🌿 Dichloromethane in workplace air — adsorption of vapours on activated or modified charcoal, desorption with carbon disulphide, gas chromatography; lowest determinable concentration according to the standard 8.8 mg/m³, MAC (NDS) 88 mg/m³, STEL (NDSCh) 353 mg/m³, "skin" notation; PN-Z-04437:2011

Environment PN-Z-04437

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card, in full (our translation): "A method is given consisting in adsorption of dichloromethane vapours on activated or modified charcoal, desorption of the compound with carbon disulphide and analysis of the solution obtained by gas chromatography. The lowest concentration of dichloromethane that can be determined by this method is 8.8 mg/m3" (no full stop at the end on the card). We did not have the text of the standard (6 pages).

ACCORDING TO THE CIOP PROCEDURE (A. Woźnica, "Dichloromethane – determination method", Podstawy i Metody Oceny Środowiska Pracy 2009, no. 1(59), pp. 135–140 — read in full). This procedure was published two years before the standard, with the same limit of quantification of 8.8 mg/m³; we do not claim that the standard repeats it — the card speaks of "activated or modified" charcoal, the procedure only of activated charcoal. In the procedure: tubes with two layers of activated charcoal (200 and 50 mg), up to 6 l of air at a flow rate not exceeding 1 l/h, samples stable for 6 days in a freezer; desorption with 1 ml of carbon disulphide for 30 min; GC-FID, for example a capillary column with polyethylene glycol 2-nitroterephthalate 50 m × 0.32 mm, film 0.5 µm, helium 2 ml/min, column temperature from 55 °C to 100 °C (5 °C/min); the amount in the shorter layer should not exceed 10 % of the amount in the longer one, otherwise the result is indicative; the desorption efficiency is determined for each new batch of sorbent. Validation data: range 0.0528–1.056 mg/ml (8.8–176 mg/m³ for 6 l of air), limit of detection 12.9 ng/ml, limit of quantification 42.9 ng/ml, correlation coefficient 0.9999, total precision 7.23 %, method uncertainty 32.94 %. In clause 11 the procedure refers to "clause 5.7", which does not exist in the text — the solution for determining the desorption efficiency is clause 5.5. The NDS quoted in the procedure (88 mg/m³) comes from the 2007 regulation.

NDS VALUES (list in the annex to the regulation of 26 March 2026, Journal of Laws 2026 item 447). Item 165: "Dichloromethane [75-09-2]" — NDS 88 mg/m³ (25 ppm), NDSCh 353 mg/m³ (100 ppm), "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, 8.8 mg/m³, is 10 % of the NDS.

STATUS (card as of 04.10.2026). The card of PN-Z-04437:2011 (Polish version) has no "Withdrawn" heading and no "Withdrawal date" row: published 12-09-2011, 6 pages, price group C, 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-04437" (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 04437 appears in 6 records at 6 laboratories; in the current PCA documents (read on 03.10.2026; issues from 12.02.2026 to 17.09.2026) — in 6 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. SUSPENSION: at AB 1226 (issue no. 26 of 17.09.2026) the item with PN-Z-04437:2011 is set in bold italics — "Accreditation suspended at the request of the body in the part of the scope marked in bold italics from 10.06.2026 to 07.12.2026" (our translation); in the database copy the trace is an asterisk at the object. All entries have the form "PN-Z-04437:2011"; AB 719 — "PN-Z-04437:2011 pkt 6" (clause 6) next to procedure PA-31 edition 7 of 24.01.2025. The "Laboratories" tab (query "PN-Z-04437") shows all 6 laboratories, including AB 1226 — checked with the tab's query on the production server labcoda.pl on 04.10.2026.

WHAT THE LABORATORIES TEST (database copy). Object: working environment — air; at AB 632 and AB 886 samples collected on sorbent or sorption tubes, at AB 719 — on sorption tubes with activated charcoal, at AB 869 — "working environment" without addition. Quantity: concentration (content) of dichloromethane. Ranges in mg/m³: 0.18–1000 (AB 886, also 0.05–283 ppm), 5.92–621.00 (AB 340, also 1.67–176.2 ppm), 8.8–706 (AB 632, also 2.49–200 ppm), 8.8–176 (AB 1226 — suspended item; together with 0.0528–1.056 mg per sample these are the same figures as the measuring range of the CIOP procedure — in the procedure 0.0528–1.056 mg/ml with 1 ml of desorbent and 8.8–176 mg/m³ for 6 l of air); per sample: 0.01–5 mg (AB 869), 0.020–19.0 mg (AB 719). Technique: gas chromatography with flame ionisation detection (GC-FID) — all 6 laboratories.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — suspension: AB 1226 has the item suspended from 10.06.2026 to 07.12.2026, while the tab and the database copy show it — during this period that laboratory's result for dichloromethane is not an accredited result. Second — limit of quantification: according to the card the lowest concentration determinable by this method is 8.8 mg/m³; AB 886 (0.18 mg/m³) and AB 340 (5.92 mg/m³) state a lower bottom limit, which requires conditions different from those in the standard — the report should name them. Third — sorbent: the card allows activated "or modified" charcoal; which sorbent was used should follow from the report. Fourth — skin and NDSCh: measurement in air does not cover absorption through the skin; WE DO NOT GIVE measurement conditions against the NDSCh of 353 mg/m³. Fifth — the figures from the CIOP procedure describe the 2009 procedure; we do not attribute them to the standard.

WHAT WE DO NOT GIVE. We did not have the text of the standard — we do not give the volume or flow rate of air sampling, the kind of modified charcoal, the column, chromatograph conditions, desorption efficiency or calculations according to the standard; data from the CIOP procedure are given as data of the procedure.

Method principle

Dichloromethane vapours from workplace air are adsorbed on activated or modified charcoal, desorbed with carbon disulphide, and the solution obtained is analysed by gas chromatography; the result in mg/m³ is compared with the NDS of 88 mg/m³ and the NDSCh of 353 mg/m³. Lowest determinable concentration according to the card — 8.8 mg/m³. WE DO NOT GIVE details of the standard — we did not have its text; the 2009 CIOP procedure is described separately.

Applications

• Workplace air — dichloromethane — in the current scopes of 6 laboratories (one item suspended until 07.12.2026)
• Assessment of occupational exposure against the NDS of 88 mg/m³ and the NDSCh of 353 mg/m³, "skin" notation (Journal of Laws 2026 item 447, item 165 of the list)

Key parameters

Standard

Standard number

PN-Z-04437:2011

Title (PL)

Ochrona czystości powietrza — Oznaczanie dichlorometanu na stanowiskach pracy metodą chromatografii gazowej

Title (EN)

Air purity protection — Determination of dichloromethane at workplaces by gas chromatography

Step-by-step procedure

1. Sampling

   Adsorption of vapours on activated or modified charcoal; WE DO NOT GIVE parameters of the standard.

2. Desorption

   With carbon disulphide, separately from each sorbent layer (CIOP procedure).

3. Analysis

   Gas chromatography; in the CIOP procedure — GC-FID, calibration curve from six solutions, desorption efficiency for each batch of sorbent.

4. Result and assessment

   Concentration in mg/m³; comparison with the NDS of 88 mg/m³ and the NDSCh of 353 mg/m³ (Journal of Laws 2026 item 447); lowest determinable concentration 8.8 mg/m³.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Carbon disulphide and dichloromethane — according to the CIOP procedure, work with organic solvents is carried out in an efficiently working fume hood
• TECHNICAL NOTE: the AB 1226 item is suspended until 07.12.2026; a bottom limit below 8.8 mg/m³ requires conditions different from those in the standard

Frequently asked questions