Which of the following actions can lead to a certification being affected?

Failing the written examination directly impacts certification status because it is a fundamental requirement to demonstrate knowledge of the relevant laws, procedures, and operation of the Intoxilyzer 9000. Certification is contingent upon successfully passing this exam to ensure that individuals are adequately prepared to operate the equipment and interpret results correctly. Without this knowledge, there is a higher risk of errors in testing, which can lead to inaccurate results and legal consequences, ultimately affecting the individual's certification and ability to perform breath alcohol testing.

In contrast, actions such as using proper equipment, following established procedures, and demonstrating proficiency contribute to maintaining certification rather than jeopardizing it. These actions are critical to ensuring that tests are conducted accurately and effectively, aligning with best practices and legal standards in breath alcohol testing.