Professionals must adhere to established codes and standards as they represent the minimum acceptable level of practice to ensure public safety. A deviation is only justifiable if it is based on sound professional judgment that the existing code is deficient, erroneous, or not applicable, and the deviation results in an equal or greater level of safety. Deviating from a code because it is viewed as "excessive" or to reduce costs for a client ("compromise their duty to client") is a violation of the paramount duty to protect the public. This subordinates public safety to a client's financial interests, which is unethical and unprofessional.

A. If a code's scope does not cover a specific design, it is not applicable, and deviation based on sound principles is necessary.

B. If a code is widely known to be deficient, adhering to it would be negligent; a professional must use a safer approach.

D. New research proving a standard is erroneous provides a strong, evidence-based reason to deviate in the interest of public safety.

1. Andrews, G. C. (2019). Canadian Professional Engineering and Geoscience: Practice and Ethics (6th ed.). Nelson. Chapter 5, "The Role of Technical Societies, Codes, and Standards," pp. 88-90.

2. Marston, D. L. (2016). Law for Professional Engineers (5th ed.). McGraw-Hill Ryerson. Chapter 11 discusses the standard of care, which includes following established codes unless there is a professionally sound reason to depart from them.

3. APEGS. (n.d.). Code of Ethics. The paramountcy of public safety would prohibit deviating from a safety standard for client-related cost or convenience reasons.