We have acted as counsel to SenesTech, Inc., a Delaware corporation (the “Company”), in connection with the filing with the Securities and Exchange Commission (the “Commission”) of a Registration Statement on Form S-3 (the “Registration Statement”) pursuant to the Securities Act of 1933, as amended (the “Securities Act”), for the registration of the sale from time to time of (a) shares of common stock, par value $0.001 per share (the “Common Stock”), of the Company; (b) shares of preferred stock, par value $0.001 per share (the “Preferred Stock”), of the Company; (c) warrants of the Company (the “Warrants”), which may be issued pursuant to a warrant agreement (the “Warrant Agreement”) between the Company and a warrant agent to be named therein (the “Warrant Agent”); and (d) units (the “Units”) to be issued under one or more unit agreements (each such unit agreement, a “Unit Agreement”) to be entered into among the Company, a bank or trust company, as unit agent (the “Unit Agent”), and the holders from time to time of the Units.

In connection therewith, we have examined originals, or copies certified or otherwise identified to our satisfaction, of the following: (i) the Registration Statement; (ii) the Company’s Amended and Restated Certificate of Incorporation, as amended to the date hereof; (iii) the Company’s Amended and Restated Bylaws, as amended to the date hereof; and (iv) such other documents, corporate records, certificates of public officials and other instruments as we have deemed necessary or advisable for the purpose of rendering this opinion.

In rendering the opinions expressed herein, we have, without independent inquiry or investigation, assumed that (i) all documents submitted to us as originals are authentic and complete, (ii) all documents submitted to us as copies conform to authentic, complete originals, (iii) all documents filed as exhibits to the Registration Statement that have not been executed will conform to the forms thereof, (iv) all signatures on all documents that we reviewed are genuine, (v) all natural persons executing documents had and have the legal capacity to do so, (vi) all statements in certificates of public officials and officers of the Company that we reviewed were and are accurate, and (vii) all representations made by the Company as to matters of fact in the documents that we reviewed were and are accurate.

Based upon the foregoing, and subject to the additional assumptions and qualifications set forth below, we advise you that, in our opinion:

1. When the necessary corporate action on the part of the Company has been taken to authorize the issuance and sale of such shares of Common Stock proposed to be sold by the Company, and when such shares of Common Stock are issued and delivered in accordance with the applicable underwriting or other agreement against payment therefor (in excess of the par value thereof) or upon conversion or exercise of any security offered under the Registration Statement (the “Offered Security”), in accordance with the terms of such Offered Security or the instrument governing such Offered Security providing for such conversion or exercise as approved by the Board of Directors of the Company, for the consideration approved by the Board of Directors of the Company (which consideration is not less than the par value of the Common Stock), such shares of Common Stock will be validly issued, fully-paid and non-assessable.

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2. Upon designation of the relative rights, preferences and limitations of any series of Preferred Stock by the Board of Directors of the Company and the proper filing with the Secretary of State of the State of Delaware of a Certificate of Designation relating to such series of Preferred Stock, and when the necessary corporate action on the part of the Company has been taken to authorize the issuance and sale of such series of Preferred Stock proposed to be sold by the Company, and when such shares of Preferred Stock are issued and delivered in accordance with the applicable underwriting or other agreement against payment therefor (in excess of the par value thereof), such shares of Preferred Stock will be validly issued, fully-paid and non-assessable.

3. When the Warrant Agreement to be entered into in connection with the issuance of any Warrants has been duly authorized, executed and delivered by the Warrant Agent and the Company, the specific terms of the Warrants have been duly authorized and established in accordance with the Warrant Agreement, and such Warrants have been duly authorized, executed, issued and delivered in accordance with the Warrant Agreement and the applicable underwriting or other agreement against payment therefor, such Warrants will constitute valid and binding obligations of the Company, enforceable in accordance with their terms, subject to applicable bankruptcy, insolvency and similar laws affecting creditors’ rights generally, concepts of reasonableness and equitable principles of general applicability.

4. When the Unit Agreement to be entered into in connection with the issuance of any Units has been duly authorized, executed and delivered by the Unit Agent and the Company, the specific terms of the Units have been duly authorized and established in accordance with the Unit Agreement, and such Units have been duly authorized, executed, issued and delivered in accordance with the Unit Agreement and the applicable underwriting or other agreement against payment therefor, such Units will constitute valid and binding obligations of the Company, enforceable in accordance with their terms, subject to applicable bankruptcy, insolvency and similar laws affecting creditors’ rights generally, concepts of reasonableness and equitable principles of general applicability.

In connection with the opinions expressed above, we have assumed that, at or prior to the time of the delivery of any such security, (i) the Board of Directors of the Company shall have duly established the terms of such security and duly authorized the issuance and sale of such security and such authorization shall not have been modified or rescinded; (ii) the Company shall remain validly existing as a corporation in good standing under the laws of the State of Delaware; (iii) the Registration Statement shall have become effective and such effectiveness shall not have been terminated or rescinded and the Registration Statement will comply with all applicable laws at the time securities are offered or issued as contemplated by the Registration Statement; (iv) a prospectus supplement shall have been prepared and filed with the Commission describing the securities offered thereby and shall comply with all applicable laws; (v) the Warrant Agreement is a valid, binding and enforceable agreement of each party thereto (other than as expressly covered above in respect of the Company); (vi) the Unit Agreement is a valid, binding and enforceable agreement of each party thereto (other than as expressly covered above in respect of the Company); and (vii) there shall not have occurred any change in law affecting the validity or enforceability of such security. We have also assumed that the execution, delivery and performance by the Company of any security whose terms are established subsequent to the date hereof (a) require no action by or in respect of, or filing with, any governmental body, agency or official (other than as expressly covered above); and (b) do not contravene, or constitute a default under, any public policy, any provision of applicable law or regulation or any judgment, injunction, order or decree or any agreement or other instrument binding upon the Company.

Greenberg Traurig, LLP \| Attorneys at Law
2375 East Camelback Road \| Suite 800 \| Phoenix, Arizona 85016 \| T +1 602.445.8000 \| F +1 602.445.8100
	www.gtlaw.com

This opinion is limited to the matters stated herein, and no opinions may be implied or inferred beyond the matters expressly stated herein. We assume no obligation to update or supplement this opinion to reflect any facts or circumstances that may hereafter come to our attention or any changes in law that may hereafter occur.

We render this opinion with respect to, and express no opinion herein concerning the application or effect of the law of any jurisdiction other than, the existing laws of the United States of America, and of the Delaware General Corporation Law, the Delaware Constitution and reported judicial decisions relating thereto.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement referred to above and further consent to the reference to our name under the caption “Legal Matters” in the prospectus, which forms a part of the Registration Statement. In giving this consent, we do not admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act.

Greenberg Traurig, LLP \| Attorneys at Law
2375 East Camelback Road \| Suite 800 \| Phoenix, Arizona 85016 \| T +1 602.445.8000 \| F +1 602.445.8100
	www.gtlaw.com

	Very truly yours,

	/s/ Greenberg Traurig, LLP