CN subheading 6806 20 of the Combined Nomenclature covers exfoliated (expanded) vermiculite, expanded clays, foamed slag and similar expanded mineral materials, including intermixtures thereof. Exfoliated vermiculite is produced by rapidly heating raw vermiculite ore to temperatures above 800 degrees Celsius, causing the mineral to expand up to eighteen times its original volume. The resulting lightweight, low-density granules possess excellent thermal insulation and fire-resistance properties, with maximum service temperatures typically exceeding 1000 degrees Celsius. Expanded clays, commercially known as LECA (Lightweight Expanded Clay Aggregate) or similar trade names, are produced by firing suitable clay minerals in rotary kilns at approximately 1100 degrees Celsius, producing a porous, rounded aggregate widely used in construction, horticulture and water filtration. Foamed slag is a by-product of blast-furnace iron production, formed by foaming molten slag during granulation. All products covered by this subheading share characteristically low bulk density and low thermal conductivity. Classification under 6806 20 is based on the General Interpretive Rules (GIR) of the CN, specifically rules 1 and 6, together with the Notes to Chapter 68. The subheading is distinguished from 6806 10 (mineral wools in bulk, sheets or rolls) and 6806 90 (mixtures and finished articles of mineral insulating materials) by the nature of the thermal expansion process and the absence of additional binding agents that would form a finished shaped article.

The import of goods classified under CN 6806 20 into the European Union is governed by the Union Customs Code (Regulation (EU) No 952/2013). Standard import documentation includes a customs declaration with the correct CN and TARIC codes, a commercial invoice, a transport document, and a technical specification or material datasheet indicating the type of mineral material and production process. An EORI number is mandatory for the importer. To benefit from preferential duty rates, an appropriate proof of origin is required: EUR.1 movement certificate, invoice declaration, or REX (Registered Exporter System) statement. Where vermiculite or expanded clay is imported as waste or recycled material, a waste shipment authorisation may be required under Regulation (EC) No 1013/2006. Products placed on the EU market as construction products covered by harmonised European standards (e.g. EN 13055 for lightweight aggregates for concrete, mortar and grout) are subject to Regulation (EU) No 305/2011 (Construction Products Regulation, CPR) and require a Declaration of Performance (DoP) and CE marking. The CPR applies when the product is within the scope of a harmonised standard and marketed as a construction product. Duty rates for CN 6806 20 should be verified in the TARIC database of the European Commission, taking into account the country of origin.

Exfoliated vermiculite classified under CN 6806 20 is used in construction as a loose-fill insulation for loft spaces, cavity walls and underfloor voids, as a component in fire-resistant boards and enclosures in industry, and as a growing medium amendment in horticulture. Expanded clay aggregate is used as lightweight aggregate in concrete mixes, as thermal and drainage insulation in green roofs and landscaping, as a biological filter medium in wastewater treatment, and as lightweight void fill under floors. The key classification boundary lies between 6806 20 (loose granulates or bulk materials without additional binders forming a shaped article) and 6806 90 (finished articles such as boards, blocks, pipe sections shaped from mixtures containing mineral binders). Loose granulates remain in 6806 20 regardless of packaging (bags, big-bags, bulk), while pressed or cemented shaped articles fall into 6806 90. Each classification decision requires an assessment of the physical state and composition of the goods. Where doubt exists, it is advisable to apply for a Binding Tariff Information (BTI) decision from the competent customs authority. BTI decisions are binding throughout the EU for three years from the date of issue and provide legal certainty for importers. Existing BTI decisions can be searched in the EBTI database maintained by the European Commission.

Exfoliated vermiculite and expanded clays under CN 6806 20 carry a 1.7% EU duty. Used as insulation material and lightweight aggregate.