{"id":2545,"date":"2026-02-05T03:55:05","date_gmt":"2026-02-05T03:55:05","guid":{"rendered":"https:\/\/hexatrontech.com\/ir\/?p=2545"},"modified":"2026-02-06T02:45:00","modified_gmt":"2026-02-06T02:45:00","slug":"tpa-ratings-in-ugr19-prismatics","status":"publish","type":"post","link":"https:\/\/hexatrontech.com\/ir\/blog\/2026\/02\/tpa-ratings-in-ugr19-prismatics\/05\/","title":{"rendered":"Safety First: TP(a) Fire Ratings in UGR<19 Prismatics Diffusers"},"content":{"rendered":"\n

When selecting lighting for commercial spaces, offices, or educational facilities, achieving a low Unified Glare Rating (UGR<19) is often the top priority for visual comfort. However, there is a critical safety specification that often sits in the fine print but carries equal weight: Fire Safety Regulations.<\/strong> <\/p>\n\n\n\n

For lighting manufacturers, understanding the difference between Polycarbonate (PC) and Polystyrene (PS) materials and how they achieve TP(a) classification is essential for compliance with building codes.<\/p>\n\n\n\n

In this post, we break down the fire rating performance of two key prismatic materials based on recent laboratory tests.<\/p>\n\n\n\n


What is TP(a) Classification?<\/strong><\/h2>\n\n\n\n

Under the Building Regulations 2010, Approved Document B (Fire Safety)<\/strong>, lighting diffusers are classified based on their burning behavior.<\/p>\n\n\n\n

TP(a) Rigid<\/strong> is the highest classification for thermoplastic lighting diffusers. To achieve this, a material must demonstrate that:<\/p>\n\n\n\n

\n
\n

1. The test flame extinguishes before reaching the first mark (25mm) during testing.<\/p>\n\n\n\n

2. Alternatively, the duration of flaming or afterglow does not exceed 5 seconds following the removal of the burner.<\/p>\n<\/div>

\"TPA-V0<\/figure><\/div>\n<\/div><\/div>\n\n\n\n

We recently commissioned independent testing by SGS to see exactly how our Prismatic Diffusers perform under these rigorous conditions. Here is how both materials stood up to the heat.<\/p>\n\n\n\n

\n
\"Honeycomb<\/figure>
\n

<\/p>\n\n\n\n

Test Standard:<\/strong> BS 2782-0:2011 Method 508A.<\/p>\n\n\n\n

Official Classification:<\/strong> TP(a) rigid.<\/p>\n\n\n\n

<\/p>\n<\/div><\/div>\n<\/div><\/div>\n\n\n\n

<\/p>\n\n\n\n

\\We offer 2 materials TP(a) rated: Polystyrene in special grade, and the regular Polycarbonate.<\/p>\n\n\n\n


Polystyrene (PS) <\/strong><\/h3>\n\n\n\n
\n
\n

Polystyrene is often chosen for its cost-effectiveness and excellent optical clarity. Historically, PS struggled with fire ratings compared to PC, but advanced formulations now allow high-quality PS prismatics to achieve the required safety standards.<\/p>\n\n\n\n

The Results:<\/strong> The PS samples performed flawlessly against the TP(a) criteria. Similar to the PC version, the flame front did not<\/strong> pass the 25mm mark.<\/p>\n<\/div>

\"\"<\/figure><\/div>\n<\/div><\/div>\n\n\n\n


Polycarbonate (PC) <\/strong><\/h3>\n\n\n\n
\n
\n

Polycarbonate is renowned for its impact resistance and thermal stability. Our recent testing confirms its robust safety profile for lighting applications.<\/p>\n\n\n\n

The Results:<\/strong> During the test, the PC specimens showed exceptional resistance. The flame did not<\/strong> travel to the 25mm mark, and critically, there was 0 seconds<\/strong> of afterflame or afterglow once the burner was removed.<\/p>\n<\/div>

\"\"<\/figure><\/div>\n\n\n\n

<\/p>\n<\/div><\/div>\n\n\n\n


Final Thoughts<\/strong><\/h2>\n\n\n\n

Achieving a UGR<19 glare rating shouldn’t come at the expense of safety. Whether your project requires the mechanical strength of Polycarbonate or the specific optical properties of Polystyrene, both the Poly Series<\/strong> and S Series<\/strong> are verified to meet the TP(a)<\/strong> fire safety classification.<\/p>\n\n\n\n

Using the TP(a) formula we can custom produce in various other types:<\/p>\n\n\n\n

    \n
  • Other types of prisms (Hexagonal, Micro Hexagon, etc)<\/li>\n<\/ul>\n\n\n\n
      \n
    • Other transmittance levels (From 50% to clear)<\/li>\n<\/ul>\n\n\n\n

      This means you can specify either material with confidence, knowing they comply with the stringent requirements of Building Regulations.<\/p>\n","protected":false},"excerpt":{"rendered":"

      When selecting lighting for commercial spaces, offices, or educational facilities, achieving a low Unified Glare Rating (UGR<19) is often the top priority for visual comfort. However, there is a critical safety specification that often sits in the fine print but carries equal weight: Fire Safety Regulations. For lighting manufacturers, understanding the difference between Polycarbonate (PC) and […]<\/p>\n","protected":false},"author":1,"featured_media":456,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[129],"tags":[],"class_list":["post-2545","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized-en"],"acf":[],"_links":{"self":[{"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/posts\/2545","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/comments?post=2545"}],"version-history":[{"count":0,"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/posts\/2545\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/media\/456"}],"wp:attachment":[{"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/media?parent=2545"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/categories?post=2545"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hexatrontech.com\/ir\/wp-json\/wp\/v2\/tags?post=2545"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}