EXHIBIT 23.1 CONSENT OF INDEPENDENT ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in this Registration Statement of ChiRex Inc. on Form S-3 to register $100,000,000 worth of securities of our report dated February 4, 1998 included in ChiRex Inc.'s Form 10-K for the year ended December 31, 1997 and to all references to our Firm included in this registration statement. /s/ Arthur Andersen LLP Arthur Andersen LLP December 10, 1998 Boston, Massachusetts