**EXHIBIT 99.5**

 

**CERTIFICATIONS**

 

I, Jeffrey M. Lipton, certifythat:

 

1.             I have reviewed this annual report on Form 40-Fof NOVA Chemicals Corporation;

 

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

 

3.             Based on my knowledge, the financialstatements, and other financial information included in this report, fairlypresent in all material respects the financial condition, results of operationsand cash flows of the issuer as of, and for, the periods presented in thisreport;

 

4.             The issuer’s other certifying officer and I areresponsible for establishing and maintaining disclosure controls and procedures(as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) andinternal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and15d-15(f)) for the issuer andhave:

 

a)             Designed such disclosure controlsand procedures, or caused such disclosure controls and procedures to bedesigned under our supervision, to ensure that material information relating tothe issuer, including its consolidated subsidiaries, is made known to us byothers within those entities, particularly during the period in which thisreport is being prepared;

 

b)            Designedsuch internal control over financial reporting, or caused such internal controlover financial reporting to be designed under our supervision, to providereasonable assurance regarding the reliability of financial reporting and thepreparation of financial statements for external purposes in accordance withgenerally accepted accounting principles;

 

c)             Evaluated the effectiveness of theissuer’s disclosure controls and procedures and presented in this report ourconclusions about the effectiveness of the disclosure controls and procedures,as of the end of the period covered by this report based on such evaluation;and

 

d)            Disclosed in this report any changein the issuer’s internal control over financial reporting that occurred duringthe period covered by the annual report that has materially affected, or isreasonably likely to materially affect, the issuer’s internal control overfinancial reporting; and

 

5.             The issuer’s other certifyingofficer and I have disclosed, based on our most recent evaluation of internalcontrol over financial reporting, to the issuer’s auditors and the auditcommittee of the issuer’s board of directors (or persons performing theequivalent functions):

 

a)             all significant deficiencies andmaterial weaknesses in the design or operation of internal control overfinancial reporting which are reasonably likely to adversely affect the issuer’sability to record, process, summarize and report financial information; and

 

b)            any fraud, whether or not material,that involves management or other employees who have a significant role in theissuer’s internal control over financial reporting.

 

 
| Date:  March 1, 2006 | */s/ Jeffrey M. Lipton*        |   |
|---------------------------|--------------------------------|--------|
|                      | Jeffrey M.  Lipton             |
|                      | Chief  Executive Officer       |
|                      | (Principal  Executive Officer) |

 

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I, Larry A. MacDonald, certifythat:

 

1.             I have reviewed this annual report on Form 40-Fof NOVA Chemicals Corporation;

 

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

 

3.             Based on my knowledge, the financialstatements, and other financial information included in this report, fairlypresent in all material respects the financial condition, results of operationsand cash flows of the issuer as of, and for, the periods presented in thisreport;

 

4.             The issuer’s other certifying officer and I areresponsible for establishing and maintaining disclosure controls and procedures(as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) andinternal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and15d-15(f)) for the issuer andhave:

 

a)             Designed such disclosure controlsand procedures, or caused such disclosure controls and procedures to bedesigned under our supervision, to ensure that material information relating tothe issuer, including its consolidated subsidiaries, is made known to us byothers within those entities, particularly during the period in which thisreport is being prepared;

 

b)            Designedsuch internal control over financial reporting, or caused such internal controlover financial reporting to be designed under our supervision, to providereasonable assurance regarding the reliability of financial reporting and thepreparation of financial statements for external purposes in accordance withgenerally accepted accounting principles;

 

c)             Evaluated the effectiveness of theissuer’s disclosure controls and procedures and presented in this report ourconclusions about the effectiveness of the disclosure controls and procedures,as of the end of the period covered by this report based on such evaluation;and

 

d)            Disclosed in this report any changein the issuer’s internal control over financial reporting that occurred duringthe period covered by the annual report that has materially affected, or isreasonably likely to materially affect, the issuer’s internal control overfinancial reporting; and

 

5.             The issuer’s other certifyingofficer and I have disclosed, based on our most recent evaluation of internalcontrol over financial reporting, to the issuer’s auditors and the auditcommittee of the issuer’s board of directors (or persons performing theequivalent functions):

 

a)             all significant deficiencies andmaterial weaknesses in the design or operation of internal control overfinancial reporting which are reasonably likely to adversely affect the issuer’sability to record, process, summarize and report financial information; and

 

b)            any fraud, whether or not material,that involves management or other employees who have a significant role in theissuer’s internal control over financial reporting.

 

 
| Date:  March 1, 2006 | */s/ Larry A. MacDonald*       |   |
|---------------------------|--------------------------------|--------|
|                      | Larry A.  MacDonald            |
|                      | Chief  Financial Officer       |
|                      | (Principal  Financial Officer) |

 

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