Power of Attorney

Know all by these presents, that the undersigned hereby
constitutes and appoints Roger Jackson, General Counsel of KMG
Chemicals, Inc. (the "Company"), the undersigned's true and
lawful attorney-in-fact to:

(1)	execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer of the Company, Forms 3, 4
and 5 in accordance with Section 16(a) of the Securities Exchange
Act of 1934, as amended, and the rules thereunder;

(2)	do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and
execute any such Form 3, 4 or 5 and timely file such form with
the United States Securities and Exchange Commission and any
stock exchange or similar authority; and

(3)	take any other action or any type whatsoever in connection
with the foregoing which, in the opinion of such attorney-in-
fact, may be of benefit to, in the best interest of, or legally
required by, the undersigned, it being understood that the
documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such
form and shall contain such terms and conditions as such
attorney-in-fact may approve in such attorney-in-fact's
discretion.

The undersigned hereby grants to each attorney-in-fact full power
and authority to do and perform any and every act and thing
whatsoever requisite, necessary or proper to be done in the
exercise of any of the rights and powers herein granted, as fully
to all intents and purposes as the undersigned might or could do
if personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's substitute or
substitutes, shall lawfully do or cause to be done by virtue of
this power of attorney and the rights and powers herein granted.
The undersigned acknowledges that the foregoing attorney-in-fact,
in serving in such capacity at the request of the undersigned,
are not assuming, nor is the Company assuming any of the
undersigned's responsibilities to comply with Section 16 of the
Securities Exchange Act of 1934.

This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3, 4
and 5 with respect to the undersigned's holdings of and
transaction in securities issued by the Company, unless earlier
revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of the 20th day of May, 2007.

		/s/ Stephen A. Thorington
	Signature
	Stephen A. Thorington
Company Name
Date
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