(NewsNation) — Updates to USA Boxing’s rulebook have sparked criticism over the federation’s policy regarding transgender athletes.

The policy was written in 2022 but added to the federation’s rulebook this week. It’s based on the November 2021 International Committee Framework on Fairness, Inclusion and Non-Discrimination on the Basis of Gender Identity and Sex Variations. That framework allows the international federation for each sport to determine transgender athletes’ eligibility.

“Since boxing’s IF has not determined transgender eligibility and boxing is considered a combat sport, USA Boxing’s overriding objective is the safety of all boxers and fair competition between all boxers,” USA Boxing wrote in an August 2022 release.

Boxer Mikaela Mayer was among the critics who called the policy unfair.

“Hormone therapy is banned,” Mayer wrote on X. “By default this should make trans athletes ineligible for competition. Period. Doesn’t matter how you feel about the situation, fact is, it’s illegal & completely disrupts the even level playing field that sport works so hard to create.”

Others worried the policy would give transgender female athletes an unfair advantage and potentially put boxers in danger.

USA Boxing did not immediately respond to NewsNation’s email seeking comment. The federation has previously said the rules were created to “provide fairness and safety for all boxers.

Per the federation’s policy, minors must compete as the gender assigned to them at birth. USA Boxing will only communicate with minors while a parent or guardian is present.

A normal range of testosterone for adult boxers is considered more than 10 nanomoles per liter (nmol/L) for male athletes and less than 3.1 nmol/L for female athletes, according to the policy. Those figures are based, in part, on studies from the Boston Children’s Hospital Sports Medicine Division and Harvard Medical School Teaching Hospital.

A boxer who transitions from male to female is eligible to compete if they have “declared that her gender identity is female” and has completed gender reassignment surgery, according to the policy. Male-to-female boxers also must undergo quarterly hormone testing and present USA Boxing with documentation of their hormone levels for at least four years after surgery.

They must additionally show their testosterone level has been below 5 nmol/L for at least 48 months before their first competition and the entire time they compete in the female category.

Compliance will be monitored by testing at the athlete’s expense. The federation will suspend a noncompliant athlete’s eligibility for female competition for 12 months. The boxer’s hormones must then be retested after that period.

The same conditions apply for boxers who transition from female to male, except their testosterone levels must remain above 10 nmol/L.