Metodo Ohsa 103 Gases Anestesicos

ENFLURANE
HALOTHANE
ISOFLURANE
Method number:

103

Matrix:

Air

Target concentration, TC:

enflurane
TC

halothane

isoflurane

low

mg/m

3

low

high

low

high

1

ppm

high
75

1

50

1

75

7.5

566

8

403

7.5

566

OSHA PEL:
ACGIH TLV:

None
75 ppm (566 mg/m3) for enflurane
50 ppm (403 mg/m3) for halothane

Procedure:Samples are collected by drawing a known volume of air through
standard size (6-mm o.d., 150/75 mg) Anasorb CMS or (6 -mm o.d.,
140/70 mg) Anasorb 747 tubes. Samples are desorbed with CS2 and
analyzed by GC using a flame-ionization detector (FID).

Air volume
and sampling rate:

12 L at 0.05 L/min

Reliable quantitation limit:

enflurane

halothane

isoflurane

Anasorb

CMS747

CMS

747

CMS

747

ppb

25.0

40.7

24.4

21.3

23.0

23.5

µg/m3

189

307

197

172

174

177

Standard error of estimate
at the target concentration:

enflurane

halothane

isoflurane

Anasorb

CMS

747

CMS

747

CMS

747

low TC

0.072

0.058

0.076

0.054

0.078

0.059

high TC

0.083

0.077

0.0700.058

0.085

0.061

Special requirements:

Samples collected on Anasorb CMS for halothane should be stored at
reduced temperature following receipt at the laboratory until analysis.

Status of method:

Evaluated method. This method has been subjected to the established
evaluation procedures of the Organic Methods Evaluation Branch.

Date: May 1994

Chemist: Donald BurrightOrganic Methods Evaluation Branch
OSHA Salt Lake Technical Center
Salt Lake City, UT 84165-0200

1. General Discussion
1.1 Background
1.1.1 History
The objective of this method is to eliminate the need to use two adsorbent tubes connected in series as
specified for enflurane and halothane in OSHA Method 29 (Ref. 5.1), and to expand the methodology to
include the newer anesthetic gases,isoflurane and desflurane. (Desflurane will appear as a separate
method because it requires different analytical conditions.) Enflurane, halothane and isoflurane wer e each
evaluated at two target concentrations because NIOSH recommended exposure limits (Refs. 5.2 and 5.3)
are considerably lower than the current ACGIH TLVs (Ref. 5.4). For this reason, the method was
evaluated at a lower targetconcentration of 1 ppm for all three analyses. Currently there are no OSHA
PELs for these substances. Preliminary studies were performed with the following adsorbents: Anasorb
CMS, Anasorb 747, Carbosieve S-III and activated coconut charcoal. Anasorb CMS and Anasorb 747 were
both good candidates for an improved sampler as neither adsorbent required two tube in series.
Evaluation tests were begunwith both adsorbents in the anticipation that one would dearly surpass the
other in performance. Since this did not occur, both were evaluated and are presented as sampling
options.
ACGIH has recommended a TLV-TWA of 75 ppm for enflurane and 50 ppm for halothane (Ref. 5.4). The
TLV for enflurane is based on the assumption enflurane is a safer anesthetic gas than halothane. The TLV
forhalothane is based on a comparison of toxicity and TLVs of trichloroethylene and chloroform. (Ref.
5.4) The ACGIH recommendations are the basis for setting the higher target concentrations of enflurane
and halothane for the evaluation of this method. A higher target concentration of 75 ppm was set for
isoflurane because it is a geometric isomer of enflurane. NIOSH has recommended that exposure to thesehalogenated anesthetic gases should be controlled with a 60-min ceiling value of 2 ppm (Ref. 5.2). The
anesthetic gases are usually administered in conjunction with nitrous oxide.
1.1.2 Toxic effects (This section is for information only and should not be taken as the basis of OSHA
policy.)
Current scientific evidence obtained from human and animal studies sugges t that chronic exposure to...