🌿 Hydrogen peroxide in workplace air — spectrophotometric method (in the CIOP procedure: absorption in water in a fritted bubbler, reaction with iron(II) ions and xylenol orange, measurement at 560 nm); lowest determinable concentration according to the standard 0.04 mg/m³, MAC (NDS) 0.4 mg/m³, NDSCh 0.8 mg/m³; PN-Z-04548:2023-03

Environment PN-Z-04548

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card, in full (our translation): "This standard gives a method for determining hydrogen peroxide (CAS No. 7722-84-1) in workplace air using a spectrophotometric method. The method is used in the control of sanitary and hygienic conditions. The lowest concentration of hydrogen peroxide that can be determined under the air sampling and determination conditions described in the standard is 0.04 mg/m3." We did not have the text of the standard (8 pages).

ACCORDING TO THE CIOP PROCEDURE (W. Mysur, N. Kucharska, M. Bonczarowska, S. Brzeźnicki, Nofer Institute of Occupational Medicine, Łódź, "Hydrogen peroxide. Determination in workplace air with spectrophotometric method", Podstawy i Metody Oceny Środowiska Pracy 2021, no. 3(109), pp. 161–171 — read in full). The procedure in the appendix of the article begins with the words "This standard gives a method for determining the content of hydrogen peroxide…" and has the same lowest determinable concentration as the card (0.04 mg/m³ for 10 l of air); the article does not, however, say that it is the text of PN-Z-04548:2023-03, so the figures below are figures of the procedure in the article. Principle: hydrogen peroxide from air passed through a fritted bubbler with 10 ml of water reacts with iron(II) ions, and the oxidised iron(III) ions form a coloured complex with xylenol orange measured spectrophotometrically at 560 nm. Sampling according to PN-Z-04008-7: not less than 10 l of air at a constant flow of 3.0 l/h; samples kept in a refrigerator remain stable for no longer than 2 days (after 3 days, 69–86 % of the content in the tests). Determination: 0.5 ml of sample + 0.25 ml of methanol + 0.25 ml of FOX reagent (xylenol orange, sorbitol and Mohr's salt dissolved in sulphuric acid), incubation for at least 30 min at room temperature; calibration curve 0.04–0.80 µg/ml in the standard solutions; X = m/V·20 (20 — dilution factor). Validation according to PN-EN 482: range 0.04–0.8 mg/m³ for a 10 l sample (about 0.1–2 NDS values), r = 0.9992, mean recovery from the bubbler 1.0, expanded uncertainty 19.6 %. Reason for the new method: the earlier CIOP method of 1997 (complex of iron ions with thiocyanate ions) covered 0.5–4 mg/m³ and, after the NDS was lowered from 1.5 to 0.4 mg/m³, no longer met PN-EN 482. In the article the Polish abstract gives linearity of 0.02–0.4 µg/ml and the English one 0.2–4.0 µg/ml — both with the same range of 0.04–0.8 mg/m³.

NDS VALUES (list in the annex to the regulation of 26 March 2026, Journal of Laws 2026 item 447). Item 400: "Hydrogen peroxide [7722-84-1]" — NDS 0.4 mg/m³, NDSCh 0.8 mg/m³, without the "skin" notation. The lowest determinable concentration according to the card, 0.04 mg/m³, is 10 % of the NDS.

STATUS (card as of 04.10.2026). The card of PN-Z-04548:2023-03 (Polish version) has no "Withdrawn" heading — the standard is CURRENT: published 29-03-2023, 8 pages, price group D, Health, Environment and Medicine Sector, KT 159 Chemical and Dust Hazards in the Working Environment, ICS 13.040.30; national standard, without the fields "Implements" and "Supersedes". The PKN search for "PN-Z-04548" (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 04548 appears in 6 records at 6 laboratories; in the current PCA documents (read on 03.10.2026; issues from 08.01.2026 to 03.09.2026) — 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 item is suspended and no document repeats pages. All entries read "PN-Z-04548:2023-03". AB 409 has the item in a flexible accreditation scope (mark "E"), and directly above it a separate item for hydrogen peroxide with a method from "Podstawy i Metody Oceny Środowiska Pracy" (no year in the document). The "Laboratories" tab (query "PN-Z-04548") shows all 6 laboratories — 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, air samples collected into an absorbing solution. Quantity: concentration (content) of hydrogen peroxide. Ranges in mg/m³: 0.04–2.1 (AB 647), 0.04–2.67 (AB 849), 0.04–3.3 (AB 882), 0.04–4.2 (AB 1144), 0.040–1.6 (AB 802); AB 409 — no range in the item. Technique: spectrophotometric method — all laboratories.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — upper limit: the CIOP procedure was validated for 0.04–0.8 mg/m³ (10 l of air); five laboratories state an upper limit from 1.6 to 4.2 mg/m³ — the scopes do not show how it was obtained (sample volume, dilution), and WE DO NOT GIVE this. All five laboratories with a range state a bottom limit of 0.04 mg/m³, as on the card. Second — sample stability: according to the CIOP procedure, samples in a refrigerator are stable for at most 2 days. Third — other peroxides: according to the article the colour reaction of xylenol orange occurs with iron ions oxidised by hydrogen peroxide "(or other peroxides)"; the article states that the method allows determination in the presence of co-occurring substances, but does not name them. Fourth — two methods in one laboratory: AB 409 also has an item for hydrogen peroxide with a method from the CIOP quarterly — the report should state which was used. Fifth — the NDSCh of 0.8 mg/m³ requires a short-term measurement, the conditions of which WE DO NOT GIVE.

WHAT WE DO NOT GIVE. We did not have the text of the standard — we give the figures of the procedure from the CIOP article and label them as such; we do not attribute them to the standard. We do not state which method from the CIOP quarterly the second AB 409 item cites.

Method principle

Hydrogen peroxide from workplace air is absorbed in water in a fritted bubbler. In the CIOP procedure it oxidises iron(II) ions to iron(III), which form a coloured complex with xylenol orange (FOX reagent with sorbitol and Mohr's salt in sulphuric acid); after at least 30 min the absorbance is measured at 560 nm and the mass of hydrogen peroxide is read from the calibration curve. The result in mg/m³ is compared with the NDS of 0.4 mg/m³ and the NDSCh of 0.8 mg/m³; lowest determinable concentration according to the card of the standard — 0.04 mg/m³.

Applications

• Workplace air — hydrogen peroxide — in the scopes of 6 laboratories
• Assessment of occupational exposure against the NDS of 0.4 mg/m³ and the NDSCh of 0.8 mg/m³ (Journal of Laws 2026 item 447, item 400 of the list)

Key parameters

Standard

Standard number

PN-Z-04548:2023-03

Title (PL)

Ochrona czystości powietrza — Oznaczanie nadtlenku wodoru na stanowiskach pracy metodą spektrofotometryczną

Title (EN)

Air purity protection — Determination of hydrogen peroxide at workplaces by spectrophotometry

Step-by-step procedure

1. Status and scope

   PN-Z-04548:2023-03 current (card as of 04.10.2026); lowest determinable concentration 0.04 mg/m³.

2. Sampling

   According to PN-Z-04008-7: at least 10 l of air through a bubbler with 10 ml of water at 3.0 l/h; storage in a refrigerator up to 2 days (CIOP procedure).

3. Colour reaction

   0.5 ml of sample + 0.25 ml of methanol + 0.25 ml of FOX reagent, at least 30 min at room temperature (CIOP procedure).

4. Measurement

   Absorbance at 560 nm against a blank; calibration curve from the working solutions (CIOP procedure).

5. Result and assessment

   X = m/V·20 in mg/m³ (CIOP procedure); comparison with the NDS of 0.4 mg/m³ and the NDSCh of 0.8 mg/m³ (Journal of Laws 2026 item 447).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Operations with organic solvents — with personal protective equipment under a fume hood; residues handed over for disposal (CIOP procedure)
• TECHNICAL NOTE: the CIOP procedure was validated up to 0.8 mg/m³ (10 l); samples stable for at most 2 days in a refrigerator

Frequently asked questions