DOCPROPERTY "CUS_DocIDChunk0" 01015877.3

Attention: ​, PhD, Founder, President and Chief Executive Officer

Amendment to the ​ Amended and Restated Employment Agreement between ​ and ​ PhD

THIS FIRST AMENDMENT TO EMPLOYMENT CONTRACT (this "First Amendment"), effective as of ​, is made and entered into by and between Trecora Resources, a Delaware corporation ("Company"), and Peter Loggenberg, PhD. ("Loggenberg").

Date. Whenever any payment due hereunder shall fall due on a day other than a Business Day, such payment shall be made on the next succeeding Business Day, and such extension of time shall be included in the computation of interest or fees, as the case may be.

administration using Clearside’s proprietary microinjector,” said Yusuf Ali, PhD, Vice President, Research and Development at Santen. “We look forward to expanding our relationship with Clearside to investigate Clearside’s proprietary methods of accessing the SCS for the treatment of additional blinding diseases such as glaucoma.”

Date of Adoption, Effective Date. The Plan was adopted by the Board of Directors of the Company on ​, and will become effective on ​, if approved by the shareholders of the Company on ​ in accordance with applicable law (such approval date, the “Effective Date”).

Expiration Date. Each Letter of Credit shall expire at or prior to the close of business on the earlier of # the date twelve months after the date of the issuance of such Letter of Credit (or, in the case of any renewal or extension thereof, twelve months after such renewal or extension, so long as such renewal or extension occurs within three months of such then current expiration date) and # the date that is five Business Days prior to the Commitment Termination Date; provided, however, that any Letter of Credit with a one-year term may, upon the request of the Borrower, include a provision whereby such Letter of Credit shall be renewed automatically for additional consecutive periods of one year or less (but not beyond the date that is five Business Days prior to the Commitment Termination Date) unless the Issuing Bank notifies the beneficiary thereof at least 30 days prior to the then-applicable expiration date that such Letter of Credit will not be renewed; provided, further, however, that a Letter of Credit may expire after the date that is five Business Days prior to the Commitment Termination Date, subject to the Borrower’s obligation to cash collateralize such Letter of Credit as provided in the last paragraph of [Section 2.09(a)].

Effective Date. The provisions of this [Article IV] A will apply for purposes of determining required minimum distributions for calendar years beginning with the 2003 calendar year.

Effective Date. The Plan was adopted by the Board effective as of the Effective Date.