{"id":"wpc-foundations30-article-018-en","slug":"wpc-fire-performance-loi-cone-calorimetry","locale":"en","url":"https://woodplasticcomposite.net/guides/wpc-fire-performance-loi-cone-calorimetry/","title":"WPC fire behaviour: LOI, cone calorimetry and flame retardants","answer":"A flame-retardant additive can change burning behaviour, but product fire performance must be established using the relevant test and end-use construction.","author":"NFC & WPC Knowledge Reference","faqIds":[],"tagIds":[],"noindex":false,"related":["wpc-foundations30-article-009-en","wpc-foundations30-article-010-en","wpc-foundations30-article-011-en"],"version":1,"modified":"2026-10-16","reviewer":"","sections":[{"id":"know-what-the-measurements-describe","text":"Limiting oxygen index, or LOI, concerns the oxygen concentration needed to sustain burning under a specified procedure. Cone calorimetry can measure heat release under an imposed heat flux; peak heat-release rate is one result. Neither measurement is interchangeable with a building-product classification. [R19,R44]\n\nResearch has investigated ammonium polyphosphate, phosphorus/nitrogen systems, melamine-related additives and biochar-containing formulations. Their effects depend on the complete composition. A study of modified bamboo biochar in PLA reported burning-test improvements for its tested specimens. It does not qualify an unrelated WPC cladding system.","heading":"Know what the measurements describe","references":[2],"url":"https://woodplasticcomposite.net/guides/wpc-fire-performance-loi-cone-calorimetry/#know-what-the-measurements-describe"},{"id":"compare-systems-rather-than-additive-names","text":"Another investigation combined a bio-based TPU, rice husk and ammonium polyphosphate. This is a different matrix and formulation from conventional PE decking. Results should remain attached to that distinction.","heading":"Compare systems rather than additive names","references":[3],"url":"https://woodplasticcomposite.net/guides/wpc-fire-performance-loi-cone-calorimetry/#compare-systems-rather-than-additive-names"},{"id":"questions-for-a-fa-ade-enquiry","text":"Ask which product, thickness, surface and installation build-up were tested. Request the classification document and its field of application. Verify that the proposed backing, cavity, insulation and fixing arrangement fall within the documented use.\n\nFor an experimental formulation, evaluate conditioned properties and processing behaviour alongside burning results. A laboratory improvement is useful development evidence, but procurement needs the completed product and installation evidence.\n\nAvoid the word fireproof for ordinary wood–polymer composites. A precise fire-performance description is more useful to an architect and more defensible than an absolute promotional label.","heading":"Questions for a façade enquiry","references":[],"url":"https://woodplasticcomposite.net/guides/wpc-fire-performance-loi-cone-calorimetry/#questions-for-a-fa-ade-enquiry"},{"id":"evidence-scope","text":"[1] Experimental study; publisher abstract/search extract consulted.\n\n[2] Experimental study; laboratory burning behaviour.\n\n[3] Experimental study; TPU system.","heading":"Evidence and source scope","references":[1,2,3],"url":"https://woodplasticcomposite.net/guides/wpc-fire-performance-loi-cone-calorimetry/#evidence-scope"}],"seoTitle":"WPC fire behaviour: LOI, cone calorimetry and flame retardants","topicIds":[],"published":"2026-10-16","tableText":"","takeaways":"","aiAssisted":true,"categoryId":"wpc-foundations30-category-interface-additives","reviewedAt":"","change_note":"Converted from the referenced English foundations collection. General technical information and editorial specification guidance; not product certification.","description":"Understand WPC fire-test terminology, including LOI and peak heat-release rate, and why additives or laboratory results do not establish a façade classification.","heroImageId":"","referenceIds":["wpc-foundations30-ref-r19","wpc-foundations30-ref-r44","wpc-foundations30-ref-r45"],"review_status":"AI-assisted English article. Human technical review has not been recorded.","table_caption":"","seoDescription":"Understand WPC fire-test terminology, including LOI and peak heat-release rate, and why additives or laboratory results do not establish a façade classification.","translationGroup":"wpc-foundations30-018-2026","references":[{"url":"https://www.mdpi.com/2073-4360/15/8/1827","type":"web","title":"Mechanical, Thermal, and Fire Retardant Properties of Rice Husk Biochar Reinforced Recycled High-Density Polyethylene Composite Material (2023)","noindex":false,"accessed":"2026-10-15","seoTitle":"Mechanical, Thermal, and Fire Retardant Properties of Rice Husk Biochar Reinforced Recycled High-Density Polyethylene Composite Material (2023)","publisher":"www.mdpi.com","description":"Experimental study; publisher abstract/search extract consulted","seoDescription":"Experimental study; publisher abstract/search extract consulted"},{"url":"https://www.mdpi.com/2073-4360/15/2/360","type":"web","title":"Fabrication of Phytic Acid/Urea Co-Modified Bamboo Biochar and Its Application as Green Flame Retardant for Polylactic Acid Resins","noindex":false,"accessed":"2026-10-15","seoTitle":"Fabrication of Phytic Acid/Urea Co-Modified Bamboo Biochar and Its Application as Green Flame Retardant for Polylactic Acid Resins","publisher":"www.mdpi.com","description":"Experimental study; laboratory burning behaviour","seoDescription":"Experimental study; laboratory burning behaviour"},{"url":"https://www.mdpi.com/2075-5309/15/18/3420","type":"web","title":"Eco-Friendly Flame-Retardant Construction Composites Based on Bio-Based TPU, Recycled Rice Husk, and Ammonium Polyphosphate","noindex":false,"accessed":"2026-10-15","seoTitle":"Eco-Friendly Flame-Retardant Construction Composites Based on Bio-Based TPU, Recycled Rice Husk, and Ammonium Polyphosphate","publisher":"www.mdpi.com","description":"Experimental study; TPU system","seoDescription":"Experimental study; TPU system"}],"faqs":[]}