Friday, September 24, 2010


The AN74i operator exposure study1, executed by Andersen
Scientific, Inc., was performed to establish the average Ethylene
Oxide (EO) concentration within the immediate vicinity of the
AN74i sterilizer upon opening and unloading the sterilization bag.
Operator monitoring was performed using an AirScan® exposure
badge and by direct air analysis of collected air samples using a
gas-sampling pump and collection bag with a self-sealing septum
(Andersen Sniffer™). The contents of the gas-sampling
bags were quantitatively analyzed using gas chromatography,
the most sensitive Ethylene Oxide detection device available.
AN74i Sterilizer
Andersen Sniffer™ with nylon gas sampling bags
Shimadzu gas chromatograph and detector
AN92 15-minute STEL AirScan® badges
PAN-TY cable ties and Thomas & Betts cable tie tool
Standard load:
• 10 AN10 Andersen tubes sealed in 4.5” Polyethylene/Polysurlyn
• 2 Patient Gowns wrapped in CSR wrap
• 1 AN42 Sump Pump® wrapped in CSR wrap
• 6 Pairs of Latex Gloves sealed in Seal and Peel
• 10 Cotton-Tipped Applicators sealed in Seal and Peel
• 30 PPE Sutures inserted into aluminum pouches, sealed
in a self-seal 7”x13” paper plastic pouch
• 4 Hemostats sealed in Seal and Peel
• 12 Syringes (3 large, 3 medium and 6 small) sealed
in a self-seal 7”x13” paper plastic pouch
• 10 Glass Vials (amber with rubber stopper) sealed
in a self-seal 7”x13” paper plastic pouch
• 5 AN71 (4.5ml) Anprolene Ampoules
• 1 Humidichip placed in a Humiditube
• 1 Dosimeter
Environmental Conditions
All nine cycles performed under protocol AN74IOE were
conducted in two independent laboratories measuring 1898 ft³
and 5054 ft³. The studies were staggered and performed on three
different days. The 100-foot exhaust hose (0.5-inch diameter) was
coiled and vented directly to the outside. The ambient room
1 Andersen Scientific Protocol No.: AN74IOE, Title: AN74i STEL
15-Minute Operator Exposure Study.
temperatures of both laboratories ranged between 18 and
22°C with 45-65% relative humidity. All vents and recirculatory
fans were blocked and/or shut off, thereby
creating a static environment without air circulation or
exchange (a worst-case operator exposure scenario).
The operator wore a 15-minute STEL AirScan® badge and
the collection tube connected to the gas sampling pump on
their laboratory coat lapel (<6 inches from the breathing
zone). The operator followed his/her routine daily
procedures while performing these tests.
Sterilization and Unloading
Each AN74i sterilization cycle was performed using in
excess of 21.0g of Ethylene Oxide, in order to create a
worst-case operator exposure scenario. The cycles were
loaded with the “standard load,” and initiated at the end of
the working day. Fourteen hours later, at the cycle’s
conclusion, the sterilizers were opened, and the sterilization
bags were disconnected from the spool and transferred to
the post-sterilization quarantine holding area. Items were
carefully removed one at a time and placed on a metal
aeration cart. Dosimeter readings were performed at this
The gas-sampling bags were appropriately labeled and
immediately sent to Andersen Products Laboratory for
quantitative analysis. The AirScan® badges were
immediately developed following package instructions.
Average 15-Minute STEL EO Levels in ppm
Detection device Allowable limit Detected level
AirScan® <5.0 0
Sniffer™ <5.0 0.11
The results derived from this testing procedure (AN74IOE)
indicate that the AN74i operator was not exposed to
Ethylene Oxide levels above the OSHA STEL limits when
the unit was operated as recommended by the manufacturer.

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