Consent of Independent Registered Public Accounting Firm EXHIBIT 23(a)

We consent to the incorporation by reference of our reports dated February 9, 2017, relating to (i) consolidated financial statements and financial statement schedule (which report expresses an unqualified opinion and includes an explanatory paragraph regarding a change in accounting policy from expensing asbestos-related defense and processing costs as incurred to the accrual of asbestos-related defense and processing costs when probable of occurring and estimable) of The Dow Chemical Company and subsidiaries (the “Company”), and (ii) the effectiveness of the Company's internal control over financial reporting, appearing in this Annual Report on Form 10-K of The Dow Chemical Company for the year ended December 31, 2016, in the following Registration Statements of The Dow Chemical Company:

Form S-3:
No.	333-214289
Form S-4:
No.	333-88443
	333-209869
Form S-8:
Nos.	33-21748
	33-52841
	33-61795
	333-27381
	333-40271
	333-43730
	333-67414
	333-91027
	333-103518
	333-103519
	333-105080
	333-122932
	333-145015
	333-162910
	333-181356
	333-207634
	333-209581
	333-209582

/s/ DELOITTE & TOUCHE LLP

Deloitte & Touche LLP

Midland, Michigan

February 9, 2017

185