Section 16. The department may, after hearing or waiver thereof, revoke or refuse to renew a certification, certificate of inspection, license, designation or other approval for failure to perform such requirements as set forth in such certificate, license, designation, or other approval, for violation of any applicable requirement prescribed under this chapter, for violation of a correction order, or for engaging in, or for aiding, abetting, causing, or permitting, any act prohibited under this chapter or under any other general or special law or other applicable legal requirement related to the operation of any element of the EMS system. The commissioner may without hearing, suspend a certification, certificate of inspection, license, designation or other approval held by any person if he finds that such person is acting pursuant to such certification, operating or maintaining an EMS vehicle subject to such certificate of inspection, maintaining a service subject to such license, or acting pursuant to any designation or other approval, in a manner which endangers the public health or safety; provided, however, that in every case of suspension the person certified, licensed, designated or otherwise approved by the department under this chapter shall be promptly afforded an opportunity for a hearing under this section. If after any hearing hereunder concerning a certification, license, designation or other approval, the department determines that cause exists, instead of revoking or refusing to renew such certification, license, designation or other approval, the department may issue an order modifying the certification, license, designation or other approval if it finds that the public interest would be better served by such action. No certificate of inspection under a license shall continue in force after the department has suspended, revoked or refused to renew such license.