Page:NIOSH Manual of Analytical Methods - 3702.pdf/1

 ETHYLENE OXIDE by Portable GC

C2H4O

MW: 44.05

METHOD: 3702, Issue 2

CAS: 75-21-8

EVALUATION: FULL

OSHA : 1 ppm NIOSH: 0.1 ppm; C 5 ppm/10 min; carcinogen; Group I Pesticide ACGIH: 1 ppm; suspect carcinogen 1 ppm = 1.801 mg/m 3 @ NTP

PROPERTIES:

3702

RTECS: KX2450000

Issue 1: 15 August 1987 Issue 2: 15 August 1994

gas; d (liq.) 0.8694 g/mL @ 20 °C; BP 10.7 °C; MP -111 °C; explosive limits 3 to 100% (v/v) in air

SYNONYMS: 1,2-epoxyethane; oxirane

SAMPLING SAMPLER:

AMBIENT AIR OR BAG SAMPLE

FLOW RATE:

≥ 0.02 L/min; spot samples possible (See

MEASUREMENT TECHNIQUE:

GAS CHROMATOGRAPHY (PORTABLE), PHOTOIONIZATION DETECTOR

ANALYTE:

ethylene oxide

COLUMN:

1.2 m x 3 mm OD PTFE, packed with Carbopak BHT 40/100 mesh

CARRIER GAS:

ultrapure air, 15 mL/min

CALIBRATION:

bag standards or calibrated gas mixtures

RANGE:

0.001 to 1000 ppm

Step 1) SHIPMENT:

SAMPLE STABILITY: FIELD BLANKS:

calibration and carrier gas shipment must comply with hazardous materials shipment regulations

bag samples stable 24 h @ 25 °C [1] clean air, either in bag or from non-work area

ESTIMATED LOD: 2.5 pg per injection @ .001 ppm (1-mL injection) ACCURACY RANGE STUDIED:

0.1 to 700 ppm [1]

BIAS:

not significant

PRECISION (Sr):

<0.07 @ 0.05 to 0.2 ppm [1]

ˆ ): <0.09 [1] OVERALL PRECISION (S rT ACCURACY:

± 17%

APPLICABILITY: The working range is 0.001 to 1000 ppm in relatively non-complex atmospheres (e.g., sterilization facilities).

INTERFERENCES: Freon 12, carbon dioxide, and alcohols do not interfere. Other compounds with similar retention times under the same chromatographic conditions are potential interferences.

OTHER METHODS: This method complements Method 1614 [2] which utilizes solid sorbent collection, derivatization, and gas chromatographic measurement for ethylene oxide.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94