# EDGAR Filing Document

**Accession Number:** 0001880319
**File Stem:** 0001352561-26-000002
**Filing Date:** 2026-3
**Character Count:** 9696
**Document Hash:** 7b3f7f74d72d0f95f706e5039089a3e2
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001352561-26-000002.hdr.sgml**: 20260302

**ACCESSION NUMBER**: 0001352561-26-000002

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260226

**FILED AS OF DATE**: 20260302

**DATE AS OF CHANGE**: 20260302

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Henderson Robert S
- **CENTRAL INDEX KEY:** 0001352561

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-41027
- **FILM NUMBER:** 26709625

**MAIL ADDRESS:**
- **STREET 1:** ADELWIGGINS GROUP
- **STREET 2:** 5000 TRIGGS STREET
- **CITY:** LOS ANGELES
- **STATE:** CA
- **ZIP:** 90022
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Perimeter Solutions, Inc.
- **CENTRAL INDEX KEY:** 0001880319
- **STANDARD INDUSTRIAL CLASSIFICATION:** CHEMICALS & ALLIED PRODUCTS [2800]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 332098357
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 8000 MARYLAND AVE., SUITE 350
- **CITY:** CLAYTON
- **STATE:** MO
- **ZIP:** 63105
- **BUSINESS PHONE:** (314) 396-7343

**MAIL ADDRESS:**
- **STREET 1:** 8000 MARYLAND AVE., SUITE 350
- **CITY:** CLAYTON
- **STATE:** MO
- **ZIP:** 63105

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Perimeter Solutions, SA
- **DATE OF NAME CHANGE:** 20210826

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Henderson Robert S<br><sub>(Last) (First) (Middle)</sub><br>C/O PERIMETER SOLUTIONS, INC<br>8000 MARYLAND AVE., SUITE 350<br><sub>(Street)</sub><br>CLAYTON, MO 63105<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-02-26 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Perimeter Solutions, Inc. [ PRM ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |  |  |  |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Stock Option (right to buy) | $27.84 | 2026-02-26 |  | A |  | 2655<sup>(1)</sup> |  | 2026-02-26 | 2035-12-23 | Common Stock | 2655 | $0 | 2655 | D |  |
| Stock Option (right to buy) | $11.80 | 2026-02-26 |  | A |  | 6194<sup>(2)</sup> |  | 2026-02-26 | 2035-02-12 | Common Stock | 6194 | $0 | 6194 | D |  |
| Stock Option (right to buy) | $5.23 | 2026-02-26 |  | A |  | 7000<sup>(3)</sup> |  | 2026-02-26 | 2034-02-14 | Common Stock | 7000 | $0 | 14000 | D |  |
| Stock Option (right to buy) | $5.50 | 2026-02-26 |  | A |  | 7000<sup>(4)</sup> |  | 2026-02-26 | 2033-09-06 | Common Stock | 7000 | $0 | 21000 | D |  |
| Stock Option (right to buy) | $8.88 | 2026-02-26 |  | A |  | 7000<sup>(5)</sup> |  | 2026-02-26 | 2033-02-15 | Common Stock | 7000 | $0 | 21000 | D |  |
| Stock Option (right to buy) | $12.09 | 2026-02-26 |  | A |  | 7000<sup>(6)</sup> |  | 2026-02-26 | 2032-01-28 | Common Stock | 7000 | $0 | 28000 | D |  |
| Stock Option (right to buy) | $11.80 | 2026-02-26 |  | A |  | 1750<sup>(7)</sup> |  | 2026-02-26 | 2031-12-07 | Common Stock | 1750 | $0 | 7000 | D |  |

---

### Footnotes:

(1) On December 23, 2025, the reporting person was granted an option to purchase 15,000 shares of common stock. The option vests in five equal annual installments based on the Issuer's satisfaction of certain performance criteria for each of the fiscal years ending December 31, 2025, 2026, 2027, 2028 and 2029. The performance criteria for 2025 were partially met, resulting in the vesting of the option as to 2,655 shares of common stock.

(2) On February 12, 2025, the reporting person was granted an option to purchase 35,000 shares of common stock. The option vests in five equal annual installments based on the Issuer's satisfaction of certain performance criteria for each of the fiscal years ending December 31, 2025, 2026, 2027, 2028 and 2029. The performance criteria for 2025 were partially met, resulting in the vesting of the option as to 6,194 shares of common stock.

(3) On February 14, 2024, the reporting person was granted an option to purchase 35,000 shares of common stock. The option vests in five equal annual installments based on the Issuer's satisfaction of certain performance criteria for each of the fiscal years ending December 31, 2024, 2025, 2026, 2027 and 2028. The performance criteria for 2025 were met, resulting in the vesting of the option as to 7,000 shares of common stock.

(4) On September 6, 2023, the reporting person was granted an option to purchase 35,000 shares of common stock. The option vests in five equal annual installments based on the Issuer's satisfaction of certain performance criteria for each of the fiscal years ending December 31, 2023, 2024, 2025, 2026 and 2027. The performance criteria for 2025 were met, resulting in the vesting of the option as to 7,000 shares of common stock.

(5) On February 15, 2023, the reporting person was granted an option to purchase 35,000 shares of common stock. The option vests in five equal annual installments based on the Issuer's satisfaction of certain performance criteria for each of the fiscal years ending December 31, 2023, 2024, 2025, 2026 and 2027. The performance criteria for 2025 were met, resulting in the vesting of the option as to 7,000 shares of common stock.

(6) On January 28, 2022, the reporting person was granted an option to purchase 35,000 shares of common stock. The option vests in five equal annual installments based on the Issuer's satisfaction of certain performance criteria for each of the fiscal years ending December 31, 2022, 2023, 2024, 2025 and 2026. The performance criteria for 2025 were met, resulting in the vesting of the option as to 7,000 shares of common stock.

(7) On December 7, 2021, the reporting person was granted an option to purchase 8,750 shares of common stock. The option vests in five equal annual installments based on the Issuer's satisfaction of certain performance criteria for each of the fiscal years ending December 31, 2022, 2023, 2024, 2025 and 2026. The performance criteria for 2025 were met, resulting in the vesting of the option as to 1,750 shares of common stock.

**Signature:** /s/ Noriko Yokozuka, as Attorney-in-Fact  
**Date:** 2026-03-02

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**