Reference Source

Ethylene oxide

For Ethylene oxide, cfr section is 1910.1047; action level is 0.5 ppm calculated as an eight (8)-hour time-weighted average; pel is one (1) part EtO per million parts of air (1 ppm) as an 8-hour time-weighted average (8-hour TWA); surveillance trigger is 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; exam frequency is At least annually each employee exposed at or above the action level for at least 30 days in the past year, verified against its source on 2026-09-17.

Substance
Ethylene oxide
CFR section
1910.1047
Action level
0.5 ppm calculated as an eight (8)-hour time-weighted average verified
PEL
one (1) part EtO per million parts of air (1 ppm) as an 8-hour time-weighted average (8-hour TWA) verified
Surveillance trigger
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 verified
Exam frequency
At least annually each employee exposed at or above the action level for at least 30 days in the past year verified
Record retention
The employer shall ensure that this record is maintained for the duration of employment plus thirty (30) years verified
Sourcelaw.cornell.edu
Verified
Review by
DatasetOSHA medical surveillance trigger thresholds by substance

What the source says

Medical Surveillance —(1) General—(i) Employees covered. (A) The employer shall institute a medical surveillance program 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.

— law.cornell.edu, retrieved 2026-08-12

Where each value comes from

This source states these in separate places, so each value is shown with the passage that states it.

Action level

(b) Definitions: For the purpose of this section, the following definitions shall apply: Action level means a concentration of airborne EtO of 0.5 ppm calculated as an eight (8)-hour time-weighted average.

PEL

Ethylene oxide or EtO means the three-membered ring organic compound with chemical formula C2 H4 O. (c) Permissible exposure limits —(1) 8-hour time weighted average (TWA). The employer shall ensure that no employee is exposed to an airborne concentration of EtO in excess of one (1) part EtO per million parts of air (1 ppm) as an 8-hour time-weighted average (8-hour TWA).

Exam frequency

(2) Medical examinations and consultations—(i) Frequency. The employer shall make available medical examinations and consultations to each employee covered under paragraph (i)(1)(i) of this section on the following schedules: (A) Prior to assignment of the employee to an area where exposure may be at or above the action level for at least 30 days a year. (B) At least annually each employee exposed at or above the action level for at least 30 days in the past year.

Record retention

(ii) The record shall include at least the following information: (A) The name of the employee; (B) Physicians' written opinions; (C) Any employee medical complaints related to exposure to EtO; and (D) A copy of the information provided to the physician as required by paragraph (i)(3) of this section. (iii) The employer shall ensure that this record is maintained for the duration of employment plus thirty (30) years, in accordance with 29 CFR 1910.1020 .

— all from law.cornell.edu, retrieved 2026-08-12

Source

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