🌿 Cyclohexane in workplace air — adsorption of the vapours on activated carbon, extraction with toluene, gas chromatography; standard withdrawn in 2011, NDS 300 mg/m³, PN-Z-04151-02

Environment PN-86/Z-04151/02

Overview

WHAT THE STANDARD COVERS. Scope from the PKN card, in full (our translation): "A method has been established consisting in the adsorption of cyclohexane vapours on activated carbon, its extraction with toluene and chromatographic analysis of the resulting solution. The method is used to determine the concentration of cyclohexane vapours in workplace air. The apparatus and instruments, the preparation of reagents and solutions, the operating conditions of the chromatograph and the preparation of the calibration curve are given" (without a full stop at the end on the card). The card does not give the detector, the air volume and flow, the amount of carbon, the column or the lowest determinable concentration. We did not have the text of the standard (3 pages).

LIMIT VALUES. According to the regulation of the Minister of Family, Labour and Social Policy of 26 March 2026 (Journal of Laws 2026, item 447, annex, item 128), for cyclohexane [110-82-7] the NDS is 300 mg/m³ and the NDSCh 1000 mg/m³; the list gives the "skin" notation for it.

STATUS (state of the cards on 30 September 2026). The card of PN-Z-04151-02:1986 (Polish version) has the header "Withdrawn": published 16-01-1986, "Withdrawal date: 17-10-2011", 3 pages, price group B, Health, Environment and Medicine Sector, KT 159 for Chemical and Dust Hazards in the Working Environment, ICS 13.040.30; a national standard, without "Introduces" and "Replaced by" fields. The PKN search for "PN-Z-04151" (30 September 2026) shows three sheets of the series, all withdrawn: 01:1986 (general provisions and scope — withdrawal date 29-11-2007), 02:1986 and 10:1990 (cyclohexane vapours in rooms intended for permanent occupancy; according to the card — activated carbon, extraction with carbon disulfide, determinability 0.001 mg/m³; withdrawal date 30-11-2010). The PKN search for "cykloheksanu" (cyclohexane, 30 September 2026) shows six items, all withdrawn: three sheets of this series, two sheets of PN-Z-04137 (methylcyclohexane) and PN-C-04655:1964 (pesticides) — the catalogue shows no current standard with cyclohexane in its title.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation-scope database, data loaded up to 17 September 2026, read on 30 September 2026). All notations of number 04151-02: 13 records at 11 laboratories, i.e. 12 entries — the copy splits one entry of AB 886 into two records; in the current PCA documents the number appears 12 times. Notations: "PN-86/Z-04151/02" — 8 laboratories (AB 481, AB 581, AB 632, AB 647, AB 882, AB 886, AB 964, AB 1144), "PN-Z-04151-02:1986" — AB 340 and AB 882, "PN-86/Z-04151.02" — AB 622 and AB 746. A procedure alongside the standard — AB 882 (PB-01 issue 5 of 12.01.2026 with GC-FID and PB-10 issue 1 of 31.08.2022 with GC-MS) and AB 886 (PB-02 issue 12 of 16.10.2023). The "Laboratories" tab looks for notations that BEGIN with "PN-86/Z-04151/02" (the form used in the scopes, the most frequent one) and will show 8 of the 11 laboratories — checked with the tab's query on the production server labcoda.pl on 30 September 2026: 8; it will not show AB 340, AB 622 and AB 746, and the PKN catalogue form "PN-Z-04151-02" would give 2. Current scopes on the PCA website (read on 30 September 2026, issues from 26.11.2025 to 18.08.2026): all entries are in the issues in force, each of the 20 pairs of range figures from the copy appears in the current document and no entry is suspended.

MATRIX, TECHNIQUE AND RANGES. Workplace air — all 11 laboratories. Technique: GC-FID — 11 laboratories; GC-MS — the second entry of AB 882. Concentration ranges (10 laboratories; AB 886 gives only the mass in the sample, (0.005 – 30) mg): lower limits from 1.90 mg/m³ (AB 882), 2.75 mg/m³ (AB 581) and 3.3 mg/m³ (AB 481) to 19.5 mg/m³ (AB 964) and 30 mg/m³ (AB 632, AB 647); upper limits from 1000 mg/m³ (AB 1144) to 3000 mg/m³ (AB 882) and 4000 mg/m³ (AB 481). The card gives no determinability, so the lower limits of the ranges rest on the laboratories' validation.

ALONGSIDE THIS STANDARD. Cyclohexane in workplace air without this standard is determined by 16 laboratories: according to the method from the quarterly "Podstawy i Metody Oceny Środowiska Pracy" 2011, no. 1 (67), pp. 35–44 — AB 522 (with procedure PB-17-27), AB 1207 (GC-MS, with PB-06A, (0.17 – 5300) mg/m³), AB 1642 ((0.050 – 1124) mg/m³) and AB 1854 (with work instruction IR-23); according to the method from the same quarterly of 2007, no. 1 (51), pp. 141–147 — AB 300 ((1.0 – 5000) mg/m³), AB 565 (in one entry together with benzene, toluene and other solvents) and AB 1226; according to in-house procedures — AB 484 (method no. 031), AB 647 (PB-14, in a separate entry next to the entry with this standard), AB 719 (PA-14), AB 802 (PB-06/09), AB 849 (PB-29, (0.571 – 5040) mg/m³), AB 869 (EKOLAB/LB/PB-08), AB 1065 (PB-06, GC-MS) and AB 1257 (PB-05); in a flexible scope — AB 934. The entries of AB 522 are SUSPENDED from 18.08.2026 to 14.02.2027, and the entry of AB 1226 from 10.06.2026 to 07.12.2026 (bold italics and a footnote in the current PCA documents, read on 30 September 2026); the other rows are not suspended. The lowest starting points are AB 1642 (0.050 mg/m³) and AB 1207 (0.17 mg/m³) — both according to the 2011 method.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — status: the standard has been withdrawn since 2011 and the card names no successor; the accreditation for it continues, but the report should give the document actually used for the test (two laboratories combine it with an in-house procedure). Second — the notation of the number: the same tests appear under three forms of the designation, so searching by one of them loses some of the laboratories (the tab shows 8 of 11). Third — the lower limit: the card gives no determinability, and the laboratories' ranges start from 1.90 to 30 mg/m³ — with an NDS of 300 mg/m³ all of them reach 1/10 of the NDS, but the limit comes from the laboratory's validation, not from the standard. Fourth — similar names: cyclohexane (NDS 300 mg/m³), methylcyclohexane (NDS 1600 mg/m³) and cyclohexene (NDS 300 mg/m³) have separate entries in the list and separate methods — what counts in the report is the full name and the CAS number [110-82-7]. Fifth — the "skin" notation: a measurement in air does not cover absorption through the skin.

WHAT WE DO NOT GIVE. We did not have the text of the standard — PKN sells it (3 pages). We do not give the air volume and flow, the amount of carbon, the volume of toluene, the detector, the column and operating conditions of the chromatograph, the calibration curve, the formula or the precision.

Method principle

According to the PKN card, cyclohexane vapours from workplace air are adsorbed on activated carbon, the cyclohexane is extracted with toluene and the resulting solution is analysed by gas chromatography against a calibration curve. We DO NOT GIVE the air volume, the chromatograph conditions or the determinability — we did not have the text of the standard, and the card does not give them.

Applications

• Cyclohexane in workplace air — in the scopes of 11 laboratories (NDS 300 mg/m³, NDSCh 1000 mg/m³, "skin" notation)

Key parameters

Standard

Standard number

PN-Z-04151-02:1986 (wersja polska; norma wycofana)

Title (PL)

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

Title (EN)

Air purity protection — Tests for cyclohexane content — Determination of cyclohexane at workplaces by gas chromatography with sample enrichment

Step-by-step procedure

1. Status of the document

   PKN card: PN-Z-04151-02:1986 withdrawn on 17-10-2011, no successor on the card (state of the card on 30 September 2026).

2. Sampling

   Adsorption of cyclohexane vapours on activated carbon; we DO NOT GIVE the air volume and flow.

3. Extraction

   With toluene (PKN card); we DO NOT GIVE the volume and time.

4. Analysis

   Gas chromatography of the solution, calibration curve; in the scopes — FID or MS.

5. Result

   Concentration in mg/m³ for comparison with the NDS of 300 mg/m³ and the NDSCh of 1000 mg/m³; we DO NOT GIVE the formula.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Toluene and cyclohexane are flammable; toluene is harmful — extraction and preparation of solutions under an efficient fume hood, away from ignition sources
• TECHNICAL NOTE: the standard has been withdrawn since 2011 — check in the report whether the laboratory tests according to it or according to an in-house procedure based on it

Frequently asked questions