🌿 Tetrahydrofuran in workplace air — gas chromatography with flame ionisation detection (GC-FID); lowest determinable concentration according to the standard 15 mg/m³, MAC (NDS) 150 mg/m³, STEL (NDSCh) 300 mg/m³, "skin" notation; PN-Z-04481:2017-10

Environment PN-Z-04481

Overview

WHAT THE STANDARD COVERS. Scope from the PKN card, in full: "This standard gives a method for determining tetrahydrofuran (CAS no.: 109-99-9) in workplace air using gas chromatography with flame ionisation detection. The method is used in the inspection of sanitary and hygienic conditions. The lowest tetrahydrofuran concentration that can be determined under the air sampling and determination conditions described in the standard is 15 mg/m3" (our translation; no full stop at the end on the card). The card gives neither the sorbent nor the solvent. We did not have the text of the standard (8 pages). The CIOP index of methods from 2000–2017 lists "Tetrahydrofuran – no. 4(86) 2015"; 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 516: "Tetrahydrofuran [109-99-9]" — NDS 150 mg/m³, NDSCh 300 mg/m³, "skin" notation (according to footnote 4 of the list, absorption through the skin "may be as important as in exposure by inhalation"). The lowest determinable concentration according to the card, 15 mg/m³, is 10 % of the NDS.

STATUS (card as of 04.10.2026). The card of PN-Z-04481:2017-10 (Polish version) has neither the heading "Withdrawn" nor a "Withdrawal date" line: published 09-10-2017, 8 pages, price group D, Health, Environment and Medicine Sector, KT 159 Chemical and Dust Hazards in the Working Environment, ICS 13.040.30; the card has no "Replaces" field. The PKN search for "PN-Z-04481" and "tetrahydrofuranu" (04.10.2026) returns only this standard.

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 04481 appears in 5 records at 5 laboratories; in the current PCA documents (read on 03.10.2026; issues from 11.06.2026 to 17.09.2026) — in 5 rows at the same laboratories; a search of all PCA documents downloaded from the BIP found no laboratories outside the database copy; no document repeats pages. The item of AB 1226 (issue no. 26 of 17.09.2026) is printed in bold italics — accreditation suspended at the body's request from 10.06.2026 to 07.12.2026; in the database copy the object has an asterisk next to it. Form "PN-Z-04481:2017-10" — AB 632, AB 1226, AB 300 (together with instruction IN-59 issue 3 of 18.12.2025) and AB 882 (together with procedure PB-01 issue 5 of 12.01.2026); AB 1207 — "PN-Z-04481:2017" (without the month), together with procedure PB-06A issue 7 of 20.01.2025. The "Laboratories" tab (query "PN-Z-04481") shows all 5 laboratories — checked with a tab query on the production server labcoda.pl on 04.10.2026.

WHAT THE LABORATORIES TEST (database copy). Object: working environment — air, at some laboratories samples collected on sorbent tubes (at AB 1207 — activated carbon); at AB 1207 the object recorded in the copy covers, besides the working environment, also samples of ambient and indoor air. Quantity: concentration (content) of tetrahydrofuran. Ranges in mg/m³: 0.17–1700 (AB 1207, GC-MS), 1.94–1400 (AB 300), 9.9–1654 (AB 882), 15–600 (AB 632), 15–300 (AB 1226, suspended). Technique: GC-FID — 4 laboratories; AB 1207 — gas chromatography with mass spectrometric detection (GC-MS).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — limit of quantification: according to the card 15 mg/m³; AB 632 and AB 1226 give this bottom limit, while AB 1207 (0.17), AB 300 (1.94) and AB 882 (9.9) give a lower one, which requires conditions different from those in the standard — the report should name them. Second — detector: the title and the card speak of GC-FID, while AB 1207 uses GC-MS according to an in-house procedure, with the standard alongside. Third — suspension: the AB 1226 item is suspended until 07.12.2026. Fourth — skin: the NDS has a "skin" notation, and a measurement in air does not cover absorption through the skin. Fifth — the NDSCh of 300 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, and the card gives neither the sorbent nor the solvent — we do not give the volume or flow rate of air sampling, the sorbent, the desorption solvent, the column, chromatograph conditions or calculations.

Method principle

Tetrahydrofuran in workplace air is determined by gas chromatography with flame ionisation detection (PKN card); the result in mg/m³ is compared with the NDS of 150 mg/m³ and the NDSCh of 300 mg/m³. The lowest determinable concentration according to the card is 15 mg/m³. WE DO NOT GIVE details — we did not have the text of the standard, and the card gives neither the sorbent nor the solvent.

Applications

• Workplace air — tetrahydrofuran — in the current scopes of 5 laboratories (one item suspended)
• Assessment of occupational exposure against the NDS of 150 mg/m³ and the NDSCh of 300 mg/m³, "skin" notation (Journal of Laws 2026 item 447, item 516 of the list)

Key parameters

Standard

Standard number

PN-Z-04481:2017-10

Title (PL)

Ochrona czystości powietrza — Oznaczanie tetrahydrofuranu na stanowiskach pracy metodą chromatografii gazowej z detekcją płomieniowo-jonizacyjną

Title (EN)

Air purity protection — Determination of tetrahydrofuran at workplaces by gas chromatography with flame ionisation detection

Step-by-step procedure

1. Sampling

   WE DO NOT GIVE the method — the card does not give the sorbent; in the scopes — sorbent tubes.

2. Sample preparation

   WE DO NOT GIVE the solvent or desorption conditions.

3. Analysis

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

4. Result and assessment

   Concentration in mg/m³; comparison with the NDS of 150 mg/m³ and the NDSCh of 300 mg/m³ (Journal of Laws 2026 item 447); lowest determinable concentration 15 mg/m³.

Required equipment and apparatus

Health and safety (OHS)

• Tetrahydrofuran — flammable, "skin" notation in the NDS list; chemical laboratory safety rules
• TECHNICAL NOTE: a bottom limit below 15 mg/m³ requires conditions different from those in the standard; the AB 1226 item is suspended until 07.12.2026

Frequently asked questions