🌿 4-Methylpentan-2-one (methyl isobutyl ketone) in workplace air — activated carbon, acetone, gas chromatography with sample enrichment; limit of quantification according to the standard 50 mg/m³; MAC (NDS) 83 mg/m³, STEL (NDSCh) 200 mg/m³; PN-Z-04165-02:1986 (withdrawn 17-10-2011)

Environment PN-Z-04165-02

Overview

WHAT THE STANDARD COVERS. Scope from the PKN card, in full: "The test method consists in adsorption of methyl isobutyl ketone vapour on activated carbon, extracting it with acetone and chromatographic analysis of the solution obtained. The limit of quantification of the method is 50 mg in 1 cubic metre of air" (our translation; no full stop at the end on the card). The card does not give the detector, the volume or the flow rate of the air sample. We did not have the text of the standard (3 pages). The CIOP method index lists the article "4-Metylopentan-2-on" in the quarterly "Podstawy i Metody Oceny Środowiska Pracy" No. 4(30) of 2001 — we have not read it.

NDS VALUES (list in the annex to the regulation of 26 March 2026, Journal of Laws 2026 item 447). Item 389: "4-Methylpentan-2-one [108-10-1]" — NDS 83 mg/m³, NDSCh 200 mg/m³, no "skin" notation and no note on the fraction; the substance is not covered by the transitional provisions of § 2. The limit of quantification according to the card of this standard, 50 mg/m³, is about 60 % of the NDS; according to the card of PN-Z-04372:2009 it is 8 mg/m³, i.e. about 10 % of the NDS.

STATUS (cards as of 05.10.2026). The card of PN-Z-04165-02:1986 (Polish version) has the heading "Withdrawn" without naming a replacing standard: publication 23-05-1986, withdrawal date 17-10-2011, 3 pages, price group B, Health, Environment and Medicine Sector, KT 159 Chemical and Dust Hazards in the Working Environment, ICS 13.040.30. The series is called "Tests for methyl butyl ketone content", while part -02 concerns methyl isobutyl ketone. The card of PN-Z-04372:2009 ("… Determination of 4-methylpentan-2-one at workplaces by gas chromatography") has neither the heading "Withdrawn" nor a "Replaces" field: publication 25-02-2009, 7 pages, activated carbon, desorption with a solution of methanol in carbon disulfide, limit of quantification 8 mg/m³; it is described in a separate entry of this database. PKN search (05.10.2026): under "PN-Z-04165" — 3 parts of the series: -01:1986 (general provisions) and -02:1986 labelled "Withdrawn", and the current -3:2001 (hexan-2-one); under "metyloizobutyloketonu" — only this standard; under "metylopentan-2-onu" — PN-Z-04372:2009 and PN-Z-04368:2008 (4-hydroxy-4-methylpentan-2-one); under "heksonu" — no results.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read on 05.10.2026). Number 04165-02 appears at 3 laboratories — in 4 records of the database copy, because the entry of AB 886 is split into 2 records in the copy; in the current PCA documents (read on 03.10.2026; issues from 12.02.2026 to 18.08.2026) — in 3 rows at the same laboratories; a search of all PCA documents downloaded from the BIP found no laboratories outside the database copy; no entry is suspended and no pages are repeated in any document. Notations: "PN-Z-04165-02:1986" — AB 340; "PN-86/Z-04165.02" — AB 746; "PN-86/Z-04165/02" — AB 886, alongside procedure PB-02 issue No. 12 of 16.10.2023. The "Laboratories" tab searches for records beginning with the term entered: "PN-Z-04165-02", "PN-86/Z-04165.02" and "PN-86/Z-04165/02" show 1 laboratory each, 3 in total — the same in the copy and on the labcoda.pl production server (tab queries on 05.10.2026). None of these 3 laboratories cites PN-Z-04372:2009, which according to the database copy is in the scopes of 11 other laboratories.

WHAT THE LABORATORIES TEST (database copy and PCA documents). Subject: working environment — air; AB 746 — samples collected into sorbent tubes, AB 886 — on sorption tubes. Quantity: concentration (content) of 4-methylpentan-2-one; AB 746 adds "(methyl isobutyl ketone, hexone)". Ranges: AB 886 — 0.17–1000 mg/m³ (0.005–30 mg per sample); AB 746 — 0.62–400 mg/m³ (0.010–5.0 mg per sample); AB 340 — 0.90–1440 mg/m³. Technique: gas chromatography with flame ionisation detection (GC-FID) — all three.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — withdrawn standard: this standard has not been valid since 17-10-2011, and the current PN-Z-04372:2009 describes a different desorption (a solution of methanol in carbon disulfide instead of acetone); the report should state explicitly that the standard is withdrawn. Second — lower limit: the card gives a limit of quantification of 50 mg/m³, i.e. about 60 % of the NDS, while all three laboratories start below 1 mg/m³, which requires conditions different from those on the card — the report should name them. Third — names: the series is called "methyl butyl ketone", and its current part -3:2001 concerns hexan-2-one, a different substance with a different NDS item; methyl isobutyl ketone is 4-methylpentan-2-one [108-10-1]. Fourth — similar name: PN-Z-04368:2008 concerns 4-hydroxy-4-methylpentan-2-one, not this substance. Fifth — searching: the number appears in three notations and no single search term shows all 3 laboratories.

WHAT WE DO NOT GIVE. We did not have the text of the standard — we do not give the detector according to the standard, the volume or flow rate of the air sample, the amount of carbon, the volume of acetone, the column, the chromatograph conditions or the calculations. We do not claim that PN-Z-04372:2009 replaced this standard — the cards do not say so. We do not give the content of the CIOP article of 2001 — we have not read it.

Method principle

Methyl isobutyl ketone (4-methylpentan-2-one) vapour from workplace air is adsorbed on activated carbon, extracted with acetone and the solution obtained is analysed chromatographically (PKN card); limit of quantification according to the card — 50 mg/m³. The result in mg/m³ is compared with the NDS of 83 mg/m³ and the NDSCh of 200 mg/m³ (Journal of Laws 2026 item 447). The standard has been withdrawn since 17-10-2011; the current standard for this substance is PN-Z-04372:2009.

Applications

• Workplace air — 4-methylpentan-2-one — in the current scopes of 3 laboratories despite the withdrawal of the standard (the current PN-Z-04372:2009 — at 11 others)
• Assessment of occupational exposure against the NDS of 83 mg/m³ and the NDSCh of 200 mg/m³ (Journal of Laws 2026 item 447, item 389 of the list)

Key parameters

Standard

Standard number

PN-Z-04165-02:1986

Title (PL)

Ochrona czystości powietrza — Badania zawartości metylobutyloketonu — Oznaczanie metyloizobutyloketonu na stanowiskach pracy metodą chromatografii gazowej z wzbogacaniem próbki

Title (EN)

Air purity protection — Tests for methyl butyl ketone content — Determination of methyl isobutyl ketone at workplaces by gas chromatography with sample enrichment

Step-by-step procedure

1. Sampling

   Adsorption of methyl isobutyl ketone vapour on activated carbon (PKN card); WE DO NOT GIVE the volume and flow rate.

2. Extraction

   Extraction with acetone (PKN card); WE DO NOT GIVE the volume and time.

3. Analysis

   Chromatographic analysis of the solution obtained (PKN card); in the scopes — GC-FID; WE DO NOT GIVE the conditions.

4. Result and assessment

   Concentration of 4-methylpentan-2-one in mg/m³; comparison with the NDS of 83 mg/m³ and the NDSCh of 200 mg/m³ (Journal of Laws 2026 item 447).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• 4-Methylpentan-2-one and acetone — safety rules of the chemical laboratory
• TECHNICAL NOTE: standard withdrawn since 17-10-2011 — the current standard is PN-Z-04372:2009; the limit of quantification on the card (50 mg/m³) is about 60 % of the NDS and higher than the lower limits of all three laboratories

Frequently asked questions