⚠️ Asbestos in building materials

Environmental ISO 22262-1

Overview

Asbestos is a group of natural silicate minerals with a fibrous structure, widely used in construction until the 1990s due to excellent thermal insulation, fire-resistant and mechanical properties. The most common varieties include: chrysotile (white asbestos, ~95% of global use), amosite (brown asbestos) and crocidolite (blue asbestos). Inhalation of asbestos fibers causes asbestosis, lung cancer and mesothelioma — diseases with many years of latency.

Identification of asbestos in building materials is crucial when planning renovations, demolitions and thermal modernization of buildings. Polish law (Journal of Laws 2004 No. 71, item 649) imposes the obligation to inventory asbestos-containing products and safely remove them by 2032. Every property owner with asbestos materials must have a technical condition assessment and removal plan.

The PLM (Polarized Light Microscopy) method is the basic technique for identifying asbestos fibers in bulk samples — it enables differentiation of individual varieties based on optical properties (birefringence, extinction angle, elongation signs). This is complemented by SEM-EDS (Scanning Electron Microscopy with Energy Dispersive Spectroscopy), which allows chemical identification of fibers and detection of thin fibers invisible in PLM (below 0.2 µm).

Laboratories performing these tests require specialized personnel training and accreditation. Samples must be collected by qualified samplers while following procedures that minimize dusting and fiber exposure.

THE LIMIT VALUE FOR ASBESTOS — THREE LAYERS OF THE PROVISION, AND THE TABLE ALONE IS NOT ENOUGH (act read on 23.09.2026). The list of maximum admissible concentrations as worded by the regulation of 26 March 2026 (Journal of Laws 2026 item 447) lists asbestos under **item 32**, as "Azbest (jeden lub więcej rodzajów azbestu wymienionych poniżej) – włókna respirabilne" [Asbestos (one or more types of asbestos listed below) – respirable fibres], with references to footnotes 11) and 12) and with an enumeration of six varieties (actinolite, anthophyllite, chrysotile, amosite, crocidolite, tremolite). And this is where the layers begin that cannot be seen if one reads the table alone.

LAYER ONE — A CELL WITH TWO VALUES. In column 9 of the list — the NDS expressed as the number of fibres per cm³ — there stands "0.01 or 0.002". This is neither a range nor a typesetting error: footnote 12) settles that ONE of these values applies, depending on how wide the fibres counted by the laboratory are. With the value 0.002, fibres with a width from 0.2 to 3 µm are counted; with the value 0.01, fibres narrower than 0.2 µm are ALSO taken into account. The admissible value is therefore coupled to the counting technique, not independent of it — a laboratory that cannot see fibres below 0.2 µm cannot apply the higher threshold (0.01).

LAYER TWO — THE DEFINITION OF A FIBRE. Footnote 11) states what counts as a respirable fibre in the first place: length above 5 µm, width below 3 µm and a length-to-width ratio of not less than 3:1. An object that does not meet these three conditions does not enter the result, even if it is asbestos.

LAYER THREE — A TRANSITIONAL PROVISION THAT IS NOT IN THE ANNEX. § 2(6) of the amending regulation provides: "Until 20 December 2029, the NDS [maximum admissible concentration] value for asbestos is 0.01 fibres per cm3". Until that date the choice from the table is therefore illusory — the higher value applies, regardless of how precisely the laboratory counts. Whoever reads the table alone will today give two values to choose from; whoever reads the paragraphs will give one.

WHY THIS STANDS HERE. This entry describes the determination of asbestos in materials and in air, and the result of such a determination is compared precisely with this value. In the whole list, asbestos is the best example of the fact that with a figure from the annex one must also read the paragraphs of the amending regulation: in this one row there occur at once a cell with two values, a footnote linking the value to the method, and a transitional provision reaching to the year 2029.

Method principle

Polarized light microscopy (PLM) utilizes the birefringence phenomenon — light passing through asbestos fibers splits into two rays with different propagation velocities. The analyst identifies the type of asbestos based on a set of optical properties: refractive indices, interference colors, extinction angle, elongation sign and dispersion. The sample is prepared in immersion liquids with known refractive indices. SEM-EDS completes the identification — an electron beam excites the emission of X-rays characteristic of elements in the sample, giving a spectrum of chemical composition (Si, Mg, Fe, Na, Ca) that unambiguously identifies the asbestos variety.

Applications

• Inventory of asbestos materials in buildings (statutory obligation)
• Technical condition assessment of asbestos-containing products
• Inspection before demolition and renovation of buildings
• Workplace monitoring during asbestos removal
• Testing of asbestos-cement sheets, thermal insulation and seals
• Expert opinions for property managers and building inspectors
• Control of asbestos waste before disposal

Key parameters

Standard

Standard number

ISO 22262-1:2012 — norma MIĘDZYNARODOWA, nie wprowadzona do zbioru PN

Title (PL)

Próbki powietrza i materiałów budowlanych — Oznaczanie zawartości azbestu — Część 1: Mikroskopia polaryzacyjna i SEM-EDS

Title (EN)

Air quality and building materials — Determination of asbestos content — Part 1: Polarized light microscopy and SEM-EDS

Step-by-step procedure

1. Sample acceptance and registration

   Accept sample (min. 5–10 g) in sealed PE bag with location label. Register in LIMS. Do not open outside fume hood!

   ⏱ Time: 5 min

2. Macroscopic examination

   In HEPA-filtered fume hood perform visual examination of sample — assess color, texture, presence of layers and visible fibers.

   ⏱ Time: 5–10 min

3. Sample preparation

   Crush sample with ceramic tools. Separate fibrous fractions. Prepare min. 2 slides in immersion liquids with different nD.

   ⏱ Time: 15–20 min

4. PLM analysis — parallel nicols

   Observe slide at 100×–400× magnification. Assess fiber morphology (shape, thickness, elasticity), color, pleochroism.

   ⏱ Time: 10–15 min

5. PLM analysis — crossed nicols

   Switch on analyzer. Assess birefringence, interference colors, extinction angle. Use compensator to determine elongation sign.

   ⏱ Time: 10–15 min

6. Dispersion staining identification

   Using dispersion staining method with appropriate RI liquid confirm fiber type based on characteristic colors.

   ⏱ Time: 10 min

7. SEM-EDS analysis (optional)

   Sample on carbon tape coated with Au/Pd layer. SE/BSE imaging + EDS point analysis for chemical identification of fibers.

   ⏱ Time: 1–3 h

8. Content estimation

   Estimate percentage asbestos content by visual comparison with standards or point counting analysis (EPA 600 point counting).

   ⏱ Time: 15 min

9. Documentation and report

   Take microphotographs of identified fibers. Prepare report with results: asbestos type, estimated content, method.

   ⏱ Time: 15–20 min

10. Waste disposal

    Collect all waste (slides, disposable tools, filters) in marked asbestos waste containers. Disposal according to ADR.

    ⏱ Time: 10 min

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Asbestos — carcinogenic substance cat. 1A! Work only in fume hood with HEPA H14 filtration
• Mandatory: FFP3 mask, nitrile gloves, disposable Tyvek suit, safety goggles
• No eating, drinking or smoking in laboratory room
• Employee exposure monitoring — fiber concentration measurement in air (PN-EN ISO 16000-7)
• Asbestos waste — disposal by authorized receiver, ADR transport class 9
• Specialized OSH training for workers in contact with asbestos (Journal of Laws 2010 No. 162, item 1089)

Frequently asked questions