Exhibit 12
                                   ----------


                Certification Required by 18 U.S.C. Section 1350
     (as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002)


I, Lee Hartwell, certify that:

1. I have reviewed this annual report on Form 20-F of Hemosol Inc.;

2. Based on my knowledge, this annual report does not contain any untrue
statement of a material fact or omit to state a material fact necessary to make
the statements made, in light of the circumstances under which such statements
were made, not misleading with respect to the period covered by this annual
report;

3. Based on my knowledge, the financial statements, and other financial
information included in this annual report, fairly present in all material
respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this annual report;

4. I am responsible for establishing and maintaining disclosure controls and
procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
registrant and have:

           a.   designed such disclosure controls and procedures to ensure that
                material information relating to the registrant, including its
                consolidated subsidiaries, is made known to me by others within
                those entities, particularly during the period in which this
                annual report is being prepared;

           b.   evaluated the effectiveness of the registrant's disclosure
                controls and procedures and presented in this annual report our
                conclusions about the effectiveness of the disclosure controls
                and procedures, as of the end of the period covered by this
                annual report based on such evaluation; and

           c.   disclosed in this annual report any change in the registrant's
                internal control over financial reporting that occurred during
                the period covered by the annual report that has materially
                affected, or is reasonably likely to materially affect, the
                company's internal control over financial reporting; and;

5. I have disclosed, based on my most recent evaluation, to the registrant's
auditors and the audit committee of registrant's board of directors (or persons
performing the equivalent function):

           a.   all significant deficiencies and material weakness in the design
                or operation of internal controls which are reasonably likely to
                adversely affect the registrant's ability to record, process,
                summarize and report financial data; and

           b.   any fraud, whether or not material, that involves management or
                other employees who have a significant role in the registrant's
                internal controls over financial reporting.


Date: June 30, 2004

                                By: /s/ LEE HARTWELL
                                    -----------------------------------------
                                Name: Lee Hartwell
                                Title: President, Chief Executive Officer and
                                       Chief Financial Officer