Coverage description
An Insurance Services Office (ISO) standard form. It replaces the umbrella pollution exclusion with a total pollution exclusion, keeping exceptions only for bodily injury inside a building from heating, cooling or dehumidifying equipment, and for injury or damage from most hostile fires.
Editions
Edition dates as filed, newest first. Filing counts include every state submission that lists the edition.
| Edition | Filings | Companies | States | Filed |
|---|---|---|---|---|
| 12 05Dec 2005Latest | 62 | 40 | 18 | May 2022 to Aug 2026 |
1 other edition date appears in one or two filings each, often carrier-specific versions: 07 04.
What the filings show
- Edition in use: in the past 12 months, 16 companies filed the 12 05 edition.
- CU 21 43 (Exclusion - Designated Products) is filed alongside it most often, in 61 of the same filings (97%).
Data from admitted P&C filings with state insurance departments, submitted Oct 2021 to Aug 2026, excluding withdrawn and rejected filings. One filing can cover several affiliated companies.
Carriers filing this form
The 10 carrier groups with the most filings that include CU 21 52, out of 25 in total.
| Carrier | Filings | States | Editions, most filed first | Last filed |
|---|---|---|---|---|
| Grinnell Mutual GroupGrinnell Mutual Reinsurance Company | 9 | 9 | 12 05 | Mar 22, 2023 |
| Nationwide Corporation Group4 group companies filed it, led by Nationwide Agribusiness Insurance Company and Crestbrook Insurance Company | 8 | 3 | 12 05 | Jun 30, 2026 |
| Tokio Marine Holdings Incorporated Group2 group companies filed it, led by Safety National Casualty Corporation and Philadelphia Indemnity Insurance Company | 7 | 3 | 12 05 | Aug 11, 2026 |
| Church Mutual GroupChurch Mutual Insurance Company, S.I. | 5 | 2 | 12 05 | Jun 26, 2026 |
| Sompo GroupSompo America Insurance Company | 5 | 1 | 12 05 | Jun 15, 2026 |
| James River GroupFalls Lake National Insurance Company | 4 | 4 | 12 05 | Jan 13, 2023 |
| AU Holding Company GroupContinental Indemnity Company | 3 | 3 | 12 05 | May 3, 2024 |
| American European Group2 group companies filed it, led by American European Insurance Company and Rutgers Casualty Ins Co | 2 | 2 | 12 05 | Apr 17, 2023 |
| American Family Insurance GroupMidvale Indemnity Company | 2 | 2 | 12 05 | Sep 28, 2023 |
| Copperpoint Group3 group companies filed it, led by Alaska National Insurance Company and CopperPoint Casualty Insurance Company | 2 | 1 | 12 05 | Jun 24, 2026 |
How the largest insurers handle CU 21 52
Groups among the largest commercial umbrella and excess insurers that filed CU 21 52 or their own version in the past five years.
- Chubb Limited GroupUses CU 21 52 in 1 filing
- Berkshire Hathaway GroupUses CU 21 52 in 1 filing
- WR Berkley Corporation GroupFiles its own version: CL CU 2317 Total Pollution Exclusion with a Building Heating, Cooling and Dehumidifying Equipment Exception and a Hostile Fire Exception (19 states)
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States
Number of filings that include CU 21 52 in each state, Oct 2021 to Aug 2026. Darker states have more filings.
Often filed with
Standard-style form numbers that appear in the same filings most often.
- CU 21 43Exclusion - Designated Products61 filings
- CU 21 07Contractual Liability Limitation59 filings
- CU 00 01Commercial Liability Umbrella Coverage Form58 filings
- CU 21 51Total Pollution Exclusion with a Hostile Fire Exception58 filings
- CU 24 23Coverage For Professional Services58 filings
- CU 21 13Amendment of Liquor Liability Exclusion54 filings
- CU 22 15Limitation Of Coverage - Real Estate Operations54 filings
- CU 21 14Amendment Of Liquor Liability Exclusion - Exception For Scheduled Premises Or Activities53 filings
- CU 21 23Nuclear Energy Liability Exclusion Endorsement52 filings
- CU 21 24Exclusion - Non-Owned Aircraft52 filings
Recent filings
Latest filings that include this form number. Filed copies open in FilingFocus.
| Submitted | Company | State | Editions | Tracking number |
|---|---|---|---|---|
| Aug 12, 2026 | Colonial Surety Company | SC | 12 05 | MRTN-134978915 |
| Aug 11, 2026 | Philadelphia Indemnity Insurance Company | SC | 12 05 | PHLX-135041545 |
| Jun 30, 2026 | The Medical Protective Companyand 1 more | IL | 12 05 | MDPC-135002488 |
| Jun 30, 2026 | Crestbrook Insurance Companyand 1 more | CO | 12 05 | NWPP-135003098 |
| Jun 26, 2026 | Church Mutual Insurance Company, S.I. | CO | 12 05 | CHMU-134995025 |
| Jun 24, 2026 | CopperPoint Casualty Insurance Companyand 1 more | SC | 12 05 | COPP-134996381 |
| Jun 19, 2026 | Addison Insurance Companyand 1 more | CO | 12 05 | UNFG-134979875 |
| Jun 15, 2026 | Sompo America Insurance Company | CO | 12 05 | SMPJ-134971280 |
| Jun 2, 2026 | Philadelphia Indemnity Insurance Company | IL | 12 05 | PHLX-134967828 |
| May 13, 2026 | Alaska National Insurance Company | SC | 12 05 | ALNI-134947655 |
| Apr 29, 2026 | Illinois EMCASCO Insurance Company | SC | 12 05 | EMCC-134929535 |
| Feb 17, 2026 | Safety National Casualty Corporation | CO | 12 05 | SFCC-134815068 |
Most filed ISO CU forms
- CU 34 54 Exclusion - Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)
- CU 21 86 Exclusion – Access Or Disclosure Of Confidential Or Personal Material Or Information
- CU 00 05 Exclusion - Violation of Law Addressing Data Privacy
- CU 34 56 Exclusion – Cyber Incident
- CU DS 01 Commercial Liability Umbrella Declarations
- CU 21 88 Exclusion - Access Or Disclosure Of Confidential Or Personal Material Or Information (Coverage B Only)
- CU 34 44 Broad Abuse or Molestation Exclusion
- CU 34 55 Exclusion - Electronic Data - Deletion Of Bodily Injury Exception
- CU 22 37 Motor Carrier Endorsement
- CU 21 87 Exclusion - Access Or Disclosure Of Confidential Or Personal Information and Data-Related Liability - Limited Bodily Injury Exception Not Included
- CU 04 02 Loss Of Electronic Data Resulting From Physical Injury To Tangible Property Liability Coverage - Subject To Cyber Incident Exclusion
- CU 04 54 Loss of Electronic Data Resulting From Physical Injury To Tangible Property Liability Coverage - Subject To Cyber Incident Exclusion - Deletion Of Bodily Injury Exception
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