CPR Cable Selector
Check a cable against the BS 7671 requirement or your specification, find what is required at a location, and verify its Construction Products Regulation (CPR) Euroclass on the Declaration of Performance (DoP). Every library row shows the source of its class.
Free to run in the tool. The Engineering Toolkit subscription adds the full cable library, the printed report, the editable Excel, Word, comma-separated values (CSV) and text exports, plus your projects saved for editing later.
Data basis & scope
Guidance only. The manufacturer Declaration of Performance, the project specification and the designer's judgement take precedence. Verify every Euroclass on the current DoP.
- 26cables in the library, each linked to its source
- 14cables verified from a Declaration of Performance the manufacturer still lists
- 32,650scenarios pass in each tier on 2.5.5, including all 36 corridor answers
- Weeklyevery evidence link re-checked and flagged if it stops resolving
- Last reviewed
- September 2026
- Data basis
Show the full record
Of the 26 library cables, 14 have their class read from a Declaration of Performance (DoP) the manufacturer still lists, 6181B from a DoP that Doncaster no longer lists (checked 30/09/2026), 5 from manufacturer datasheets hosted with the tool, and 6 are marked DoP required
- Validated against
Show the full record
30/09/2026 (2.5.5): 6181B, whose Declaration of Performance (DoP) Doncaster no longer lists, is labelled "DoP no longer listed" in the Toolkit Cable library and on Check a cable; the footer names that DoP after the weekly link check. Where Approved Document B is quoted, and in the non-residential corridor's Advisory class line, its edition is named. Printed reports have no blank last page; every page is numbered. No verdict or filled-in class changed from 2.5.4 in 18,172 cases per tier. A new automated check and 32,650 scenarios per tier pass; the served files matched the release and the page was read. 30/09/2026 (2.5.4): The free library count shows as verified only the 14 cables whose Declaration of Performance the manufacturer still lists, and names 6181B, whose declaration Doncaster no longer lists. In the tool, reports and exports, the Advisory class line for a non-residential common corridor names only Approved Document B (current edition) as setting no reaction-to-fire class for cables. The 2.5.3 changelog entry is shortened. No verdict or filled-in class changed from 2.5.3 in 18,172 cases per tier. A new automated check (failing on 2.5.3) and 10,314 scenarios per tier pass; the served files matched the release and the page was read. 30/09/2026 (2.5.3): BS 7671 Appendix 2 Item 17 is cited instead of Building Regulations reg 7(3)(d). Indoors, the Fca Caution line no longer says “use containment” and cites BS 7671 527.1.4. Two unsourced statements are replaced by BS 7671 527.1.3 and Institution of Engineering and Technology Guidance Note 1, 10th Edition, 5.5. Doncaster’s Declarations of Performance were re-read: 6491B now shows Dca-s1,d2,a1; 6181B still shows Eca; its declaration is no longer listed. No verdict changed. Two new automated checks pass on 2.5.3 and fail on 2.5.2; 10,314 scenarios per tier pass; the served files matched the release and the page was read. 30/09/2026 (2.5.2): A residential common corridor is Compliant only where you confirm, in three new questions, fire-resisting enclosure or all four criteria of BS 9991:2024 27.2.2, and that it is not a protected escape route. At protected escape routes, s2, s3 and no smoke grade read Caution on smoke. The Understand tables match BS EN 13501-6:2018+A1:2022. A new automated check of these verdicts fails on 2.5.1; another prints 14 cases and finds every line in them at 7 pt or more; the 10,314 scenarios per tier and named checks were re-run; the served files matched the release and the page was read. 26/09/2026 (2.5.1): in the tool, the report and the exports, the check lines, notes and table rows that were revised in this release now use "shall" where they state what BS 7671 Regulations 422.2.1 and 560.8.1 require, and "should" where they state what BS 9991:2024 27.2.2 recommends, to match the wording of each clause. In the report, the requirement row for a residential common corridor no longer states that the BS 7671 flame test is relaxed in metal tray or metal conduit, and the requirement row for a fire-survival circuit now lists the wiring systems in Regulation 560.8.1, including a wiring system maintaining the necessary fire and mechanical protection. The check line for smoke class s2 or s3 no longer names s1 as the 60% grade: it names s1a and s1b as the grades with a light transmittance figure. Where one of these lines states a position that goes beyond the standard, such as taking Cca as the class that evidences the BS EN 60332-3 flame test for an open run, that position is now stated in a separate sentence as the position taken in this tool. The green for a pass, the amber for a point to check or a warning, and the grey for a neutral mark are now darker, so that any white text on them meets the 4.5:1 contrast that the Web Content Accessibility Guidelines 2.2 require at level AA for text of 12 px; this change applies only to the colours, not to any calculation, result, wording or layout. The classes, tests, checks and verdicts and the cables in the library are unchanged. The review that found these lines ran on 2.5.0: every line shown in the tool and in the report was read against the text of BS 7671:2018+A4:2026 Regulations 422.2.1 and 560.8.1 and Appendix 2 Item 17, and of BS 9991:2024 27.2.2, read word for word. Every control in both tiers of 2.5.1 was click tested at desktop width and at 375 px phone width (42 checks in the paid tier and 38 in the free tier, each at both widths). The 9,590 scenarios in each tier and the 39 named checks were re-run on 2.5.1 with no findings. A new automated check reads the wording of every line that cites these clauses, in the tool, the report and the exports; it fails on the 2.5.0 build and passes on 2.5.1; the served files matched the release and the page was read. 26/09/2026 (2.5.0): the tool now looks like the PD Power Distribution tool, with the same font and colours, and the same style of tabs, buttons, fields, tables, check lines and tags. The tool name and version are shown in a new dark bar at the top of the tool, with the four tabs directly under it, and the version now matches the release. When the page is under 768 px wide, as on a phone, or is viewed on a touch screen, the text in the tool's fields is 16 px, so a phone does not zoom the page when a field is tapped. The printed report is in the new colours, and apart from the version number, its text, layout, font, font sizes and page breaks are unchanged. The panel for saving and exporting, below the results, keeps its present colours for now. The classes, tests, checks and verdicts, the wording of every check line and note, the cables in the library and their sources, the report emailed to free users, the exports and the saved reports are unchanged. A new automated check prints the report to PDF with the 2.4.2 style and with the 2.5.0 style for eight cases across the four tabs, and the page count and the text on every page are the same with both; the check fails when the text of the library table is enlarged. A new check of the look in a browser, at desktop width and at 375 px phone width, passes with the 2.5.0 style and fails with the 2.4.2 style. The 9,590 scenarios in each tier, the 39 named checks and the automated check of every BS 5266-1:2025 citation were re-run on 2.5.0 with no findings; the served files matched the release and the page was read. 16/09/2026 (2.4.2): the Engineering Toolkit line now reads Free to run in the tool. The classes, the checks, the report and the exports are unchanged. The 9,590 scenarios in each tier and the 39 named checks were re-run on 2.4.2 with no findings; verified live after upload. 15/09/2026 (2.4.1): the emergency lighting note on the fire-survival circuit was read back against BS 5266-1:2025, which replaced the 2016 edition: supply cables to self-contained luminaires need not be fire-protected (8.1), and the wiring from a central power supply system should resist fire and retain circuit integrity (8.2.1), using one of the cables listed in 8.2.2. The smoke grade and flame class lines were revised in plain UK English. A new automated check reads every BS 5266-1 citation and the wording of every program file on both tabs, and fails on the 2.4.0 build; the 9,590 scenarios in each tier and the 39 named checks were re-run on 2.4.1 with no findings; no class, test or verdict changed; verified live after upload. 10/09/2026 (2.4.0): a check across every PD tool for a question asked of every user that only changed a badge or led to a redirect. Outdoors or underground the containment question was found to change only the badge, Compliant or Caution, while the substantive finding was the same either way, because the reaction-to-fire class outdoors is whatever the project specification states; the question is removed and the check prints that finding as one Caution line. On the Check a cable tab the corridor building type was found to lead, for a non-residential building, to a redirect rather than a result, since Approved Document B and BS 9999 set no cable class for wiring; the question is removed from that tab, the corridor is checked as the residential BS 9991 27.2.2 case and the non-residential position is stated as a line on every corridor result, with a corridor that is a protected escape route pointed to the BS 7671 422.2 location. The What do I need tab keeps both building types, where the requirement table differs. The enumeration was re-run on 2.4.0, 9,590 scenarios in each tier over the locations the tab now offers, with no findings; the automated tests gained checks that no building type and no outdoor containment question is asked on the check tab, that the corridor result shows the non-residential line and that an outdoor result is never Compliant on the class alone; the same tests fail on the 2.3.1 build. No class, test or clause changed; verified live after upload. 04/09/2026: the full input range was enumerated, 11,684 scenarios in each tier: every combination of flame, smoke, droplet and acidity grade, valid and invalid, against every location, building type, containment setting, specification preset and typed required class, plus every library cable against every location. Each verdict was compared with an independent reading of Regulation 422.2.1, its Note 1 and BS 9991 27.2.2, invalid codes were confirmed to receive no verdict, a better grade was confirmed never to receive a worse verdict, and a cable without a Declaration of Performance on file was confirmed to be asked for it. One finding: against a required class from a specification that asks for s2 or s3, a bare s1 printed Caution with the 422.2.1 transmittance note, where the EN 13501-6 scale places s1 above both. It was fixed in 2.3.1: in the class comparison a bare s1 reads Caution only against a required s1a or s1b, which state the light transmittance figure it lacks; the escape route locations under Regulation 422.2.1 are unchanged. The enumeration was re-run on 2.3.1 in both tiers with no findings, and the same tests fail on the 2.3.0 build. Verified live after upload. 03/09/2026 (2.3.0): every check line was audited against BS 7671:2018+A4:2026 Regulation 422.2.1 and its Note 1, read word for word. A bare s1 was found to be passed as meeting the 60% light transmittance the regulation names: s1 has no transmittance figure, the s1a and s1b grades do, so it now reads Caution and asks for the figure on the DoP. Acidity a1, which is the BS EN 60754-2 grade, was passed against the BS EN 60754-1 limit of 0.5%; it now reads Caution and asks for that figure. The fire-survival location said the CPR class still applied, where Note 1 places no CPR requirement on 560.8 fire-resisting cables; both tabs now state the Note 1 position. A common corridor was passed for any class run open; it now asks whether the cable is in metal conduit, trunking or tray and asks the building type, residential to BS 9991:2024 27.2.2 and other buildings to Approved Document B and BS 9999. A typed class is checked against the EN 13501-6 class format before any verdict, the verified source line prints only for the class the DoP declares, and the blank cable option clears the class box. The emailed and PDF report now include the findings table. The audit checks were run in both tiers; verified live after upload. 02/09/2026 (2.2.1): the revised wording was checked in the tool against the house style; no class, test or verdict changed. Every Euroclass in the tool is read from the manufacturer's own Declaration of Performance or a hosted datasheet, and each row links to that evidence: of 26 cables, 15 are verified from a Declaration of Performance, 5 have a manufacturer datasheet hosted with the tool, and 6 are marked DoP required because the maker publishes neither. Every one of those links is re-checked weekly and flagged when it stops resolving. The framing was verified against the sources in June 2026: UK law sets no minimum Euroclass for internal wiring (BS 7671 Appendix 2 Item 17, and Building Regulations regulation 7(3)(d) exempts electrical installations, while regulation 7(2) mandates a class only for external walls), so selection is by the BS 7671 component tests, flame propagation to BS EN 60332-1-2, smoke to BS EN 61034-2 and acid gas to BS EN 60754-1 added by A4:2026, with the Euroclass as the verification layer. Each specification preset states its own standards basis, BS 7671 422.2.1 for escape routes open and in containment and BS 9991 27.2.2 for surface wiring. No class in the library is inferred from a datasheet description or from a comparable product.
- Specifies and validates a cable's reaction to fire class under the Construction Products Regulation: the Euroclass, from Aca to Fca, and its smoke, flaming droplet and acidity ratings, read from the manufacturer's Declaration of Performance rather than inferred from a datasheet.
- It classifies the cable, not the installation. The Euroclass is one input to the fire strategy, the escape route and cable requirements of BS 7671 Section 422, and any BS 8519 life safety duty, which you assess separately. A declared class is only as current as the Declaration of Performance behind it, so confirm the DoP for the exact product and issue before you specify. The designer remains responsible for the final specification.
What's changed
- September 2026 · v2.5.56181B, whose Declaration of Performance (DoP) Doncaster no longer lists, is labelled "DoP no longer listed" in the Toolkit Cable library and on Check a cable. Where Approved Document B is quoted, and in the non-residential corridor’s Advisory class line, its edition is named. Printed reports no longer end with a blank page; every page is numbered. No verdict changed.
- September 2026 · v2.5.4The free library count shows as verified only the 14 cables whose Declaration of Performance the manufacturer still lists, and names 6181B, whose declaration Doncaster no longer lists. In the tool, reports and exports, the Advisory class line for a non-residential common corridor names only Approved Document B (current edition) as setting no reaction-to-fire class for cables. No verdict changed.
- September 2026 · v2.5.3BS 7671 Appendix 2 Item 17 is cited instead of Building Regulations reg 7(3)(d). In general areas, two unsourced statements are replaced by BS 7671 527.1.3 and Institution of Engineering and Technology Guidance Note 1, 10th Edition, 5.5. Doncaster’s Declarations of Performance were re-read: 6491B now shows Dca-s1,d2,a1. The wording changed in the tool, reports and exports; no verdict changed.
- September 2026 · v2.5.2A residential common corridor is now Compliant only where you confirm, in three new questions, fire-resisting enclosure or all four criteria of BS 9991:2024 27.2.2, and that it is not a protected escape route; if it is, BS 7671 422.2.1 applies. At protected escape routes, s2, s3 and no smoke grade read Caution on smoke. No other verdict changed.
- September 2026 · v2.5.1Some check lines, notes and table rows now read shall or should, as the clause they cite does. The report no longer states that the BS 7671 flame test is relaxed in metal tray or metal conduit in a residential common corridor. The green, amber and grey are now darker, for a contrast above 4.5:1 with white text (Web Content Accessibility Guidelines 2.2, level AA). The classes and verdicts are unchanged.
- September 2026 · v2.5.0The tool now looks like the PD Power Distribution tool, with the same font and colours. The tool name and version are in a new dark bar at the top, with the four tabs under it. The printed report is in the new colours. The classes, the verdicts, the wording of every check line and the exports are unchanged.
- September 2026 · v2.4.2The Engineering Toolkit line now reads Free to run in the tool. The classes, the checks, the report and the exports are unchanged
- September 2026 · v2.4.1The emergency lighting note on the fire-survival circuit now cites BS 5266-1:2025: supply cables to self-contained emergency luminaires need not be fire-protected (8.1), and the wiring from a central power supply system to its luminaires should resist fire and retain circuit integrity (8.2.1). No class, test or verdict changed.
- September 2026 · v2.4.0On the Check a cable tab, the containment question is no longer asked for an outdoor or underground run: the class is whatever the project specification states, shown as a Caution line. For a corridor on that tab, the building type is no longer asked: the residential BS 9991 27.2.2 case is checked and the non-residential position is stated. The What do I need tab still has both building types. No class, test or clause changed.
- September 2026 · v2.3.1Against a required class from a specification, a bare s1 is now compared on the EN 13501-6 scale like any other smoke grade. It meets a required s1, s2 or s3, and still reads Caution against a required s1a or s1b, which include the light transmittance figure it lacks. The escape route locations under Regulation 422.2.1 are unchanged.
- September 2026 · v2.3.0A bare s1 now reads Caution because it has no light transmittance figure, and acidity a1 reads Caution with a request for the BS EN 60754-1 figure on the Declaration of Performance. The corridor and the external run are Compliant only in metal conduit, trunking or tray. The check lines were corrected against BS 7671:2018+A4:2026.
- September 2026 · v2.2.1The wording in the tool and in the report was revised in plain UK English: standards require and apply, the report names the applicable standard, plurals written out, no dashes in the on-screen text. No verdict or class changed
- August 2026 · v2.2.0Fix: the exported and emailed report was missing its body. The cable, what it was checked against, the applicable reference and the verdict are now included in the report, so the emailed summary, the printed report and the editable Excel, Word, CSV and text exports all state the check in full alongside the findings table
- August 2026 · v2.1.0Free use is now measured in sessions: after three days of anonymous use, you enter your email address to continue free use, with no password and no account. The compiled cable library is now part of the Engineering Toolkit, with a three-row sample kept free, and every verified class is still filled in automatically in the checker.
- August 2026 · v2.0.1Subscriber-facing copy now states what the subscription adds: editable Excel, Word, CSV and text exports, plus projects saved for editing later
- June 2026 · v2.0.0In the tool, the BS 7671 component tests now come first (BS EN 60332 flame, BS EN 61034-2 smoke at 60%, BS EN 60754-1 acid gas at 0.5%, added by A4:2026), with the Euroclass as the verification layer, because UK law sets no minimum class for internal wiring (BS 7671 Appendix 2 Item 17). You can now check a cable against a location or against a required class from your specification, on new tabs with validated presets.
- June 2026 · v1.2.3Power cable library expanded from Doncaster Declarations of Performance: split concentric, tri-rated, EV-Ultra, 3183Y flex and Tuff-Sheath. 26 cables
- June 2026 · v1.2.2Every datasheet-backed class now links to its source document, and the check shows the verified source for the cable you picked. 21 cables
- June 2026 · v1.2.1Print sheet fills the printable width and the cable library table renders full width; four more cables verified from their Declarations of Performance
- June 2026 · v1.2.0Print outputs the tab you are on rather than the last result; the checker and cable library become subscriber features with worked examples kept free
- June 2026 · v1.1.0Aligned to the Engineering Toolkit: editable Excel, Word, CSV and text exports and saved projects for subscribers, on a branded A4 sheet. Every Declaration of Performance link is now checked weekly and flagged when it dies
- June 2026 · v1.0.0First release: Understand, Choose, Validate and the cable library, with classes verified from Doncaster Declarations of Performance
