🌿 n-Butane (liquefied petroleum gas component) in workplace air — gas chromatography with flame ionisation detection (GC-FID), samples collected into absorption tubes; lowest determinable concentration according to the standard 190 mg/m³, MAC (NDS) 1900 mg/m³, STEL (NDSCh) 3000 mg/m³; PN-Z-04252-1:2012

Environment PN-Z-04252-1

Overview

WHAT THE STANDARD COVERS. Scope from the PKN card, in full: "This standard gives a method for determining the content of n-butane (CAS no.: 106-97-8) in workplace air using gas chromatography with flame ionisation detection. The method is used in the inspection of sanitary and hygienic conditions. The lowest concentration of n-butane that can be determined under the air sampling and determination conditions described in the standard is 190 mg/m3" (our translation; on the card without a full stop at the end). From the title: samples are collected "into absorption tubes"; the card gives neither the sorbent nor the air volume. We did not have the text of the standard (6 pages). The CIOP index of methods from 2000–2017 lists "n-Butan – nr 1(63) 2010"; we did not read the article and give nothing from it.

NDS VALUES (list in the annex to the regulation of 26 March 2026, Journal of Laws 2026 item 447). Item 69: "Butane [106-97-8]" — NDS 1900 mg/m³, NDSCh 3000 mg/m³, no "skin" notation. The lowest determinable concentration according to the card, 190 mg/m³, is 10 % of the NDS.

STATUS (cards as of 04.10.2026). The card of PN-Z-04252-1:2012 (Polish version) does not have the heading "Withdrawn": published 28-09-2012, 6 pages, price group C, Health, Environment and Medicine Sector, KT 159 Chemical and Dust Hazards in the Working Environment, ICS 13.040.30, "Replaces PN-Z-04252-1:1997". The card of the predecessor PN-Z-04252-1:1997 ("… Determination of propane and n-butane at workplaces by gas chromatography") has the heading "Withdrawn and replaced by PN-Z-04252-1:2012": published 19-12-1997, withdrawal date 28-09-2012, 4 pages; its scope in full: "A method is given consisting in isolated sampling of the tested air into a gas pipette and determination of the concentration of propane and n-butane by gas chromatography with flame ionisation detection. The lowest concentrations of liquefied petroleum gas components that can be determined by this method are 290 mg/m3 for propane and 380 mg/m3 for n-butane. The method also allows quantitative determination of other liquefied petroleum gas components, e.g. ethane, propene, isobutene and isobutane" (our translation; spelling as on the card). The PKN search for "PN-Z-04252" (04.10.2026) shows three items: parts 1:2012 (n-butane) and 2:2012 (propane) without the label "Withdrawn" and the withdrawn part 1:1997. Propane is described in a separate entry of this database (PN-Z-04252-2:2012).

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data load up to 17.09.2026, read on 04.10.2026). The number 04252-1 appears in 6 records at 3 laboratories — all with the year 2012; in the current PCA documents (read on 03.10.2026; issues from 26.01.2026 to 02.07.2026) — in 4 rows at the same laboratories (at AB 875 the waste gas row covers three records of the copy: sampling, concentration and emission); a search of all PCA documents downloaded from the BIP found no laboratories outside the database copy; no item is suspended, and no document repeats pages. The 1997 edition is not cited by any laboratory. The form "PN-Z-04252-1:2012" — AB 632 and AB 849; AB 875 — next to Test Procedure PB 052 edition 2 of 02.05.2013. The "Laboratories" tab (search term "PN-Z-04252-1") shows all 3 laboratories — checked with a tab query on the labcoda.pl production server on 04.10.2026.

WHAT THE LABORATORIES TEST (database copy and PCA documents). Working environment — air, samples collected on sorbent tubes: AB 632 — n-butane, 190–6000 mg/m³ (0.57–18.0 mg per sample); AB 849 — butane, 190–4800 mg/m³ (0.57–14.4 mg per sample); AB 875 — butane, 20.0–6000 mg/m³ (0.060–4.50 mg per sample). AB 875 also applies the standard to waste gases (general environment, samples collected on sorbent tubes): sampling by the aspiration method, butane concentration 20.0–6000 mg/m³ and butane emission by calculation. Technique: gas chromatography with flame ionisation detection (GC-FID) — all 3 laboratories.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — limit of quantification: according to the card 190 mg/m³; AB 632 and AB 849 give this limit, while AB 875 gives 20.0 mg/m³, which requires conditions different from those in the standard (AB 875 uses its own procedure PB 052) — the report should name them. Second — "butane" versus "n-butane": the standard and AB 632 speak of n-butane, the NDS list and two laboratories of butane; the result concerns n-butane; the card of the withdrawn 1997 edition mentioned the possibility of determining other liquefied petroleum gas components (ethane, propene, isobutene, isobutane), the card of the 2012 edition does not mention them. Third — object: at AB 875 the same standard serves for waste gases, i.e. an emission measurement, for which the NDS is not a reference value. Fourth — the NDSCh of 3000 mg/m³ requires a short-term measurement whose conditions WE DO NOT GIVE.

WHAT WE DO NOT GIVE. We did not have the text of the standard — we do not give the sorbent in the tubes, the volume or flow rate of air sampling, the way n-butane is released from the tube, the column, the chromatograph conditions or calculations; we do not describe how the 2012 method differs from the 1997 method beyond what the cards say.

Method principle

n-Butane from workplace air is collected into absorption tubes (title of the standard) and determined by gas chromatography with flame ionisation detection (PKN card); the result in mg/m³ is compared with the NDS of 1900 mg/m³ and the NDSCh of 3000 mg/m³. Lowest determinable concentration according to the card — 190 mg/m³. WE DO NOT GIVE details — we did not have the text of the standard.

Applications

• Workplace air — n-butane (liquefied petroleum gas component) — in the current scopes of 3 laboratories; at AB 875 also waste gases
• Assessment of occupational exposure against the NDS of 1900 mg/m³ and the NDSCh of 3000 mg/m³ (Journal of Laws 2026 item 447, item 69 of the list)

Key parameters

Standard

Standard number

PN-Z-04252-1:2012

Title (PL)

Ochrona czystości powietrza — Badania zawartości składników gazu płynnego — Część 1: Oznaczanie n-butanu na stanowiskach pracy metodą chromatografii gazowej z pobieraniem próbek do rurek pochłaniających

Title (EN)

Air purity protection — Tests for liquefied petroleum gas components — Part 1: Determination of n-butane at workplaces by gas chromatography with sampling into absorption tubes

Step-by-step procedure

1. Sampling

   Air into absorption tubes (title of the standard); WE DO NOT GIVE the sorbent, volume or flow rate.

2. Sample preparation

   WE DO NOT GIVE the way n-butane is transferred from the tube to the analysis — the card does not describe it.

3. Analysis

   Gas chromatography with flame ionisation detection (PKN card); WE DO NOT GIVE the conditions.

4. Result and assessment

   Concentration in mg/m³; comparison with the NDS of 1900 mg/m³ and the NDSCh of 3000 mg/m³ (Journal of Laws 2026 item 447); lowest determinable concentration 190 mg/m³.

Required equipment and apparatus

Health and safety (OHS)

• n-Butane — chemical laboratory safety rules
• TECHNICAL NOTE: a bottom limit below 190 mg/m³ requires conditions different from those in the standard; the 2012 standard determines only n-butane

Frequently asked questions