Cr(VI) in Paint and Coatings: A Planned Approach to Investigation and Remediation #

Cr(VI) is not found on steel alone. In practice, SEEF encounters chromium-6 in paint on every common construction substrate: steel and cast iron, wood (in a significant proportion of sampled cases), aluminum, and concrete. Sometimes as a pigment for color, sometimes as an anti-corrosive additive in a primer or intermediate layer. For maintenance, renovation, and demolition work on these painted surfaces, the work is generally planned in advance: it is known beforehand that work will take place, and which components are involved. This makes it possible to carry out a preliminary investigation, choose the right control measures, and validate exposure during execution. This page explains how that works.

What Is Cr(VI) in Paint? #

Cr(VI) compounds were added on a large scale, for decades, to paint systems for a wide range of substrates: ferrous metals (steel, cast iron), non-ferrous metals (aluminum, sometimes copper and magnesium), wood, and concrete. The addition usually serves one of two purposes: pigmentation for color, or anti-corrosive function in a primer or intermediate layer. The most common Cr(VI) compounds in old paint systems are:

• Lead chromate (PbCrO₄): mainly used as a pigment in primers and topcoats. Contains both Cr(VI) and lead. Found in old paint systems on steel, wood, and concrete.
• Lead sulfochromate (PbCrO₄·PbSO₄ and variants): used in applications where an opaque color was desired, on various substrates.
• Zinc chromate (ZnCrO₄): in shop primers and zinc-rich primers, particularly on steel and galvanized surfaces.
• Strontium chromate (SrCrO₄): the anti-corrosive pigment of choice for aluminum, particularly in aviation, marine, military applications, and architectural aluminum coatings. Also used in industrial coatings on steel.
• Barium chromate (BaCrO₄): used less frequently, in specific industrial and aviation applications.

Two important caveats for anyone assessing whether a paint layer is suspect. First, the substrate: Cr(VI) is not found on steel alone. We encounter it most frequently in practice on steel, but on wood SEEF finds Cr(VI) in a significant proportion of sampled cases; on aluminum, it has been virtually a standard ingredient in anti-corrosive primers; and on concrete it occurs in floor coatings and industrial protective systems. Second, the color: Cr(VI) occurs in every color. It is a persistent misunderstanding that only red, yellow, or orange layers are suspect. Cr(VI) can be present as a pigment in a colored layer, but equally as an anti-corrosive additive beneath a layer of an entirely different color. Selecting samples based on substrate or color is therefore not a reliable way to determine the presence or absence of Cr(VI); only laboratory analysis of the material provides a definitive answer.

Where Do You Encounter Cr(VI) in Paint? #

The typical sectors where SEEF carries out Cr(VI) investigations on old paint layers, with the common substrates per sector:

Preliminary Investigation: How Do You Know If It’s in Your Paint? #

For planned work, the preliminary investigation is the foundation. A few starting points:

First Indication from Records #

Construction year, owner, supplier, and old technical files serve as a first filter, but never provide a conclusive answer. Since various sunset dates between 2015 and 2019, the most commonly used Cr(VI) compounds may only be placed on the European market under REACH authorisation. Lead chromate and lead sulfochromate have a sunset date of 22 May 2015, chromium trioxide 21 September 2017, and strontium chromate 22 January 2019. For material predating these dates, Cr(VI) can statistically be expected to be present.

What a first filter alone cannot capture is material imported from outside the EU. In practice, SEEF has found high Cr(VI) concentrations in material for which the accompanying Safety Data Sheet (SDS) did not mention Cr(VI). The reasons behind this can vary, ranging from different analytical practices in the country of origin to an SDS that simply does not reflect the full composition. An SDS check alone is therefore not conclusive proof of absence; only analysis of the material itself provides certainty. This applies to both old and recently supplied material.

Representative Sampling #

Cr(VI) is rarely found only in the top layer. On metal substrates, it is mostly present in the rust-inhibiting primer or an intermediate layer; on wood and concrete, it more often appears as a pigment in a colored layer within the system. A sample containing only the top layer can produce a false-negative result in both cases. For a correct preliminary investigation, the entire layer build-up is sampled: from the top layer down to the substrate, preserving the matrix. SEEF either samples on-site itself or provides instructions to the executing party. For interpretation, it is also important to establish whether multiple protective cycles are layered on top of each other; this regularly occurs on older steel structures, heritage wooden window frames, and aluminum facade cladding.

Laboratory Analysis: Matrix DP01 #

SEEF analyzes dry paint samples using matrix DP01, with the patented method WO2023219493. The method is resistant to the known interferences (zinc, iron, copper, aluminum) that lead to underestimation of Cr(VI) with standard methods. In zinc-rich matrices (galvanized coatings, zinc-rich primers, shop primers), this produces a substantial difference.

• Limit of Detection (LOD): approximately 0.5 mg Cr(VI) per kg dry paint.
• Limit of Quantification (LOQ): approximately 1.7 mg/kg.
• Two calibration ranges (low 0–100 µg/L, high 0–600 µg/L) so that both concentrations near the detection limit and high concentrations are reliably quantified without a dilution step.
• Cross-validated by nine analysts with no operator-dependent deviations.

Always Include Lead #

Lead chromate and lead sulfochromate contain both Cr(VI) and lead. Since 9 April 2026, the Dutch exposure limit for lead has been lowered to 0.03 mg/m³ TWA-8h, with a threshold for lead in a coating of 0.75% (previously 3.75%). In practice, it is rarely useful to investigate only Cr(VI) on a paint layer suspected of containing lead chromate: including lead in the same analysis avoids the need for a second round of work to justify additional lead-related control measures. For the legal background, see the page “Chromium-6 Legislation in the Netherlands.”

Beheersregime 2.0: The Dutch Sector Framework #

For planned maintenance of old steel protective coatings in Dutch infrastructure, Rijkswaterstaat, ProRail, and the Central Government Real Estate Agency have applied the Chromium-6 Management Regime (version 2.0) since April 2022. The framework replaces the earlier risk-class 1/2/3 approach, which in practice led to disproportionate, asbestos-remediation-like conditions. The regime was developed by PreventPartner and is largely based on exposure measurements carried out between 2019 and 2021, supplemented with expert judgment where measurements were lacking.

The Official Regime: A Work-Type Matrix Focused on Dust Control #

Beheersregime 2.0 is built around dust control per type of work, not around a classification of the Cr(VI) concentration in the material. The document states this explicitly: from a health perspective, determining the chromium-6 concentration in material samples adds no value to the choice of control measures. The underlying reasoning is that measurements show exposure to inhalable dust is the most critical factor in most operations, and that measures which sufficiently reduce dust also cover Cr(VI) exposure.

The regime therefore works with control-measure matrices per work-type category. The four main categories in the official document are:

• Working on the structure: cutting, sawing, thermal gouging, oxy-fuel cutting, hydraulic shearing, manual unbolting, pneumatic unbolting of chromated bolts, drilling, heat application, and removal of glazing bars.
• Cleaning: blowing with compressed air (discouraged), sweeping (discouraged, causes secondary exposure), industrial vacuuming, steam cleaning, and replacing filters in ventilation units.
• Removing paint and coating, dry methods: manual sanding, mechanical sanding with or without on-tool extraction, grit blasting (single-use or recyclable grit), vacuum blasting, sponge blasting, laser cleaning, and induction cleaning.
• Removing paint and coating, wet methods: manual wet sanding, high-pressure water blasting, wet blasting with water and grit (with or without additive), and chemical stripping combined with scraping.

For each work type, the regime prescribes a specific combination of source extraction, dust shielding, respiratory protection, clothing procedures, showering, and gloves. For the detailed matrices, SEEF refers to the Beheersregime 2.0 document itself, which is publicly available via Rijkswaterstaat. Deviation from the framework is permitted, but only when justified by a certified occupational hygienist, with written reasoning and an equivalent level of protection.

The regime does apply a measured-value threshold for lead: above 0.75% lead in the coating (lowered from 3.75% as of 9 April 2026), the measures in the regime may be insufficient, and additional lead-specific measures are required. For lead, therefore, a preliminary investigation remains relevant within the official regime. For Cr(VI) itself, it does not.

SEEF’s Interpretation Framework: Green, Orange, Red Based on Concentration #

In its own advisory work for clients, SEEF applies an additional interpretation framework based on the Cr(VI) concentration in the material. This framework is separate from the official Beheersregime 2.0; it is a SEEF-specific approach that has proven valuable in practice for clients who want quantitative data for documentation, cost estimation, and communication with contractors. The thresholds are calibrated to the measurable limits of the SEEF method and the typical exposure profiles seen in DP01 samples:

This framework is not required for the official Beheersregime procedure; it is a supplement SEEF applies in its own practice. For clients in infrastructure, real estate, and industry, the combination of a work-type choice (official BR2.0) and a concentration category (SEEF) provides a practical decision model with which a proportionate package of measures can be assembled per project.

Reading Work Type and Concentration Together #

A common misunderstanding is that the green, orange, or red category by itself determines which control measures are needed. That is not the case. The type of work remains the determining factor for the package of measures. An operation such as pneumatic unbolting of chromated bolts on an orange-rated structure requires something different from mechanical sanding over several square meters of orange paintwork. The rough ranking of work types by expected dust emission below helps with that assessment:

• Low: visual inspection, removal of glazing bars without further processing, sweeping (discouraged due to secondary exposure).
• Low to moderate: industrial vacuuming, steam cleaning, manual unbolting, pneumatic unbolting of chromated bolts.
• Moderate: manual sanding, cutting or sawing over a small surface area, drilling.
• Moderate to high: high-pressure water blasting, wet blasting, chemical stripping combined with scraping, mechanical sanding with on-tool extraction.
• High: mechanical sanding without on-tool extraction, sponge blasting, vacuum blasting, laser cleaning, induction cleaning, welding on or near old paint layers.
• Very high: grit blasting (single-use or recyclable), thermal gouging, oxy-fuel cutting, heat application.

For the exact combination of source extraction, respiratory protection, and clothing procedure per work type, SEEF refers to the matrices in the Beheersregime 2.0 document. For situations falling outside the matrices, such as combinations of Cr(VI) with other CMR substances, confined work spaces, or reused structural elements, tailored advice is recommended.

Validation Measurements During Execution #

The preliminary investigation determines the expected risk; validation measurements during the work confirm whether the chosen control measures actually work. This is not a formality. A client who wants to justify the chosen control measures for rollout across a larger area, or an employer who wants to demonstrate that staff remain below the exposure limit, needs factual measurement data for this purpose.

• Personal sampling in the breathing zone, followed by analysis for Cr(VI) in matrix AIR01 (based on NIOSH 7600).
• Stationary measurements at strategic locations to map background concentration and spread.
• For formal assessment against the exposure limit of 1 µg/m³ TWA-8h, SEEF follows NEN-EN 689, with multiple measurements per exposure group.
• A single measurement during a specific task provides a snapshot; useful for indicative validation of a work method, not for formal assessment.
• The filter medium is chosen per situation. NIOSH 7600 prescribes PVC 5.0 µm; a different medium may be used for specific matrices. SEEF advises on this per case.

For a detailed explanation of Cr(VI) air exposure measurements, see the page “Cr(VI) Exposure Measurements.”

Point of Attention Since 9 April 2026: Combination of Cr(VI) and Lead #

The reduction of the Dutch lead exposure limit to 0.03 mg/m³ TWA-8h has direct consequences for work on old paint systems. Lead chromate (PbCrO₄) and lead sulfochromate are the most commonly used Cr(VI) pigments in old red, orange, and yellow layers. A paint layer that tests positive for Cr(VI) therefore statistically also contains lead, and the threshold for lead in a coating above which additional control measures apply has been lowered from 3.75% to 0.75%.

What this means in practice:

• Include lead as standard in the preliminary investigation, even when the main question concerns Cr(VI).
• For positive Cr(VI) results in the orange or red category, always check whether the lead content exceeds the 0.75% threshold; if so, lead-specific measures apply in addition to the Cr(VI) regime.
• For exposure measurements during execution, also analyze for lead on the same filter (depending on the analytical technique chosen).
• Address both substances explicitly in the employer’s risk assessment (RI&E); a combined action plan prevents the need for additional measurements later on.

For the legal background, see the page “Chromium-6 Legislation in the Netherlands.”

Employer Checklist for Planned Paint Work #

The general employer checklist from page A remains the starting point. For planned work on old paint systems, the following steps stand out:

1. Preliminary investigation with representative sampling, quantitative Cr(VI) analysis in DP01, and lead analysis on the same samples.
2. Category determination per surface based on Beheersregime 2.0 (green, orange, red).
3. Determine the work type and choose the corresponding control measures according to the matrix; for situations outside the matrix, obtain tailored advice.
4. PPE selection with justification of protection factor (APF), filter type, and protective clothing (type 5/6 for dusty work).
5. Decontamination and hygiene: clean and dirty zones, washing facilities, and a ban on eating, drinking, and smoking in the work zone.
6. Validation measurement of exposure during execution, in accordance with NEN-EN 689 for recurring work.
7. Registration of exposed employees, type and duration of exposure; retention period of 40 years after the end of exposure per employee.
8. Periodic Medical Examination (PMO) tailored to Cr(VI) and lead exposure.
9. Information and instruction to own personnel and subcontractors, repeated and demonstrable.

How SEEF Supports Employers with Paint Work #

SEEF carries out the entire process: on-site sampling, laboratory analysis using the patented method (WO2023219493), interpretation, and advice. The method is resistant to the known interferences (zinc, iron, copper, aluminum), which makes a practical difference across multiple substrates: for zinc-rich and galvanized steel matrices, this produces substantially higher recoveries compared to the standard reference method (in the practical range of 2–8% zinc, a factor of 3 to 5 above NEN 5617), and on aluminum coatings with strontium chromate primers, the aluminum interference is not accounted for by most standard methods. SEEF carries out paint analysis on all common substrates: steel, cast iron, wood, aluminum, and concrete.

For projects with a fleet-wide or area-wide scope, SEEF helps design the investigation plan, so that a dossier is created that aligns with both Beheersregime 2.0 and the employer’s own risk assessment (RI&E). For specific projects (preliminary investigation ahead of a maintenance campaign, validation measurement during execution, advice for the orange or red category), SEEF can be reached directly via info@seefbv.com or +31 (0)85 047 05 74.

Sources and Legal References #

• Chromium-6 Management Regime, version 2.0, Rijkswaterstaat / ProRail / Rijksvastgoedbedrijf, April 2022. Sector framework for planned maintenance of old steel protective coatings in Dutch infrastructure.
• Working Conditions Decree (Arbeidsomstandighedenbesluit), Chapter 4 (hazardous substances), with additional obligations for CMR substances. Current text: wetten.overheid.nl.
• REACH Regulation (EC) 1907/2006, Annex XIV (authorisation). Cr(VI) substances including chromium trioxide, sodium chromate, potassium dichromate, strontium chromate, and lead chromates. Current list: echa.europa.eu.
• Directive (EU) 2024/869, published 19 March 2024. Amendment of Directive 2004/37/EC (CMRD) and Directive 98/24/EC regarding the exposure limits for lead and diisocyanates. Dutch implementation 9 April 2026.
• Lead exposure limit 0.03 mg/m³ TWA-8h, effective 9 April 2026. Source: SZW list of public exposure limits, Arboportaal, and SER. Lead threshold in coating: from 3.75% to 0.75%.
• Cr(VI) exposure limit 1 µg/m³ TWA-8h, in effect since 2017. Source: SZW list of public exposure limits.
• NEN-EN 689:2018+C1:2019: Assessment of exposure by inhalation to chemical agents.
• NIOSH 7600: Method for hexavalent chromium in air.
• SEEF patented method WO2023219493: selective quantitative analysis of Cr(VI) in complex matrices.

Legislation changes. For formal application, always verify the current text with the source authorities (wetten.overheid.nl, echa.europa.eu, arboportaal.nl).