(1) No insurer shall cancel a policy of insurance that provides coverages on commercial exposures such as general comprehensive liability, municipal liability, automobile liability and physical damage, fidelity and surety, fire and allied lines, inland marine, errors and omissions, excess liability, products liability, police liability, professional liability, or false arrest insurance unless such insurer mails by first-class mail to the named insured, at the last address shown in the insurer's records, at least forty-five days in advance a notice of the company's intention to cancel; but, where cancellation is for nonpayment of premium, at least ten days' notice of cancellation accompanied by the reasons therefor shall be given.

(2) A notice of cancellation pursuant to this section shall be valid only if it is based on one or more of the following reasons:

(a) Nonpayment of premium;

(b) A false statement knowingly made by the insured on the application for insurance;

(c) A substantial change in the exposure or risk other than that indicated in the application and underwritten as of the effective date of the policy unless the insured has notified the insurer of the change and the insurer accepts such change.

(3) This section shall not apply to insurance companies authorized to write surplus line insurance in Colorado.

(4) This section shall not apply to insurers providing coverage for exempt commercial policyholders, as defined pursuant to section 10-4-1402 and rules adopted by the commissioner pursuant to that section.