Ethyl acetate OSHA PEL checker.

The ethyl acetate row in Table Z-1

The OSHA limit for ethyl acetate is 400 ppm over an 8-hour shift. The row below is copied from Table Z-1, Limits for Air Contaminants, in 29 CFR 1910.1000 as published in the eCFR, with values exactly as printed.

Reading the footnotes

The column headings carry footnote markers, which change how the numbers should be read. The eCFR prints them as follows.

• 1: The PELs are 8-hour TWAs unless otherwise noted; a (C) designation denotes a ceiling limit. They are to be determined from breathing-zone air samples.
• (a): Parts of vapor or gas per million parts of contaminated air by volume at 25 °C and 760 torr.
• (b): Milligrams of substance per cubic meter of air. When entry is in this column only, the value is exact; when listed with a ppm entry, it is approximate.
• (c): The CAS number is for information only. Enforcement is based on the substance name. For an entry covering more than one metal compound, measured as the metal, the CAS number for the metal is given—not CAS numbers for the individual compounds.

For ethyl acetate, that means three things. The 400 ppm figure is by volume, at 25 °C and 760 torr. The 1400 mg/m3 figure is only an approximate mass equivalent of it. And enforcement goes by the name in the first column, not the CAS number.

Why this entry is an 8-hour average

Neither number in the ethyl acetate row has a (C) in front of it, so footnote 1 makes it an 8-hour time weighted average (TWA). That is an average over the shift, not a cap on any single moment. Paragraph (a)(2) reads: “An employee's exposure to any substance in Table Z-1, the exposure limit of which is not preceded by a “C”, shall not exceed the 8-hour Time Weighted Average given for that substance in any 8-hour work shift of a 40-hour work week.”

Entries marked (C) are different. They are ceiling values under paragraph (a)(1), and exposure shall at no time exceed them.

Skin designation

The Skin designation column is blank for ethyl acetate in the eCFR table. Table Z-1 marks no skin-absorption designation on this row.

Worked example

These readings are invented, to show the paragraph (d)(1) arithmetic. One employee's shift has two hours at 600 ppm, two hours at 300 ppm and four hours at 200 ppm of ethyl acetate.

E = (2 × 600 + 2 × 300 + 4 × 200) ÷ 8 = 2,600 ÷ 8 = 325 ppm.

The 8-hour average is 325 ppm, below the printed 400 ppm, even though the 600 ppm hours were above it. That is how a TWA limit works. The result says nothing about whether 600 ppm for two hours is acceptable for a real task, and the page does not rule on that. The CFR works the same method in its own Substance A example for a 100 ppm limit, which comes to 81.25 ppm.

Computation formulae in paragraph (d)

Paragraph (d)(1)(i) gives the cumulative exposure formula for an 8-hour shift: E = (Ca Ta + Cb Tb + . . .Cn Tn) ÷ 8, where E is the equivalent exposure for the working shift, C is the concentration during any period of time T where the concentration remains constant, and T is the duration in hours of the exposure at the concentration C. The value of E shall not exceed the 8-hour time weighted average specified in subpart Z of 29 CFR part 1910 for the substance involved.

Paragraph (d)(2)(i) gives the formula for mixtures: In case of a mixture of air contaminants an employer shall compute the equivalent exposure as follows: Em = (C1 ÷ L1 + C2 ÷ L2) + . . .(Cn ÷ Ln), where C is the concentration of a particular contaminant and L is the exposure limit for that substance specified in subpart Z of 29 CFR part 1910. The value of Em shall not exceed unity (1). The paragraph introducing these formulae applies them to substances for which 8-hour time weighted averages are listed.

What paragraph (e) says about controls

This page does not recommend any exposure-control measure. Paragraph (e) is quoted here only for reference: “To achieve compliance with paragraphs (a) through (d) of this section, administrative or engineering controls must first be determined and implemented whenever feasible. When such controls are not feasible to achieve full compliance, protective equipment or any other protective measures shall be used to keep the exposure of employees to air contaminants within the limits prescribed in this section. Any equipment and/or technical measures used for this purpose must be approved for each particular use by a competent industrial hygienist or other technically qualified person. Whenever respirators are used, their use shall comply with 1910.134.”

Limits of this page

This page reads Table Z-1 and the paragraphs of 1910.1000 quoted above. It does not say that an exposure below a printed limit is safe. It does not cover Table Z-2 or Z-3 substances, other OSHA substance-specific standards, state-plan rules, or recommended limits from other bodies. It does not tell you how to sample, how to control exposure or which respirator to use.

The checker compares the one number you type with the printed figure. It applies the “shall not exceed” wording as written, so a reading equal to the limit is not above it. For a real workplace, ask a qualified industrial hygienist, read your safety data sheet and contact the OSHA office for your area. The eCFR lists the newest content version of this section as May 30, 2017.

Sources

Sources opened and read November 12, 2026.

• eCFR: 29 CFR 1910.1000, Air contaminants, Table Z-1 and paragraphs (a), (d) and (e) (text requested as of November 10, 2026; read November 12, 2026)
• eCFR versioner API: version history of 29 CFR 1910.1000 (read November 12, 2026)