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Significant New Alternatives Policy Program

Fire Extinguishing and Explosion Prevention Sector

Risk Screen on Substitutes for 

Total Flooding Systems in Unoccupied Spaces

Substitute: 2-bromo-3,3,3-trifluoropropene (2-BTP)

This risk screen does not contains Clean Air Act (CAA) Confidential Business Information (CBI) 

and, therefore, may be disclosed to the public.

1. INTRODUCTION

Ozone-depleting substances (ODS) are being phased out of production in response to a series of 

diplomatic and legislative efforts that have taken place over the past two decades, including the Montreal 

Protocol and the Clean Air Act Amendments of 1990 (CAAA). The U.S. Environmental Protection 

Agency (EPA), as authorized by Section 612 of the CAAA, administers the Significant New Alternatives 

Policy (SNAP) Program, which identifies acceptable and unacceptable substitutes for ODS in specific 

end-uses based on assessment of their health and environmental impacts. 

EPA’s decision on the acceptability of a substitute is based on the findings of a screening assessment of 

potential human health and environmental risks posed by the substitute in specific applications. EPA has 

already screened a large number of substitutes in many end-use applications within all of the major ODSusing sectors including: refrigeration and air conditioning, solvent cleaning, foam blowing, aerosols, fire 

suppression, adhesives, coatings and inks, and sterilization. The results of these risk screens are presented 

in a series of Background Documents that are available in EPA's docket.

The purpose of this report is to supplement EPA’s Background Document on the fire extinguishing and 

explosion protection sector (hereinafter referred to as the Background Document, EPA 1994a). This risk 

screen discusses the potential human health and environmental risks posed by 2-bromo-3,3,3-

trifluoropropene (hereinafter referred to as 2-BTP) when used as a flooding agent in unoccupied spaces as 

a replacement for Halon 1301. There are several aviation applications for this proposed substitute

including the protection of engine nacelles and auxiliary power units (APUs). Table 1 details the 

composition of the proposed substitute and its potential impurities prior to activation.

Table 1: Composition of 2-BTP and Potential Impurities

Component Chemical Formula CAS Number Concentration 

(Weight Percent)

2-bromo-3,3,3-trifluoropropene CF3CBr=CH2 1514-82-5 99.5%

Potential Impurities (maximum concentration)

1,2-dibromo-3,3,3-trifluoropropane C3H3Br2F3 431-21-0 ≤0.3%

3,3,3-trifluoropropyne C3HF3 661-54-1 ≤0.1%

3,3,3-trifluoropropene C3H3F3 677-21-4 ≤0.1%

Section 2 of this report summarizes the results of the risk screen for the proposed substitute for use in 

unoccupied spaces. The remainder of the report is organized into the following sections:
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 Section 3: Atmospheric Assessment

 Section 4: Volatile Organic Compound Assessment

 Section 5: Potential Health Effects

 Section 6: Occupational Exposure Assessment

 Section 7: General Population Exposure Assessment

 Section 8: References

2. SUMMARY OF RESULTS

EPA’s risk screen indicates that the use of the proposed substitute will be less harmful to the atmosphere 

than the continued use of ODS and substitutes used in this sector, such as HCFC Blend A, HFC-227ea,

and HFC-125, as it is less harmful to the ozone layer, has lower climate impact, and a shorter atmospheric 

lifetime. 2-BTP’s contributions to volatile organic compound (VOC) emissions are likely to be 

insignificant compared to VOC emissions from all other sources (i.e., both anthropogenic and biogenic).

EPA’s risk screen indicates that the use of the proposed substitute is not expected to pose a significant 

toxicity risk to personnel or the general population, specifically when the substitute is used on engine 

nacelles and APUs on aircraft and when proper engineering controls are employed during manufacturing 

activities. It is expected that procedures identified in the material data safety sheet (MSDS) for 2-BTP and 

good manufacturing practices will be adhered to, and that the appropriate safety and personal protective 

equipment (PPE) (e.g., protective gloves, tightly sealed goggles, protective work clothing, and suitable 

respiratory protection in case of accidental release or insufficient ventilation) consistent with OSHA 

guidelines will be used, as applicable, during manufacture and disposal of 2-BTP total flooding systems.

3. ATMOSPHERIC ASSESSMENT

This section presents an assessment of the potential risks to atmospheric integrity posed by the use of 2-

BTP as a total flooding fire extinguishing agent in unoccupied spaces. The proposed substitute is 

substantially less harmful to the ozone layer, has a lower climate impact and a shorter atmospheric 

lifetime compared to ODS (e.g., halon 1301). In addition, 2-BTP has a lower climate impact and shorter 

atmospheric lifetime than those predicted for other substitutes examined in the Background Document, as 

well as a commonly utilized substitutes. Thus, EPA believes that use of 2-BTP would result in 

substantially less harm to the climate and ozone layer than the continued use of ODS and commonly used 

ODS substitutes. 

Table 2: Atmospheric Impacts of 2-BTP Compared to Other Flooding Agents

Chemical ODP GWP (100-year) ALT (years)

Proposed Substitute

2-BTP 0.0028a 0.23 – 0.26b 7 daysa

Other Flooding Agents

Halon 1301 15.9c 7,140d 65d

HCFC Blend Ae 0.035c 1,546d NAf

HFC-227ea 0 3,220d 34.2d

HFC-125 0 3,500d 29d

a Patten et al. 2012

bGWP range represents GWPs for 30°N to 60°N and 60°S to 60°N emissions scenarios for a 100-year time horizon. A tropospherically wellmixed approximation of the GWP is equal to 0.59. (Patten et al. 2012)

cWMO (2010) 

d

IPCC 4th Assessment Report (Forster et al. 2007)

e HCFC Blend A is a blend consisting of HCFC-123 (4.75%), HCFC-22 (82%), HCFC-124 (9.5%), and D-limonene (3.75%).

f Atmospheric lifetimes are not given for blends because the components separate in the atmosphere. The ALT for HCFC-123 is 1.3 years, 

HCFC-22 is 12 years, HCFC-124 is 5.8 years, and D-limonene ranges from less than a minute to a few hours (IPCC 4th Assessment Report 

[Forster et al. 2007] and WHO 1998).
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4. VOLATILE ORGANIC COMPOUND (VOC) ANALYSIS

2-BTP is regulated as a VOC under CAA (40 CFR 51.100(s)). Through regulations and standard industry 

practices, emissions of 2-BTP should be controlled.

The submitter intends to manufacture 2-BTP as a total flooding agent in unoccupied spaces as a 

replacement for Halon 1301. An assessment was performed to compare the annual VOC emissions from 

the use of 2-BTP as total flooding agent to other anthropogenic sources of VOC emissions. Assuming the 

submitter’s maximum anticipated annual production of 2-BTP for all proposed fire suppression end-uses 

is entirely released (in the absence of controls), approximately [ ] of VOCs would be emitted. This is 

approximately equal to [ ] percent of all anthropogenic VOC emissions in the U.S. in 2014;

1 however, the 

release of total production for all proposed end-uses of 2-BTP is extremely unlikely to occur, as this 

would imply that all installed total flooding systems would be completely discharged in the same year. 

An additional analysis was performed to determine more realistic annual VOC emissions from the use of 

2-BTP in total flooding applications. Assuming the average annual release rate for total flooding

applications of 2.5% is applied to the entire intended U.S. annual production of 2-BTP, approximately [ ]

of VOCs would be emitted, which is approximately equal to [ ] percent of all anthropogenic VOC 

emissions in the United States.

Although the VOC emissions for these fire suppression applications are several orders of magnitude 

lower than other anthropogenic emissions, it is likely that the estimated VOC emissions estimated here 

can be further reduced. There are acceptable fire suppression agents currently in use that are VOCs (e.g., 

perfluoroketones), and thus, use of 2-BTP is not expected to increase VOC emissions relative to these 

other acceptable substitutes. Furthermore, most releases of 2-BTP are expected to be at altitude, not in the 

lower troposphere, and would contribute less to the VOC burden.

As the calculated annual releases of 2-BTP from these analyses are several orders of magnitude smaller 

than other anthropogenic sources of VOC emissions and because 2-BTP would not result in greater 

impacts on local air quality than other available options, EPA believes that through the use of regulations 

and standard industry practices, the environmental impacts of these VOCs are not considered a significant 

concern.

5. POTENTIAL HEALTH EFFECTS

As required for a new chemical, the manufacturer of this agent submitted a Toxic Substance Control Act 

(TSCA) Premanufacture Notice (PMN) for review by EPA. The PMN, designated as P-14-260, has 

completed EPA review and the manufacturer is presently subject to requirements contained in a TSCA 

section 5(e) Consent Order. Other future manufacturers and processors will be subject to a TSCA section 

5(a)(2) Significant New Use Rule (SNUR) that is expected to be promulgated in 2016. The requirements 

of the consent order apply to all commercial manufacturing, processing, distribution in commerce, use 

and disposal of 2-BTP, unless exempted; the SNUR would have similar or identical requirements to the 

consent order. The consent order requires use of 2-BTP for aircraft either 1) as a total flooding agent in 

engine nacelles and APUs on aircraft or 2) as a streaming agent in handheld extinguishers in aircraft. In 

addition, a manufacturer for this agent is required to maintain workplace airborne concentrations of 2-

BTP at or below a specified New Chemical Exposure Limit (“NCEL”) of 1 part per million (ppm), 

verified by exposure monitoring data; otherwise PPE (e.g., respirators) must be provided to workers to 

prevent inhalation exposure. EPA developed the NCEL for 2-BTP based on review of available toxicity 

studies (U.S. EPA, 2015b). The NCEL is the maximum 8-hour time weighted average (TWA) at which 

 

1 Based on the 2014 annual total VOC emissions for the United States (i.e., approximately 17.13x106 MT) as reported in the 

National Emissions Inventory (EPA 2015a).
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personnel in an occupational environment can be exposed regularly without adverse effects. The basis of 

the NCEL is long-term health effects (decreased postnatal survival and increased gestation length), and is 

not relevant to the acute exposure expected at end-use of the fire suppressant.

According to the MSDS, exposure to 2-BTP through ocular or dermal absorption is unlikely to cause 

irritation, and ingestion is not likely to occur in industrial use. However, the most likely pathway of 

exposure is through inhalation. Overexposure via inhalation to the proposed substitute may cause central 

nervous system effects, such as dizziness, confusion, physical incoordination, drowsiness, anesthesia, or 

unconsciousness. At concentrations of 1.0 percent or higher, the proposed substitute may cause increased 

sensitivity of the heart to adrenaline which might cause irregular heartbeats and possibly ventricular 

fibrillation or death. In the case that 2-BTP is inhaled, person(s) should be immediately removed and 

exposed to fresh air. The MSDS recommends that if breathing is difficult, person(s) should seek medical 

attention.

Short ocular, dermal, or ingestion exposures are not expected to pose a hazard. However, in case of ocular 

exposure, the MSDS for 2-BTP recommends that person(s) sHastings7hould immediately flush the eyes, 

including under the eyelids, with fresh water and move to a non-contaminated area. Medical attention 

should be sought if irritation develops or persists. In the case of dermal exposure to 2-BTP, the MSDS 

recommends that person(s) should immediately wash the affected area with large amounts of water and 

remove all contaminated clothing and footwear to avoid irritation. If water is not available, cover the 

affected area with a clean, soft cloth. Medical attention should be sought if irritation develops or persists. 

2-BTP is not likely to be hazardous by ingestion; however, in case of ingestion, the MSDS recommends 

the person(s) to consult a physician immediately. Do not induce vomiting without medical advice.

2-BTP vapors are heavier than air and cause suffocation by reducing oxygen available for breathing, 

causing asphyxiation in high concentrations. Such vapors pose a potential hazard if large volumes are 

trapped in enclosed or low places. If person(s) are exposed to high concentrations, the person(s) will 

likely not realize that he/she is suffocating, but may experience central nervous system effects, such as 

drowsiness and dizziness.

EPA’s review of the human health impacts of this proposed substitute is contained in the public docket 

for this decision. These risks and procedures after exposure are similar for other common fire 

suppressants. The potential health effects of 2-BTP are unlikely to occur when following good industrial 

hygiene practices and the PPE and engineering control (e.g., ventilation) recommendations outlined in the 

MSDS for 2-BTP, Sections 6 and 7 of this risk screen, and above.

6. OCCUPATIONAL EXPOSURE ASSESSMENT

The potential for personnel exposure to 2-BTP during manufacturing, installation and servicing are 

examined in this section. EPA has evaluated the risks associated with potential exposures to 2-BTP 

during production operations and the filling of fire extinguishers as well as in the case of an inadvertent 

discharge of the system during maintenance activities on the fire extinguishing system.

2-BTP is not expected to pose a risk to workers when the engineering controls and PPE recommendations 

referenced in the MSDS for this proposed substitute are followed. For operations requiring handling of 

the substitute, engineering controls should include adequate ventilation systems and enclosed or confined

operations to ensure exposure levels to the proposed substitute are below the NCEL. In general, use of 

appropriate PPE is recommended, specifically respirators during activities in which exposure to the 

proposed substitute cannot be controlled through other means. If the proposed substitute is handled in 

enclosed spaces where exposure limits might be exceeded, a self-contained breathing apparatus (SCBA) 

should be used. When handling a leak in a storage container, protective clothing is recommended as well 

as vapor-in air detection systems. If the presence of the proposed substitute is detected in the workplace 

atmosphere, there may be a need to purge the gas from the confined space (e.g., with air, water, or an inert 

gas followed by air), following by additional testing of the space to ensure the proposed substitute has
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been removed completely from the atmosphere. Furthermore, gloves (i.e., neoprene, polyvinyl chloride 

[PVC], or polyvinyl alcohol [PVA]) should be worn when handling equipment containing the proposed 

substitute for prolonged periods. The combination of appropriate engineering controls and the use of PPE 

will ensure exposure levels to the proposed substitute are below the NCEL.

6.1. Occupational Exposure during Manufacture

As described by the submitter, there is limited exposure to the product during manufacturing. Personnel 

monitoring data were collected during the process of filling a fire extinguisher inside a filling booth 

equipped with local exhaust ventilation of 13.2 ACH. Air sampling data taken at the extinguisher filling 

area resulted in a TWA exposure of 5.9 ppm (American Pacific 2015). This value takes into account 

measured exposures inside the fill booth and in the filling area (outside the booth). The fill booth was 

measured to have an approximate volume of 2 m3(70 ft3). The table below summarizes the air sampling 

results provided by the submitter.

Table 3. Occupational Exposure Assessment during Manufacturing

Proposed 

Substitute

Ventilation 

Rate (ACH)

TWA Exposure (ppm)a

NCEL

(ppm) Inside the Booth Filling Area 

(Outside Booth) Total Exposure

2-BTP [ ] [ ] [ ] [ ] 1

a The operator has exposure inside the booth for 7 percent of the time and 93 percent of the time in the surrounding area.

These estimated exposure values are greater than the NCEL of 1 ppm. To effectively mitigate potential 

occupational exposure and maintain average exposure levels below the NCEL, the manufacturing space 

should be equipped with specialized engineering controls and well ventilated with a local exhaust system 

and low-lying source ventilation. The sampling data provided by the submitter demonstrates that local 

exhaust ventilation greatly reduces exposure concentration inside the fill both and in the filling area 

(American Pacific 2015) and as such, additional mechanical ventilation above the values tested [ ] can 

further control exposure levels to achieve a value of 1 ppm or lower. Testing and monitoring of the 

workplace atmosphere should be conducted regularly to ensure it has not been contaminated with the 

proposed substitute or any other airborne workplace hazards. Additionally, an eye wash fountain and 

quick drench facilities must be close to the production area. Employees responsible for chemical 

processing should wear the appropriate PPE, such as protective gloves, tightly sealed goggles, protective 

work clothing, and suitable respiratory protection in case of accidental release or insufficient ventilation.

EPA believes if these engineering controls are employed, the appropriate occupational safety guidelines 

are adhered to, and appropriate PPE is used, significant occupational exposure during manufacture of 2-

BTP is not expected to occur.

6.2. Occupational Exposure during Installation and Servicing

Exposure to 2-BTP is not likely during installation or servicing of 2-BTP total flooding systems for 

engines and APUs. As indicated by the submitter, the risk of accidental activation of the fire 

extinguishing system while personnel are present near the protected space is highly unlikely if proper 

procedures are followed. Proper instructions on system installation and servicing included in manuals for 

the 2-BTP systems should be adhered to. 

The locations of the 2-BTP bottles in the engine and APU compartments will vary by airplane model. The 

engine bottles could be installed inside or outside the pressurized volume, but they are connected through 

piping to the engines. APU bottles are typically installed forward of the APU firewall, outside of the 

pressurized volume of the plane. The bottles are hermetically sealed and the piping system is pressure 

tested, mitigating the potential for any leak of 2-BTP from the system. In the case of an inadvertent 

discharge of the system during maintenance activities on the fire extinguishing system or surrounding 
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equipment, the cowl doors that would be open to allow access to the area will allow personnel to 

immediately egress and avoid exposure (American Pacific 2014b).

Protective gloves and tightly sealed goggles should be worn for installation and servicing activities, to 

protect workers in any event of potential discharge of the proposed substitute, accidental or otherwise. 

Filling or servicing operations should be performed in well-ventilated areas. If handling the material in 

poorly ventilated areas, use proper respiratory protection. Furthermore, maintenance procedures that 

provide specific instruction to prevent accidental discharge of 2-BTP systems can be found in the Boeing 

Aircraft Maintenance Manual (AMM) (American Pacific 2014b). 

7. GENERAL POPULATION EXPOSURE

2-BTP is not expected to cause a significant risk to human health in the general population when used as a 

total flooding fire extinguishing agent. The only general population exposure to 2-BTP anticipated will be 

during discharge of the total flooding system. Should releases during manufacturing operations occur, 

engineering controls should be used (e.g., carbon absorption scrubbers) to collect and prevent the release 

of the proposed substitute to the atmosphere. 2-BTP is not listed as a priority pollutant or toxic pollutant 

under the Clean Water Act. Disposal of 2-BTP total flooding systems is subject to local, state, and federal 

regulations, which ensure that releases of 2-BTP and water contaminated with 2-BTP are not be dumped 

into sewers, on the ground, or into any body of water, but rather taken to a wastewater treatment facility 

or disposed of properly. 2-BTP is not considered to be hazardous waste under EPA regulations 

implementing the Resource Conservation and Recovery Act. Disposal procedures as outlined in the 

proposed substitute’s MSDS and local, state, and federal regulations should be followed. EPA believes 

that by using proper engineering controls and by following disposal and containment recommendations 

outlined in the proposed substitute’s MSDS, exposure to 2-BTP is not expected to pose a significant 

toxicity risk to the general population. 

8. REFERENCES

ACGIH. 2004. The Documentation of the Threshold Limit Values and Biological Exposure Indices. 

American Conference of Governmental Industrial Hygienists. Available at: www.acgih.org. 

ACGIH. 2005. Guide to Occupational Exposure Values. American Conference of Governmental 

Industrial Hygienists.

ACGIH. 2006. Threshold Limit Values for Chemical Substances (TLV®-CS). Dennis Casserly, TLV®-

CS Committee, University of Houston at Clear Lake. American Conference of Governmental Industrial 

Hygienists. Available online at: http://www.acgih.org/tlv/03_TLV-CS-Update_AIHce06.pdf. 

American Pacific Corporation. 2013. 2-BTP for Use as a Fire Suppression Agent. Significant New 

Alternatives Policy Program Submission to the U.S. Environmental Protection Agency. December 2013.

American Pacific Corporation. 2014a. Response to Incompleteness Letter for 2-BTP for Use as a Fire 

Suppression Agent SNAP Submission. September 25, 2014.

American Pacific Corporation. 2014b. Response to Incompleteness Letter for 2-BTP for Use as a Fire 

Suppression Agent SNAP Submission. November 10, 2014.

American Pacific Corporation. 2015. Industrial Hygiene Assessment Report. Prepared by Ferguson Risk 

Management, LLC for American Pacific Corporation. July 20 and August 11, 2015. 
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CDC. 1997. Respiratory Protection Program Manual. Office of Health and Safety, Centers for Disease 

Control and Prevention. January 1997. 

Folland, C.K., T.R. Karl, J.R. Christy, R.A. Clarke, G.V. Gruza, J. Jouzel, M.E. Mann, J. Oerlemans, M.J. 

Salinger and S.-W. Wang, 2001: Observed Climate Variability and Change. In: Climate Change 2001: 

The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the 

Intergovernmental Panel on Climate Change [Houghton, J.T., Y. Ding, D.J. Griggs, M. Noguer, P.J. van 

der Linden, X. Dai, K. Maskell, and C.A. Johnson (eds.)]. Cambridge University Press, Cambridge, 

United Kingdom and New York, NY, USA. Available online at: 

http://www.grida.no/climate/ipcc_tar/wg1/pdf/wg1_tar-front.pdf

Forster, P., V. Ramaswamy, P. Artaxo, T. Berntsen, R. Betts, D.W. Fahey, J. Haywood, J. Lean, D.C. 

Lowe, G. Myhre, J. Nganga, R. Prinn, G. Raga, M. Schulz and R. Van Dorland. (2007). Errata. In: 

Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth 

Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. 

Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University 

Press, Cambridge, United Kingdom and New York, NY, USA. Available online at: 

http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-errata.pdf.

Institute of Medicine. 2000. Clearing the Air: Asthma and Indoor Air Exposures. Committee on the 

Assessment of Asthma and Indoor Air. Division of Health Promotion and Disease Prevention. Institute 

of Medicine National Academy Press. Washington, DC. 

National Academy of Sciences (NAS). 2007. Acute Exposure Guideline Levels for Selected Airborne 

Chemicals: Volume 6. Committee on Acute Exposure Guideline Levels, Committee on Toxicology, 

National Research Council. Available online at: http://www.nap.edu/catalog/12018.html.

NFPA. 2010. NFPA 2010. Standard for Fixed Aerosol Fire Extinguishing Systems. National Fire 

Protection Association. 

Orkin, V. L. 2004. Photochemical Properties of 2-bromo-3,3,3-trfluoropropene and semi-empirical kinetic 

estimates of its Global Impacts on the Atmosphere. Prepared by the National Institute of Standards and 

Technology Physical and Chemical Properties Division for American Pacific Corporation. July 2004.

OSHA. 2009. Fire Protection and Prevention. Occupational Safety & Health Administration. Available 

online at: https://www.osha.gov/dte/grant_materials/fy09/sh-18796-09/fireprotection.pdf.

Patten, K. O., V. G. Khamaganov, V. L. Orkin, S. L. Baughcum, and D. J. Wuebbles. 2012. Correction to 

“OH reaction rate constant, IR absorption spectrum, ozone depletion potentials and global warming 

potentials of 2-bromo-3,3,3-trifluoropropene,” J. Geophys. Res., 117, D22301.

U.S. EPA. 2015a. National Emissions Inventory (NEI) Air Pollutant Emissions Trends Data. Accessed 12

March 2015. Updated March 2015. Available at: http://www.epa.gov/ttnchie1/trends/.

U.S. EPA. 2015b. EPA Response to Comments Received from the Submitter of TSCA 

Premanufacture Notice (PMN) P-14-260 Regarding EPA's Risk Assessment and Derivation of the

Occupational Exposure Limit for the Chemical Substance Reported in P-14-260. April 20, 2015.

U.S. EPA. 2012. Acute Exposure Guidelines (AEGLs) Definitions. Available online at: 

http://www.epa.gov/oppt/aegl/pubs/define.htm.
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U.S. EPA. 1994a. Risk Screen on the Use of Substitutes for Class I Ozone-Depleting Substances: Fire 

Suppression and Explosion Protection (Halon Substitutes). Stratospheric Protection Division. March 

1994. 

U.S. EPA. 1994b. Methods for Derivation of Inhalation Reference Concentrations and Application of 

Inhalation Dosimetry. Environmental Criteria and Assessment Office, Office of Health and 

Environmental Assessment, Office of Research and Development, U.S. Environmental Protection 

Agency. EPA/600/8-90/066F. October 1994.

WHO (World Health Organization). 1998. Concise International Chemical Assessment Document 5 –

Limonene. Available online at: http://whqlibdoc.who.int/publications/1998/9241530057.pdf.

WMO (World Meteorological Organization). 2011. Scientific Assessment of Ozone Depletion: 2010, 

Global Ozone Research and Monitoring Project-Report No. 52, 516 pp., Geneva, Switzerland.