🌿 Formic acid in workplace air — reduction with magnesium to formaldehyde, reaction with chromotropic acid in sulphuric acid, spectrophotometry; smallest amount determined according to the standard 0.06 mg/m³, MAC (NDS) 5 mg/m³, STEL (NDSCh) 15 mg/m³; PN-Z-04196-02:1988 (withdrawn 10-09-2015)
In short
Two-page Polish standard of 1988 with a method for determining formic acid in workplace air: formic acid is reduced with magnesium in the presence of hydrochloric acid to formaldehyde, which is determined spectrophotometrically with chromotropic acid; the smallest amount determined according to the PKN card is 0. The test is performed according to PN-Z-04196-02:1988; STATUS (card as of 04.10.2026): PN-Z-04196-02:1988 WITHDRAWN — withdrawal date 10-09-2015; the card names no replacing standard; PN-Z-04196-01:1988 also withdrawn. The procedure comprises 4 steps; it is used for: Workplace air — formic acid — in the current scopes of 6 laboratories, despite the withdrawal of the standard, Assessment of occupational exposure against the NDS of 5 mg/m³ and the NDSCh of 15 mg/m³ (Journal of Laws 2026 item 447, item 343 of the list).
At a glance
- Standard: PN-Z-04196-02:1988
- Category: Environment
- Procedure steps: 4
- STATUS (card as of 04.10.2026): PN-Z-04196-02:1988 WITHDRAWN — withdrawal date 10-09-2015; the card names no replacing standard; PN-Z-04196-01:1988 also withdrawn
- Edition (from the PKN card): PN-Z-04196-02:1988, Polish version; published 28-06-1988, 2 pages, KT 159 Chemical and Dust Hazards in the Working Environment, ICS 13.040.30
- Smallest amount determined (card): 0.06 mg/m³
Overview
WHAT THE STANDARD COVERS. Scope from the PKN catalogue card, in full (our translation): "The method consists in reduction of formic acid with magnesium in the presence of hydrochloric acid to formaldehyde, followed by reduction of formaldehyde with chromotropic acid in a sulphuric acid medium. The absorbance is measured spectrophotometrically. The smallest amount of formic acid determined is 0.06 mg in 1 cubic metre of air. The method should not be used in the presence of phenol, cresol and acrolein" (no full stop at the end on the card; the wording "reduction of formaldehyde with chromotropic acid" is the card's). We did not have the text of the standard (2 pages); the CIOP index of methods from 2000–2017 lists no article on formic acid (searched on 04.10.2026).
NDS VALUES (list in the annex to the regulation of 26 March 2026, Journal of Laws 2026 item 447). Item 343: "Formic acid [64-18-6]" — NDS 5 mg/m³, NDSCh 15 mg/m³, no "skin" notation. The smallest amount determined according to the card, 0.06 mg/m³, is about 1 % of the NDS.
STATUS (card as of 04.10.2026). The card of PN-Z-04196-02:1988 (Polish version) has the heading "Withdrawn": published 28-06-1988, withdrawal date 10-09-2015, 2 pages, price group A, Health, Environment and Medicine Sector, KT 159 Chemical and Dust Hazards in the Working Environment, ICS 13.040.30; the card does not name a replacing standard. The PKN search for "PN-Z-04196" (04.10.2026) returns two parts of the series — PN-Z-04196-01:1988 (general provisions and scope of the standard) and PN-Z-04196-02:1988 — both labelled "Withdrawn"; the search for "kwasu mrówkowego" shows no current standard for formic acid at workplaces.
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 04196-02 (with a hyphen, full stop or slash before the part number) appears in 6 records at 6 laboratories; in the current PCA documents (read on 03.10.2026; issues from 26.01.2026 to 28.07.2026 — all issued after the withdrawal of the standard) — 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. Old form "PN-88/Z-04196/02" — AB 632 (next to instruction IB-66 edition 1 of 04.03.2019), AB 647, AB 849, AB 882; "PN-88/Z-04196.02" — AB 875; "PN-Z-04196-02:1988" — AB 1642. "Laboratories" tab: "PN-88/Z-04196/02" shows 4 laboratories, "PN-88/Z-04196.02" — 1, "PN-Z-04196-02" — 1, 6 in total, the same in the copy and on the production server labcoda.pl (tab queries of 04.10.2026).
WHAT THE LABORATORIES TEST (database copy). Object: working environment — air, samples collected into an absorbing solution (at AB 882 — air samples without further description). Quantity: concentration (content) of formic acid. Ranges in mg/m³: 0.08–30 (AB 647), 0.15–30 (AB 849), 0.33–40 (AB 875), 0.38–40.8 (AB 882), 0.48–30.8 (AB 632), 0.490–16.60 (AB 1642). Technique: spectrophotometric method — all 6 laboratories.
WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — status: the standard has been withdrawn since 10-09-2015, and the PKN search shows no other standard for formic acid; 6 laboratories have it in scopes issued in 2026 — the client should know that the result is produced according to a standard withdrawn from the PKN catalogue. Second — interferences: according to the card the method is not used in the presence of phenol, cresol and acrolein; a report from a site where these substances occur should explain this. Third — what the method measures: formic acid is determined indirectly — as formaldehyde after reduction with magnesium; how the standard deals with formaldehyde present in the air tested is not stated on the card, and WE DO NOT GIVE it. Fourth — limit of quantification: the bottom limits of all 6 laboratories (from 0.08 to 0.490 mg/m³) are higher than the smallest amount determined according to the card (0.06 mg/m³) — on this point the ranges do not go beyond the standard. Fifth — the NDSCh of 15 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 do not give the absorbing solution, the volume and flow rate of air, the amounts of magnesium and acids, reaction conditions, the wavelength or calculations. We do not claim that another standard has replaced PN-Z-04196-02:1988 — PKN names none.
Method principle
Formic acid from workplace air is reduced with magnesium in the presence of hydrochloric acid to formaldehyde, followed, as the card states, by "reduction of formaldehyde with chromotropic acid in a sulphuric acid medium"; the absorbance is measured spectrophotometrically. The result in mg/m³ is compared with the NDS of 5 mg/m³ and the NDSCh of 15 mg/m³; smallest amount determined according to the card — 0.06 mg/m³. The method is not used in the presence of phenol, cresol and acrolein. The standard is withdrawn (10-09-2015); WE DO NOT GIVE details — we did not have the text of the standard.
Applications
- Workplace air — formic acid — in the current scopes of 6 laboratories, despite the withdrawal of the standard
- Assessment of occupational exposure against the NDS of 5 mg/m³ and the NDSCh of 15 mg/m³ (Journal of Laws 2026 item 447, item 343 of the list)
Key parameters
| Parameter | Value |
|---|---|
| STATUS (card as of 04.10.2026) | PN-Z-04196-02:1988 WITHDRAWN — withdrawal date 10-09-2015; the card names no replacing standard; PN-Z-04196-01:1988 also withdrawn |
| Edition (from the PKN card) | PN-Z-04196-02:1988, Polish version; published 28-06-1988, 2 pages, KT 159 Chemical and Dust Hazards in the Working Environment, ICS 13.040.30 |
| Smallest amount determined (card) | 0.06 mg/m³ |
| Limitation (card) | not to be used in the presence of phenol, cresol and acrolein |
| NDS / NDSCh (Journal of Laws 2026 item 447, item 343) | 5 mg/m³ / 15 mg/m³ |
| Coverage in accreditation scopes (read 04.10.2026) | 6 laboratories, 6 records in the database copy, 6 rows in PCA; ranges from 0.08 to 40.8 mg/m³; "Laboratories" tab (three written forms) — 6 in total, the same on the production server |
Standard
- Standard number
- PN-Z-04196-02:1988
- Title (PL)
- Ochrona czystości powietrza — Badania zawartości kwasu mrówkowego — Oznaczanie kwasu mrówkowego na stanowiskach pracy metodą spektrofotometryczną z kwasem chromotropowym
- Title (EN)
- Air purity protection — Tests for formic acid content — Determination of formic acid at workplaces by the spectrophotometric method with chromotropic acid
Step-by-step procedure
-
Status
PN-Z-04196-02:1988 withdrawn on 10-09-2015, with no named successor (card as of 04.10.2026).
-
Reduction
Formic acid is reduced with magnesium in the presence of hydrochloric acid to formaldehyde (PKN card).
-
Colour reaction and measurement
Formaldehyde with chromotropic acid in a sulphuric acid medium (card: "reduction of formaldehyde with chromotropic acid"), spectrophotometric measurement.
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Result and assessment
Concentration in mg/m³; comparison with the NDS of 5 mg/m³ and the NDSCh of 15 mg/m³ (Journal of Laws 2026 item 447); smallest amount determined 0.06 mg/m³.
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Spectrophotometer | Absorbance measurement after reaction with chromotropic acid (PKN card); WE DO NOT GIVE the wavelength | — |
Reagents, media and consumables
| Reagent | CAS | Details |
|---|---|---|
| Magnesium and hydrochloric acid | — | For reducing formic acid to formaldehyde (PKN card) |
| Chromotropic acid in sulphuric acid | — | For the colour reaction with formaldehyde (PKN card) |
Health and safety (OHS)
- Hydrochloric acid, sulphuric acid and magnesium — chemical laboratory safety rules
- TECHNICAL NOTE: standard withdrawn on 10-09-2015; not to be used in the presence of phenol, cresol and acrolein
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-Z-04196-02:1988 — “Air purity protection — Tests for formic acid content — Determination of formic acid at workplaces by the spectrophotometric method with chromotropic acid”.
How does this method work?
Formic acid from workplace air is reduced with magnesium in the presence of hydrochloric acid to formaldehyde, followed, as the card states, by "reduction of formaldehyde with chromotropic acid in a sulphuric acid medium"; the absorbance is measured spectrophotometrically. The result in mg/m³ is compared with the NDS of 5 mg/m³ and the NDSCh of 15 mg/m³; smallest amount determined according to the card — 0.
What is the measuring range and accuracy?
STATUS (card as of 04.10.2026): PN-Z-04196-02:1988 WITHDRAWN — withdrawal date 10-09-2015; the card names no replacing standard; PN-Z-04196-01:1988 also withdrawn; Edition (from the PKN card): PN-Z-04196-02:1988, Polish version; published 28-06-1988, 2 pages, KT 159 Chemical and Dust Hazards in the Working Environment, ICS 13.040.30; Smallest amount determined (card): 0.06 mg/m³; Limitation (card): not to be used in the presence of phenol, cresol and acrolein.
How long does the test take?
The procedure comprises 4 steps. The standard does not give a duration for every stage — the laboratory's own procedure decides.
What equipment is required?
Spectrophotometer.
Where is this test used?
Workplace air — formic acid — in the current scopes of 6 laboratories, despite the withdrawal of the standard; Assessment of occupational exposure against the NDS of 5 mg/m³ and the NDSCh of 15 mg/m³ (Journal of Laws 2026 item 447, item 343 of the list).
What safety precautions apply?
Hydrochloric acid, sulphuric acid and magnesium — chemical laboratory safety rules; TECHNICAL NOTE: standard withdrawn on 10-09-2015; not to be used in the presence of phenol, cresol and acrolein.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-Z-04196-02.