1 Section 18 Emergency Exemption Application

TYPE OF EXEMPTION BEING REQUESTED

 SPECIFIC

 QUARANTINE

 PUBLIC HEALTH

CONTACT PERSON(S) AND QUALIF IED EXPERT(S) (166.20(a)(1))

CONTACT PERSON:

Name: David Hickens

Title: Chief, NASA JSC Environmental

Office

Organization: NASA JSC

Address:

Phone: 281-483-3120 QUALIFIED EXPERT:

Name: Mark E. Wilson

Title: Boeing Associate Technical Fellow

Organization: Boeing

Address: 3100 space Center Blvd., MC HB3- 20, Houston TX 77059-3556

Phone: 281-226-6966

DESCRIPTION OF PESTICIDES REQUESTED (166.2O(a)(2))

Common Chemical Names (Active Ingredients): o-phthalaldehyde (OPA ) CAS Number 643-79-8

Trade Names and EPA Reg. Nos.:

Formulations: Immobilization of OPA on a Porous Resin (P/N SV1012327-2) % Active Ingredient: 0.25 g OPA/cm 3 of resin; Resin Loading factor based on 84% elution efficiency = 210 mg OPA/cm 3 resin

Manufacturers: o-phthalaldehyde – Sigma Aldric h; OPA Resin (P/N SV1012327-2) –

Hamilton Sundstrand2 DESCRIPTION OF PROPOSED USE (166.20(a)(3))

Sites to be Treated: International Space Station Internal Active Thermal Control System (IATCS) coolant including the US Laboratory including Node 1 and Airlock (249 liters), Japanese Experiment Module (213 liters), Colum bus (160 liters), and Node 3 (194 liters).

Method of Application: Elution of OPA from the OPA Resin (P/N SV1012327-2) into the IATCS coolant volume through the use of an antimicrobial applicator canister (P/N 683- 63436) placed in a by-pass line at a payload rack location and in itiating flow at 400 lb/hr for

16 hours.

Rate of Application (in terms of a.i. and product): Approximately 250 mg/L OPA added to each loop approximately 1/year.

Maximum Number of Applications: Approximately 1 application/year for each loop, determined by measuring OPA conc entration every 90 days and ut ilization of the quantity of OPA Resin necessary to increase the as circulat ed in flight hardware OPA concentration to 300 ppm based on degradation of OPA to 50 – 100 ppm.

Total Acreage (or other units) to be Treated: US Laboratory - 272 liters, Japanese Experiment Module – 213 liters, Columbus – 150 liters, and Node 3 – 194 liters for a total

volume of 829 liters.

Total Amount of Pesticide to be Used (in terms of a.i. and product): V R = Volume Resin Required; V L = Volume of IATCS (L); [OPA] = Desired OPA Concentration (mg/L); F OPA = OPA Resin Loading factor = 210 mg OPA/cm 3 -Resin; Therefore V R = (V L * [OPA])/ F OPA ; V R = (829 L * 250 mg/L)/210 mg OPA/cm 3 = 987 cm 3 OPA Resin/year.

Use Season (period of time for wh ich use of chemical is requested): As required through the life of the International Space Station to ma intain the OPA concentration as circulated in flight hardware between 25 – 500 ppm OPA as sp ecified in Table 4.1-2.8 “Heat transport fluid (IATC)” Revision E of SSP-30573 “Space Stati on Program Fluid Procurement and Use Control Specification”.

Additional Restrictions, User Precautions and Requirements, Qualifications of Applicators, etc.: The method to deliver OPA to the IATCS coolant was an immobilization

of the active biocide to a solid substrate. The immobilization process involved a solvent evaporation technique that allowed the OPA to be physically cons trained in a porous methacrylate resin material. Once the resin materi al was exposed to the coolant fluid, the OPA effectively eluted from the resin material in to the aqueous phase. This implementation was selected due to system requirements and the use of pre-existing flig ht hardware. System requirements included limits on the initial and final OPA concentration observed eluting from the canister (reactor) and compatibility with the coolant loop chemistry (i.e. no leachate, particles, adverse effects to chemistry/system materials). The flight hardware used for the OPA delivery was a stainless steel canister with an approximate volume of 2.0 L with flex hoses and quick disconnects to connect th e canister to a payload rack location.3 ALTERNATIVE METHODS OF CONTROL (166.20( a)(4)) (Efficacy data and/or other information included as a separate attachment)

Registered Alternative Pesticides: An extensive evaluation of biocides was conducted to

down-select to several candidates for test trials (see Appendix A). Criteri a for that down-select included: the need for safe, non-intrusive im plementation and operation in a functioning system; the ability to control existing plankt onic and biofilm residi ng micro-organisms; a negligible impact on system wetted materials of construction; and a negligible reactivity with existing coolant additives. A five-point or dinal rating scale from 5 (excellent) to 1 (unacceptable) was used to score each biocid e against 10 weighted assessment criteria: Material Compatibility 4x; Chemical Compa tibility 3x; Safety/Toxicity 3x; Disinfection Effectiveness 2x; Stability 2x; Byproduct Accepta bility 2x; On-orbit Implementation 1x; Cost 1x; In-Flight Monitoring 1x; and Technology Re adiness 1x. All oxidizing biocides and halogens were eliminated due to increased corro sion of nickel brazes on cold plates and heat exchangers. Phenols were eliminated due to instability in the coolant. Quaternary

ammoniums were eliminated due to their reducti on of surface tension which increases gas trap leakage. Trade studies and rapid screening assays were used to develop a prioritized list of acceptable antimicrobial agents including glut araldehyde, ortho-phthalaldehyde (OPA), and methyl isothiazolone. Glutaraldehyde at great er than 25 ppm was eliminated due to NASA concerns with safety and toxicity and methyl isothiazolone was eliminated from further consideration due to its ineffectiveness against biofilms and toxicity at higher concentrations. Therefore, OPA, an aromatic dial dehyde compound with the formula C 6 H 4 (CHO) 2 was selected for qualification testing fo r use as a biocide in the IATCS.

Alternative Control Practices: Lowering the water activity of the coolant by increasing salt concentration was ruled out due to requireme nts for surface tension specified in SSP-30573 Revision B, Space Station Program Fluid Proc urement and Use Control Specification. Requirement specifications included chloride s less than 1.0 ppm and a surface tension of 72– 77 dynes/cm at 20  C.

EFFICACY OF USE PROPOSED UNDER SE CTION 18 (166.20(a)(5)) (Efficacy data

and/or other information include d as a separate attachment)

EXPECTED RESIDUE LEVELS IN FOOD (166.20(a)(6)) (Residue data included as separate attachment) Not Applicable Due to Removal by ISS ECLSS

DISCUSSION OF RISK IN FORMATION (166.20(1)(7)) (Potential risks to human health, endangered or threatened species, beneficial organisms, and the environment)

Description of application sites, including proximity to reside ntial areas, aquatic systems, endangered or threatened habitats, soil types, etc.: Elution of OPA from the OPA Resin (P/N SV1012327-2) into the IATC S coolant volume through the use of an antimicrobial applicator canister (P/N 683-63436) placed in a by-pass line at a payload rack location in the U.S. Laboratory Module, Columbus Module, Ja panese Experiment Module, and/or Node 3 and initiating flow at 400 lb/hr for 16 hours.4 Possible risks posed by use: Evaluations of the toxicity of OPA were conducted by Martin E. Coleman, Ph.D., Wyle Toxicology Consulta nt, and the results were reported in Memo 632 dated March 4, 2005, Memorandum TOX-MC -2007-Draft dated August 27, 2007 and

Memorandum TOX-MC-2008-Draft dated March 24, 2008. Circulated concentrations of OPA up to 500 ppm were determined to be Toxicity Hazard Level 0 (Nonhazard) defined as slight

irritation that lasts <30 minutes and will not require therapy for all toxicology parameters.

Initial effluent concentrati ons of OPA greater than 1000 ppm introduced into a payload bypass stream from the antimicrobial applicator we re determined to be a Toxicity Hazard Level 1 (Critical) defined as slight to moderate ir ritation that lasts >30 minutes and will require therapy due to irritation of soft tissues such as the eye. If coolant containing OPA leaks and the water evaporated until OPA became saturated, the resulting concentrate would be a severe eye irritant classified as a Toxicity Hazard Level 2 defined as moderate to severe irritation that has the potential for long-term performance d ecrement and will require therapy. Solid OPA was determined to be a Toxicity Hazard Level 2 (Catastrophic) for eye a nd skin irritancy and a Toxicity Hazard Level 1 (Critical) for inhala tional and systemic toxicity. OPA in rare instances has caused allergic r eactions from repeated skin c ontact with residual liquids or solids. OPA loaded resin beads containing 0.25 g/cm 2 OPA in the antimicrobial applicator was assessed as a Toxicity Hazard Level 0 (Nonhazard).

JSC Toxicology provided additional assessment of the risk of solid OPA from IATCS fluid in Memo Tox-HG-2009-09 dated April 30, 2009. This memo documents the JSC Toxicology Group's assessment of dry OPA from evaporated ITCS fluid as a Toxicity Hazard Level 0, rather than a Toxicity Hazard Level 2. A lthough solid OPA could cause catastrophic eye damage if it were to contact the eye, consideration of the behavi or of liquids under the specific spaceflight conditions expected on ISS led to the conclusion that contact with the eyes of dry OPA from evaporated ITCS fluid is not cred ible. Thus, dried OPA films from evaporated

ITCS fluid should not be considered Toxicity Hazard Level 2 eye hazards.

JSC Toxicology recommended that leaks from th e antimicrobial applicator and the IATCS should be quickly removed before evaporation occurs. Leakage detection on-orb it is primarily based on thermal control system accumulator quantities.

Proposals to mitigate risks: A removal resin was developed to be able to remove OPA from

the IATCS in the event of a sust ained leak to preserve crew h ealth and safety or if adverse system effects were detected from OPA utilization. Ambersorb 572 ® was chosen as the flight candidate since it had approxima tely twice the capacity for OPA than the activated carbon. The resin material has a much more porous stru cture, resulting in higher surface area to facilitate organic adsorption. The resin was al so shown to remove gr eater than 95% of OPA degradation products from IATC S coolant but it has a higher affinity for free OPA. The removal resin canister may be attached at a pa yload rack location similar to antimicrobial applicator.

COORDINATION WITH OTHER AFFECTED FEDERAL, STATE, AND LOCAL AGENCIES (166.20( a)(8))

Not Applicable5 NOTIFICATION OF REGISTRANT (166.20(a)(9))

ENFORCEMENT PROGRAM (166.20(a)(10)) (Exp lanation of legal authority and program resources for enforcement)

REPEAT USES (166.20(a)(11)) (If use being requested is a repeat use, and final report has not been filed, interim final report included as a separate attachment)

PROGRESS TOWARD REGISTRATION (166.25(b)(2)( ii) (Information from registrant concerning the current status ) (Not Required for Request for a Quarantine Exemption)

NASA is beginning the re gistration process.

NAME OF PEST (166.20(c)(I))

Scientific Name: Cupriavidus metallidurans, Va riovorax paradoxus, Acidovorax sp.

, Sphingomonas parapaucimobilis, Stenotrophomonas maltophilia, Methylobacterium

extorquens

, and Unidentified Gram Negative Rods

Common Name: Aerobic/Microaerophilic Water Bacteria

ORIGIN OF INTRODUCED PEST (166.20(c)(2))

Origin of pest, means of its introduction , and spread into the area (if known):
The primary source of bacteria was from the dei onized water used to make the coolant for the Internal Active Thermal Control System. Als o, the equipment was chemically cleaned with isopropanol, rinsed with deionize d water and dried prior to asse mbly. The bacteria may also have been introduced during handling and assembl y. A silver salt biocide, silver sulfate, initially used as an additive in the coolant fo rmulation at a concentra tion of 0.1 – 3 parts per million (ppm) to control growth and proliferation of microorganisms rapidly decreased below

detection limits within a few hours. Silver ions rapidly underwent an oxidation reduction reaction with nickel. The rapid reduction of silver ions in the coolant created a favorable environment for the growth and proliferation of microorganisms. Counts of heterotrophic bacteria increased from <10 colony forming uni ts (CFU)/100 milliliters (ml) to greater than

1.0E+06 CFU/100 ml.6 IMPACT OF THE PEST (166.20(C)(3))

Anticipated impact of not controlling the pest, and other information pertinent to economic importance of this pest:
Uncontrolled microbiological growth in the IA TCS can deteriorate the performance of the system and potentially impact human health if opportunistic pathogens b ecome established in the system. Microorganisms are capable of degrading the coolant chemistry, attaching to surfaces and forming biofilm, subsequent biofoul ing of filters, tubing, and pumps, decreasing flow rates, reducing heat tran sfer, initiation and acceleration of corrosion, and enhanced

mineral scale formation. Disinfection to control microbiological growth and biofilm formation is necessary to maintain tolerable ri sk levels for the ISS IATCS due to the required operational life of the ISS IATCS for over 15 year s without the ability to periodically flush and replace coolant, sterilize the syst em, and/or replace system equipment.

Information Required for a Final Report

SAMPLE SECTION 18 EMERGENCY EXEMPT ION FINAL REPORT FORMAT (40 CFR 166.32)

(1) Total acreage, number of structures or ot her units treated, and th e total quantity of the pesticide used (either actual or estimated); (2) A discussion of the effectiveness of the pesticide in dealing with the emergency condition; the minimum inhibitory concentration (MIC) for OPA against the bacteria in the IATCS is 10 – 20 ppm. The minimum lethal concentration (MLC) for OPA against most of the identified bacteria in the IATCS is 30 – 50 ppm. However, the MLC of OPA against Methylobacterium

extorquens was determined to be 150 – 200 ppm. Expected use concentration of 300 ppm OPA is more than ten times higher than the MIC. And provides effective disinfection and microbiological growth control. (3) A description of any unexpect ed adverse effects which resulte d from use of the pesticide under the exemption; (4) The results of any monitoring required and/or carried out under the exemption; (5) A discussion of any enforcement actions taken in connection w ith the exemption; (6) Method(s) of disposition of a food or animal feed, if requi red to be destroyed under an exemption; and (7) Any other information requested by the Admini strator, such as the type of PPE worn by applicators.7 FIFRA SPECIFIC USE EXEMPTION - INTERIM REPORT

(1) Total acreage, number of structures or other units treated, and the total quantity of the pesticide used (either actual or estimated) – Samples of Internal Active Thermal Control System (IATCS) coolant were collected from tr eated units on the International Space Station (ISS) during January and February 2014. The IATCS samples were returned to ground on Space X-3 for analyses including OPA con centration and heterotrophic bacteria enumeration. The concentrations of o-phthala ldehyde (OPA) in the Japanese Experiment Module = 87.5 ppm, Columbus = 92.4 ppm, Node 3 = 181 ppm, and US Laboratory = 369 ppm. A canister containing 295 cm 3 OPA resin was applied to the Japanese Experiment Module on 2/27/2014 to provide a ta rget OPA concentration of 400 ppm in the coolant. The actual measured concentration in the Japanese Experiment Module after OPA application on 02/27/2014 was 388 ppm. The US La boratory was also re-filled with 3.6 L of coolant containing 100 ppm OPA on January 31, 2014. The th eoretical increase in OPA concentration in the US Laboratory from the coolant re-additio n is approximately 1.5 ppm. A total volume of

530 cm 3 of OPA resin has been loaded into 2 canisters that are already on ISS for planned readditions of OPA to Columbus and Node 3. A canister containing 235 cm 3 of OPA resin is anticipated to resupply Columbus with a pproximately 385 ppm OPA in January 2015. A second canister containing 295 cm 3 will be used to resupply Node 3 with approximately 340 ppm OPA. This treatment pl an is in compliance with th e EPA exemption 11DO01 which limits OPA in each treated unit to 50 – 500 ppm, limits application of OPA to each loop to once per year, and limits the volum e of OPA resin/year to 1974 cm 3

.

(2) A discussion of the effectiveness of the pest icide in dealing with the emergency condition

- The minimum inhibitory concentration (MIC) for OPA against the bacteria in the IATCS is 10 – 20 ppm. The minimum lethal concentration (MLC) for OPA against most of the identified bacteria in the IATCS is 30 – 50 ppm. However, the MLC of OPA against Methylobacterium

extorquens was determined to be 150 – 200 ppm. The use concentration of 300 - 400 ppm OPA is more than ten times higher than th e MIC and provided effective disinfection and microbiological growth control which has consis tently been verified in return to ground samples with 7 day counts for heterotrophic bacteria on R2A agar at 28  C. Heterotrophic

bacteria counts in all of the treated IATCS c oolant samples collected from January - February 2014 and returned on Space X-3 were <10 colony fo rming units (CFU)/100 mL. This indicates that OPA has provided the proper level of di sinfection and is effective at controlling microbiological growth.

(3) A description of any unexpected adverse effect s which resulted from use of the pesticide under the exemption – There have been no unexpected adve rse effects resulting from the use

of OPA in the ISS IATCS coolant.

(4) The results of any monitoring required and/or carried out under the exemption – As discussed above in response to reporting the total qua ntity of OPA used during the year, return to ground samples are collected and returned to ground once per year and OPA concentrations in each loop are determined every 180 days on- orbit using a rapid colorimetric test strip. During the period from 04/15/2013 to 04/15/2014, OPA concentrations in all treated unties have remained from 50 – 500 ppm. The graph below documents the historical on-orbit OPA concentrations for all of the treated loops.8 (5) A discussion of any enforcement actions taken in connection with the exemption – No enforcement action was required during the 04/15/2013 to 04/15/2014 exemption period other than compliance with the guidelines identified in Exemption 11DO01. The use of OPA resin was limited to operations per SSP 30573 “Space St ation Program Fluid Procurement and Use Control Specification”, limitation of crew exposure through the use of personal protective equipment including protective eyewear and chemi cal resistant gloves, clean-up of leaks or spills, periodic OPA concentration meas urement, and historical documentation.

(6) Method(s) of disposition of a food or animal feed, if requi red to be destroyed under an exemption – None/Not applicable.

(7) Any other information requested by the Administ rator, such as the type of PPE worn by applicators – All applicable	directions,	restrictions,	precautions	and	MSDS	instr uctions

were	adhered	to	and	followed to ensure crew safety. Crew wear chemical resistant gloves, safety glasses, and use splash shields to prot ect eyes and skin from contact with OPA during loop applications. OPA is eluted from the re sin by placement in an unoccupied by-pass line in a payload rack and initiating flow. Eluted concentrations of OPA <1000 ppm are quickly diluted in minutes to 50 – 500 ppm OPA through mixing during circulation.