Post on 26-Mar-2015
EtO MONITORING REQUIREMENTS
EtO MONITORING EQUIPMENT
Michael D. Shaw
Presented By
AnproleneDihydrooxirene
Dimethylene Oxide1,2-Epoxyethane
Oxacyclopropane Oxane
Oxidoethane ,-Oxidoethane
Oxiran Oxirane
ETHYLENE OXIDE
EtO HEALTH EFFECTS
Although there are limited studies in humans to directly link EtO to human cancers, there is sufficient evidence in experimental animals to conclude that ethylene oxide is carcinogenic to humans
Inhalation causes nausea, vomiting, neurological disorders and in some cases death
Traces of gas in gloves or clothing may cause burns
Residues in vascular catheters can cause thrombophlebitiswhereas in endotracheal tubes, tracheitis
Mortality of workers exposed to ethylene oxide: extended follow up of a British cohort.
Coggon D, Harris EC, Poole J, Palmer KT.MRC Environmental Epidemiology Unit, University of Southampton, UK.
Occup Environ Med. 2004 Apr;61(4):358-62
EVENTEVENT OBSERVEDOBSERVED EXPECTEDEXPECTED
DeathsDeaths 565565 607.6607.6
All cancersAll cancers 188188 184.2184.2
Stomach cancerStomach cancer 1010 11.611.6
Breast cancerBreast cancer 1111 13.213.2
Non-Hodgkin's Non-Hodgkin's lymphomalymphoma
77 4.84.8
LeukemiaLeukemia 55 4.64.6
AIMS: To obtain further information about the risks of cancer associated with occupational exposure to ethylene oxide
METHODS: Follow up was extended by 13 years for a cohort of 2876 men and women with definite or potential exposure to ethylene oxide in the chemical industry or in hospital sterilizing units
RESULTS: Analysis was based on 565 deaths, of which 339 had occurred during the additional period of follow up. Mortality was close to or below expectation for all causes
Occupational Exposure Standards
OSHA Standards
The TWA (8-hour time-weighted average) is 1 ppm
The Excursion Limit is 5 ppm, as averaged over a sampling period of 15 minutes
The Action Level is 0.5 ppm, calculated as an 8-hour time-weighted average
OSHA Regulations per 29 CFR 1910.1047
1910.1047(d)(1)(i)Determinations of employee exposure shall be made from breathing zone air samples that are representative of the 8-hour TWA and 15-minute short-term exposures of each employee
1910.1047(d)(3)(i)If employee exposure ≥ action level but ≤ the 8-hour TWA, repeat monitoring for each such employee at least every 6 months
1910.1047(d)(3)(ii)If employee exposure > 8-hour TWA, repeat monitoring for each such employee at least every 3 months
1910.1047(d)(6)(i)Monitoring shall be accurate, to a confidence level of 95%, to within ± 25% for airborne concentrations of EtO at the 1 ppm TWA and to within ± 35% for airborne concentrations of EtO at the action level of 0.5 ppm
1910.1047(d)(6)(ii)Monitoring shall be accurate, to a confidence level of 95%, to within plus or minus 35% airborne concentrations of EtO at the 5 ppm excursion limit
1910.1047(d)(7)(i)After 15 days, must notify affected employee of these results in writing
1910.1047(e)(1)Regulated area required wherever EtO may exceed the TWA
1910.1047(e)(2)Access to regulated areas shall be limited to authorized persons
1910.1047(i)(1)(i)(A)Medical surveillance program required for all employees who are or may be exposed to EtO at or above the action level, without regard to the use of respirators, for at least 30 days a year
1910.1047(j)(1)(i)Signage required (regulated areas)
DANGERETHYLENE OXIDE
CANCER HAZARD AND REPRODUCTIVE HAZARDAUTHORIZED PERSONNEL ONLY
RESPIRATORS AND PROTECTIVE CLOTHING MAY BE REQUIREDTO BE WORN IN THIS AREA
1910.1047(j)(1)(ii)(A)And on containers
DANGERCONTAINS ETHYLENE OXIDE
CANCER HAZARD AND REPRODUCTIVE HAZARD
1910.1047(k)(2)(iii)The employer shall keep an accurate record for 30 years IAW 29 CFR 1910.1020 of all measurements taken to monitor employee exposure to EtO
The date of measurementThe operation involving exposure to EtO which is being monitoredSampling and analytical methods used and evidence of their accuracyNumber, duration, and results of samples takenType of protective devices worn, if any Name, social security number and exposure of the employees whose exposures are represented
This includes:
ACGIH (American Conference of Governmental Industrial Hygienists) Threshold Limit Values
8 hr Time Weighted Average (TWA): 1 ppm
“A2” Suspected human carcinogen
ACGIH EQUIVOCATION
Threshold Limit Values (TLVs®) and Biological Exposure Indices(BEIs®) are determinations made by a voluntary body of independent knowledgeable individuals
TLVs® and BEIs® are not standards. They are guidelines designed for use by industrial hygienists in making decisions regarding safe levels of exposure to various chemical substances and physicalagents found in the workplace
Since TLVs® and BEIs® are based solely on health factors
There is no consideration given to economic or technical feasibility
NIOSH Recommendations
REL’s (Recommended Exposure Limit)
10 Hr Time-Weighted Average: <0.1 ppm
10 min/day ceiling value: 5 ppm
NIOSH considers ethylene oxide to be a potential occupational carcinogen
MONITORING FOR ETHYLENE OXIDE
TOXIC GAS MONITORING PRECEPTS—AS APPLIED TO ETHYLENE OXIDE
The most important precept in ANY toxic gas monitoring application isprotecting the employees
First priority—you must monitor where people are working
Additional considerations
Note that these precepts relate to CONTINUOUS monitoring Portable, survey monitoring has little applicability here, other than
for initial testing or backup purposes
The sterilizers and aeratorsDrain areasGas cylinder storage areaVentilation characteristicsAny other leakage or exposure possibilities
MONITORING METHODOLOGIES
Semiconductor Sensor (Solid State)
Inadequate sensitivity and no specificity
Possible application for catastrophic leak detection
Completely outmoded and outdated
What about occupational health?
Photoionization Detector (PID)
Responds to all organics so a chromatographic column must be used to remove interferences
More commonly known as GC or gas chromatography method
Advantage—Excellent interference rejection, but if used in the presence of isopropyl alcohol, will consume columns at an alarming rate
Disadvantage—Not true continuous monitoring
Disadvantage—Expensive
Advantage—Conventionally deployed stream-switching many pointseven if this precludes meaningful data collection
“Electrochemical” Voltammetric Sensor
Advantage—Excellent sensitivity, and good interference rejection to all but isopropyl alcohol (IPA)
Solution to this is replacement of IPA with phenol-based germicide or temporary analyzer pump shut-off while area is being wiped down with IPA
Advantage—True continuous monitoring at all points, facilitating meaningful data acquisition
Advantage—Not expensive for majority of applications
Disadvantage—Can become costly in those few “industrial sterilization”applications that really need to monitor scores of points
IMPORTANCE OF DATA ACQUISITION ARCHIVING/REPORTING
Even if you've been a good corporate citizen, and have installed sensorsfor toxic compounds all around your facility, to protect your employees…
Can you document long-term employee exposure?
Do you have any idea how close their exposure is to the allowable levels?
High concentration alarms are fine, but they're not enough!!
You can’t disregard long-term low level exposure
Unless you have a documented record of exposure, if you're sued, you'll be scrambling for data, desperately trying to re-create the past
the kind of exposure that lawsuits are based on
WHAT ABOUT BADGES?
Badges only offer an appreciation of employee exposure retrospectively
Inability to alarm at an instantaneous concentration value
An absence of time-history
A rounded "single number" value often insufficientto generate a realistic assessment of exposure levels
To know what's happening in real time!
Shortcomings include but are not limited to:
What’s the solution?
SOME ETHYLENE OXIDE MONITORING PRODUCTS
OFFERED BY
PORTABLE ANALYZER
CONTINUOUS MONITORING SYSTEMSINGLE POINT APPLICATION
CONTINUOUS MONITORING SYSTEMTWO POINT APPLICATION
CONTINUOUS MONITORING SYSTEMMULTI-POINT (THREE OR MORE) APPLICATION
ARC-MAX® DATA ACQUISITION, ARCHIVING,
AND REPORTING
ARC-MAX® MAIN SCREEN
ARC-MAX® SHIFT REPORT
ARC-MAX® TRENDING
ARC-MAX® ALARM LOG
CONCLUDING REMARKS
IT WOULD APPEAR THAT ETHYLENE OXIDE CARCINOGENCITY HAS BEEN OVER-TOUTED
REGULATIONS / RECOMMENDATIONS VARY BETWEEN OSHA, NIOSH, AND ACGIH
MAINTAINING A GOOD RECORD OF EMPLOYEE EXPOSUREIS CRUCIAL FOR DEFENSE PURPOSES
SPECIAL THANKS TO JOE HADLEYAND THE MEMBERSHIP OF EOSA