# STANDARD REVIEW ENGINEERING REPORT



# P-07-0601

ENGINEER: Maj’d El-Zoobi

PV (kg/yr):

SUBMITTER:

USE:TABLE 1: EXPOSURE SUMMARY FOR P-07-601**Vapor Inhalation** **Exposure concentration** **Supply Chain Component** **Scenario Assessment Basis** **No. of Sites** **No. of Workers** **Days / Yr Hrs / Day** **Mg/m^3 ppm** **Vapor Inhalation** **Exposure Dose** **Mg/day**•••MANUFACTURING EXPOSURE:Presentation of the Results of the Study and Comparison With the Current Assessment:Inhalation Exposure Concentration Assessed ValuesCEB’s Current Assessment Submitter Inhalation MonitoringStudyWorkerActivity8 hr TWAExposureconcentration (ppm)Comments 8 hr TWAExposureconcentration (ppm)CommentsOther Available Inhalation Exposure Concentration DataWorkerActivityCEB Data Submitter DataChemicalOperatorCylinder VentOperatorFreon Cylindervent OperatorAreasamplesPersonalsamplesNote (1): Table A-6, “Summary of Personal Occupational Exposure Monitoring Data for”, Occupational Exposure AndEnvironmental Release Data for, PEI Associates, 1990.The vapor pressure and boiling point of (the GS basis),mmHg and C, are comparable to the corresponding values for theNCS, which are mmHg and C, respectively. Hence the GS data is valid for comparison purposes.Servicing of MACs:Three documents containing occupational exposure data and information covering the servicing ofwere made available by CCD for CEB’s review. These documents comprised, first, a publiclyavailable journal article by J. Jetter of EPA that was included in the original PMN submission,second, a monitoring study for at in the US, and third, a risk analysis for bythe . The following is a discussion of these data sources.“Fault Tree Analysis for Exposure to in the United States”,J. Jetter, US EPA:This article was published in 2001 in Risk Analysis, and was included as part of the original PMNsubmission.This article describes a scenario where that the is aware of.This scenario is not considered to be routinebecause the is aware of what hasoccurred, takes action to mitigate the situation, and does not proceed to continue in his routinework unaware of what has occurred while being exposed to the resulting higher exposureconcentration.“Personal Air Sampling For in the US”:This is a monitoring study conducted by a third party for , who is not the PMN submitter.This study covered monitoring in service shops in the throughout the US. It was not utilized forthe following reasons:1.The study design called for 24 samples but only 13 were obtained, indicating a possibleinadequacy in whether the study is representative.2.The accuracy of some of the results are in question because break-through occurred insome of the samples.3.The study design may have resulted in inherent bias in that the shops that were sampledagreed on this beforehand. This issue is indicated in the study conclusion as well.Themean and highest concentrations wereppm and ppm, respectively. The assessedconcentration, based on PEI (1990), isppm(the GS value ofppmwas not utilized because itcovers a scenario of intentional environment, which is currentlydisallowed by clean air act rules). Given the study deficiencies described above, and given thatthe maximum value and the assessed value are in the same order of magnitude, the assessed valuewas considered to be a more accurate measure of exposure. It is noted that the vapor pressure of, the basis of the GS estimate, which is mmHg, is greater than that of the NCS.“Risk Assessment for Alternative Refrigerant HFO-1234yf”This is the only document among the three that covers the PMN substance. The scenarios that werecovered in this document and the rational for including or excluding them from the exposureassessment are given below:Occupational Exposure Scenario Rational for Acceptance orExclusionEquipment Rupture in ShopExcluded because it is not aroutine event since the work wouldcease after the event andmitigation would occur.Large Unnoticed LeakAccepted. Since it is unnoticed,the technician continues to workand is exposed to the resultingambient concentration.Flammable mixture is formed Not typically covered in the NCprogram.