🌿 Formaldehyde in workplace air — colorimetric method with chromotropic acid; MAC (NDS) 0.37 mg/m³ (0.3 ppm), STEL (NDSCh) 0.74 mg/m³, "skin" notation; PN-Z-04045-04:1976 (withdrawn 23-08-2006, replaced by PN-Z-04045-12:2006)

Environment PN-Z-04045-04

Overview

WHAT THE STANDARD COVERS. The PKN card of PN-Z-04045-04:1976 has no "Scope" field — only the title speaks of the method: "Air purity protection -- Tests for aldehydes content -- Determination of formaldehyde at workplaces by the colorimetric method with chromotropic acid" (our translation). The card gives no limit of quantification. We did not have the text of the standard (2 pages). Part 02 of the same series (method with phenylhydrazine) is described in a separate entry of this database (formaldehyde in workplace air according to PN-Z-04045-02).

NDS VALUES (list in the annex to the regulation of 26 March 2026, Journal of Laws 2026 item 447). Item 260: "Formaldehyde [50-00-0]" with footnote 7 — NDS 0.37 mg/m³ (0.3 ppm), NDSCh 0.74 mg/m³ (0.6 ppm), "skin" notation; footnote 7: "The substance may have a sensitising effect on the skin".

STATUS (cards as of 04.10.2026). The card of PN-Z-04045-04:1976 (Polish version) has the heading "Withdrawn and replaced by PN-Z-04045-12:2006": published 04-06-1976, withdrawal date 23-08-2006, 2 pages, price group A, Health, Environment and Medicine Sector, KT 159 Chemical and Dust Hazards in the Working Environment, ICS 13.040.30, "Replaces PN-Z-04034:1966", "Replaced by PN-Z-04045-12:2006". The card of the successor — PN-Z-04045-12:2006 "… Part 12: Determination of formaldehyde at workplaces by gas chromatography with passive sampling" — has no "Withdrawn" heading: published 23-08-2006 (the day the old standard was withdrawn), 8 pages, "Replaces PN-Z-04045-04:1976"; its scope in full (our translation): "A method is given consisting in absorption of formaldehyde on a paper filter coated with 2,4-dinitrophenylhydrazine, desorption of the 2,4-dinitrophenylhydrazone formed in the reaction with acetonitrile and analysis of the solution obtained by gas chromatography. The lowest concentration of formaldehyde that can be determined by this method is 0.008 mg/m3" (the Polish card contains typing errors, which we do not reproduce in translation). The PKN search for "formaldehydu" (04.10.2026) shows only PN-Z-04045-12:2006 as current for workplaces; parts 02:1976 and 08:1990 are labelled "Withdrawn".

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 04045-04 (with a hyphen, full stop or slash before the part number) appears in 7 records at 6 laboratories; in the current PCA documents (read on 03.10.2026; issues from 29.10.2025 to 24.09.2026) — in 7 rows at the same laboratories; 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. Written forms: "PN-Z-04045-04:1976" — AB 340 and AB 1004 (working environment); "PN-76/Z-04045.04" — AB 618 and the second item of AB 1004 (waste gases, "excluding pt. 7"); "PN-76/Z-04045-04" — AB 833 and AB 865; "PN-76/Z-04045/04" — AB 1257. The "Laboratories" tab finds entries beginning with the query entered: "PN-Z-04045-04" shows 2 laboratories, "PN-76/Z-04045.04" — 2 (AB 1004 under two queries), "PN-76/Z-04045-04" — 2, "PN-76/Z-04045/04" — 1, 6 in total, the same in the copy and on the production server labcoda.pl (tab queries of 04.10.2026). The successor PN-Z-04045-12 is not cited by any laboratory in the database copy or in the current PCA documents (positive control with the same pattern: part 02 — in the documents of 21 laboratories). The entry on part 02 (read on 23.09.2026) gives "5 items" for part 04 — counted then with a narrower pattern; the present measurement covers all part-number separators.

WHAT THE LABORATORIES TEST (database copy). Object: working environment — air (AB 340, AB 618, AB 865, AB 1004, AB 1257 — at AB 1257 samples collected into an absorbing solution); AB 833 — general environment, air samples collected into an absorbing solution; AB 1004 also has a second item for waste gases. Quantity: concentration (content) of formaldehyde. Ranges in mg/m³: 0.025–2.00 (AB 865), 0.028–1.389 (AB 1257), 0.03–10.0 (AB 1004, waste gases), 0.04–6.4 (AB 340), 0.05–10.0 (AB 1004, working environment), 0.1–5.0 (AB 618); AB 833 — 0.004–2.5 mg per sample. Technique: spectrophotometric method — all 6 laboratories.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — status: the standard has been withdrawn since 23-08-2006 and has a current successor with a different technique (2,4-dinitrophenylhydrazine, gas chromatography); 6 laboratories have the old standard in scopes issued from October 2025, and none has the successor. Second — sensitivity against the NDS: the NDS is 0.37 mg/m³, and the card of the old standard gives no limit of quantification; the bottom limits of the laboratories (from 0.025 to 0.1 mg/m³) are from about 7 % to about 27 % of the NDS — when measuring against the NDSCh of 0.74 mg/m³ and the NDS, what counts is whether the range covers this, not just the number of the standard. Third — two parts of the series on formaldehyde: part 02 (phenylhydrazine) and part 04 (chromotropic acid) use different reagents; the shortened number "PN-76/Z-04045" merges them in searching. Fourth — object: AB 833 applies the workplace standard to the general environment, and AB 1004 — to waste gases ("excluding pt. 7"); for these matrices the NDS is not a reference value. Fifth — skin and sensitisation: a measurement in air does not cover absorption through the skin or the sensitising effect.

WHAT WE DO NOT GIVE. We did not have the text of the standard, and the card has no "Scope" field — we do not give the sampling method, the absorbing solution, the conditions of the reaction with chromotropic acid, the wavelength, the limit of quantification or calculations; we do not know the content of point 7 excluded by AB 1004. We did not have the text of PN-Z-04045-12:2006 either — we describe it only from its card.

Method principle

Formaldehyde in workplace air is determined by the colorimetric method with chromotropic acid (title of the standard); the result in mg/m³ is compared with the NDS of 0.37 mg/m³ and the NDSCh of 0.74 mg/m³. The card has no "Scope" field. The standard is withdrawn (23-08-2006) and replaced by PN-Z-04045-12:2006 (2,4-dinitrophenylhydrazine on a filter, passive sampling, gas chromatography); WE DO NOT GIVE details of either — we did not have the texts of the standards.

Applications

• Workplace air — formaldehyde — in the current scopes of 6 laboratories, despite the withdrawal of the standard in 2006
• Assessment of occupational exposure against the NDS of 0.37 mg/m³ and the NDSCh of 0.74 mg/m³, "skin" notation (Journal of Laws 2026 item 447, item 260 of the list)
• For comparison: the current PN-Z-04045-12:2006 (gas chromatography, passive sampling) — in the scope of no laboratory

Key parameters

Standard

Standard number

PN-Z-04045-04:1976

Title (PL)

Ochrona czystości powietrza — Badania zawartości aldehydów — Oznaczanie formaldehydu na stanowiskach pracy metodą kolorymetryczną z kwasem chromotropowym

Title (EN)

Air purity protection — Tests for aldehydes content — Determination of formaldehyde at workplaces by the colorimetric method with chromotropic acid

Step-by-step procedure

1. Status

   PN-Z-04045-04:1976 withdrawn on 23-08-2006, replaced by PN-Z-04045-12:2006 (cards as of 04.10.2026).

2. Sampling

   WE DO NOT GIVE the sampling method (card without a "Scope" field); in the scopes of some laboratories — an absorbing solution.

3. Reaction and measurement

   Reaction with chromotropic acid, colorimetric measurement (title of the standard).

4. Result and assessment

   Concentration in mg/m³; comparison with the NDS of 0.37 mg/m³ and the NDSCh of 0.74 mg/m³ (Journal of Laws 2026 item 447).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Formaldehyde — according to footnote 7 of the list the substance may have a sensitising effect on the skin; chemical laboratory safety rules
• TECHNICAL NOTE: standard withdrawn since 2006 with a current successor that no laboratory cites

Frequently asked questions