at the NVSL and NADC consists primarily of the use of CDCD (cesarean derived –

colostrum deprived) pigs and calves. Raised in a germ-free animal isolator, the use of CDCD animals 

ensures scientists can focus on specific microbes, antibodies, metabolic pathways, and other criteria that 

impact on the diagnosis and control of animal diseases in the United States and abroad.

Without the ability to sterilize animal isolators, the NVSL and NADC are not able to conduct animal 

disease research as it relates to the diagnosis and control of these diseases.