⛽ Red dye (expressed as Solvent Red 19), Solvent Red 164, Solvent Blue 35 and the Solvent Yellow 124 marker in light heating oil and diesel fuel — three spectrophotometric methods A, B, C in the range 1.0–15.0 mg/l; PN-C-04426:2013-07 (withdrawn standard)

Petrochemistry PN-C-04426

Overview

WHAT THE STANDARD COVERS. The "Scope" field of the PKN card of PN-C-04426:2013-07, in full: "This standard gives methods for determining the content of the Solvent Yellow 124 marker in light heating oil and in diesel fuel, which may also be used for navigation purposes (marine fuel); the content of the Solvent Red 164 dye and of red dye expressed as Solvent Red 19 in light heating oil and diesel fuel; the content of the Solvent Blue 35 dye in light heating oil and in diesel fuel used for navigation purposes (marine fuel), for the following concentration ranges: – Method A - Determination of the content of red dye expressed as Solvent Red 19 and of the Solvent Yellow 124 marker from 1.0 mg/l to 15.0 mg/l; – Method B - Determination of the content of the Solvent Red 164 dye from 1.0 mg/l to 15.0 mg/l; – Method C - Determination of the content of the Solvent Blue 35 dye from 1.0 mg/l to 15.0 mg/l. The methods for determining red dyes given in this standard do not serve to identify them. Before the determination is started, the type of dye used in the product tested has to be known" (our translation). We did not have the text of the standard (18 pages).

STATUS (PKN card as of 27.10.2026). The card of PN-C-04426:2013-07 (Polish version) bears the label "Withdrawn" and the line "Withdrawal date: 17-09-2025"; publication 30-07-2013, 18 pages, Chemistry Sector, KT 222/PK 1 Liquid Fuels, ICS 75.160.20. The card has no "Replaced by" field — the PKN search (search term "PN-C-04426", 27.10.2026) returns only this one standard, without a successor.

REGULATION. Regulation of the Minister of Finance of 28 November 2022 on the marking and colouring of energy products (Journal of Laws 2022 item 2633, "in force" in the ELI database of the Sejm, read on 27.10.2026). § 2: the ACCUTRACE™ PLUS marker with butoxybenzene (CAS 1126-79-0) is used for marking, and for colouring — Solvent Red 19 (CAS 6368-72-5) for heating oils and for diesel fuels intended for heating purposes, and Solvent Blue 35 (CAS 17354-14-2) for oils used for navigation purposes, including fishing trips; other dyes of the same type with a comparable colour effect are allowed. A product is regarded as correctly marked and coloured when it contains 9.5–14.25 mg of butoxybenzene per litre and at least 6.3 mg/l of Solvent Red 19 (heating oils) or at least 6.0 mg/l of Solvent Blue 35 (navigation). § 3: until 18 January 2024 marking with the Solvent Yellow 124 marker (CAS 34432-92-3) in an amount of 6.0–9.0 mg/l was allowed. The regulation does not specify a method of determination.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database refreshed from the production server on 27.10.2026 and current PCA documents downloaded on that day). Number 04426 appears in 20 records at 7 Polish laboratories: AB 009, AB 103, AB 387, AB 474, AB 484, AB 656, AB 773. The current PCA documents confirm the standard at six of them (18 rows); AB 474 (ORLEN Laboratorium, Gdańsk Refinery Laboratory, accreditation valid until 16-12-2027) has no scope document on the PCA website on 27.10.2026. No entry is suspended. Forms: "PN-C-04426:2013-07" with the method letter (AB 009, AB 103, AB 474, AB 484, AB 656, AB 773) and "PN-C-04426 excluding methods B and C" without the year (AB 387). The "Laboratories" tab ("PN-C-04426") shows these 7 laboratories (tab query on labcoda.pl, 27.10.2026).

WHAT THE LABORATORIES TEST (database copy and PCA documents). All entries are the spectrophotometric method. Method A — Solvent Red 19 (red dye): AB 009 (0.1–15.0 mg/l, light heating oil and diesel fuel), AB 103 (1.0–15.0 mg/l), AB 387 (four entries, also "red dye expressed as Solvent Red 19", without a range), AB 474, AB 484 (1.0–15.0 and 1.0–10.0 mg/l), AB 656 (1.0–15.0 mg/l, also biofuels), AB 773 (1.0–11.0 mg/l); method A — the Solvent Yellow 124 marker: AB 009 (0.1–2.0 mg/l, diesel fuel). Method B — Solvent Red 164: AB 009 (0.6–2.0 mg/l), AB 484 (1.0–15.0 mg/l). Method C — Solvent Blue 35: AB 009 (0.1–15.0 mg/l, diesel fuel and marine fuel), AB 474, AB 484 and AB 656 (1.0–15.0 mg/l).

ALONGSIDE THIS STANDARD (database copy, 27.10.2026). Dyes and markers in fuels are in the scopes of the same 7 laboratories; AB 484 also determines Solvent Red 19 in light heating oil and its blends according to DIN 51430:2018-02 — by high-performance liquid chromatography with spectrophotometric detection (HPLC-UV/VIS). The current marker — butoxybenzene (ACCUTRACE™ PLUS) — is determined according to documents other than this standard: AB 484 and AB 656 according to ILIADe 606:2024, AB 009 according to procedure PB-25/TA/23, AB 773 according to procedure PB-2.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — status: the standard has been withdrawn since 17-09-2025 and has no successor, while the accreditation scopes of seven laboratories still cite it; it is worth stating the edition in the report and that the standard is withdrawn. Second — identification: the methods for red dyes measure the content expressed as a specified dye and do not recognise the dye — the type of dye has to be known before the determination ("Scope" field). Third — range: the standard covers 1.0–15.0 mg/l; the lower limits of 0.1 and 0.6 mg/l (AB 009) lie below the range of the standard. Fourth — marker: since 19 January 2024 the regulation no longer allows Solvent Yellow 124 (the current marker is butoxybenzene, determined by other methods), so a determination of Solvent Yellow 124 by method A does not answer the question of correct marking under the current regulation. Fifth — regulatory requirement: Solvent Red 19 at least 6.3 mg/l and Solvent Blue 35 at least 6.0 mg/l lie within the range of methods A and C.

WHAT WE DO NOT GIVE. We did not have the text of the standard: we do not give the wavelengths, the preparation of samples and standard solutions, how the result is expressed as Solvent Red 19, formulas or precision.

Method principle

The content of a dye or marker in light heating oil, diesel fuel and marine fuel is determined spectrophotometrically, by each of three methods in the range 1.0–15.0 mg/l: A — red dye expressed as Solvent Red 19 and the Solvent Yellow 124 marker, B — Solvent Red 164, C — Solvent Blue 35. The methods for red dyes do not identify the dye — its type must be known before the determination ("Scope" field of the PKN card). WE DO NOT GIVE details of the methods.

Applications

• Light heating oil, diesel fuel and marine fuel — content of dyes and marker 1.0–15.0 mg/l ("Scope" field of the PKN card)
• Checking colouring against Journal of Laws 2022 item 2633: Solvent Red 19 ≥ 6.3 mg/l, Solvent Blue 35 ≥ 6.0 mg/l
• In accreditation scopes: 7 Polish laboratories, all by the spectrophotometric method; despite the withdrawal of the standard

Key parameters

Standard

Standard number

PN-C-04426:2013-07 (wersja polska; norma wycofana 17-09-2025, bez normy zastępującej)

Title (PL)

Ciekłe przetwory naftowe — Spektrofotometryczne metody oznaczania znacznika Solvent Yellow 124 oraz czerwonego i niebieskiego barwnika w lekkich olejach opałowych i olejach napędowych

Title (EN)

Liquid petroleum products — Spectrophotometric methods for the determination of the Solvent Yellow 124 marker and of red and blue dyes in light heating oils and diesel fuels

Step-by-step procedure

1. Type of dye

   Before the determination the type of dye in the product has to be known — the methods for red dyes do not identify it ("Scope" field).

2. Choice of method

   A — red dye as Solvent Red 19 (and the Solvent Yellow 124 marker), B — Solvent Red 164, C — Solvent Blue 35; range 1.0–15.0 mg/l.

3. Measurement

   Spectrophotometrically; WE DO NOT GIVE details.

4. Result and assessment

   Content in mg/l; assessment of colouring against ≥ 6.3 mg/l of Solvent Red 19 or ≥ 6.0 mg/l of Solvent Blue 35 (Journal of Laws 2022 item 2633). Standard withdrawn on 17-09-2025 (PKN card, 27.10.2026).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• TECHNICAL NOTE: standard withdrawn on 17-09-2025 without a successor — when citing it, give the edition and status
• TECHNICAL NOTE: the determination of red dye does not recognise the dye — the result is expressed as Solvent Red 19

Frequently asked questions