A new California sex education guidance encourages teachers to talk to kindergartners about gender identity and middle-schoolers about masturbation, worrying some education leaders who say the nation’s largest school system is pulling them into conversations they don’t want to have with children in their classrooms.

After a contentious hearing Wednesday, the California State Board of Education approved the guidance. It endorses ideas of gender fluidity and sex positivity and posits what some see as alarming scenarios, such as a health teacher discussing nonmonogamous relationships.

The guidance for teachers of the Golden State’s 6.2 million public school children has elicited concerns from social conservatives and traditional family groups that what happens in California doesn’t stay there.

“When ‘pleasure-based’ and ‘consent-based’ sex ed is discovered at a school, parents are rightly furious,” said Cathy Ruse, a legal fellow with the Family Research Council. “Only parents know their own children and know whether material might be too much, too soon for their child.”

Proponents of “comprehensive sex education” are cheering California’s decision, though they don’t necessarily see a wave of sex education classes using the guidance as a model sweeping the nation.

Jessica Sales, an associate professor at the Rollins School of Public Health at Emory University, said some “more progressive states or other states along the West Coast” may follow California’s lead, but historically it has not been the case that the state’s sex education policies have been copied and applied widely across the country.

The more than 700-page guidance says its goal is “health literacy for all students in California.” It covers a variety of factors, including automobile safety and the dangers of obesity and sleep deprivation. It is designed as a guide for teachers to meet state standards on health education in topics such as nutrition, physical activity, and combating alcohol and drug abuse.

Most of the attention, however, has focused on sex education. During Wednesday’s hearing in Sacramento, critics asked the state board about LGBTQ-friendly policies. Some parents held up copies of a book that an earlier draft of the guidance recommended, “S.E.X.: The All-You-Need-to-Know Sexuality Guide to Get You Through Your Teens and Twenties,” which includes descriptions of anal sex, bondage and other acts, The Associated Press reported.

The book did not appear as a recommendation in the final version of the guidance.

Among the sharpest critics of the policy was Rebecca Friedrichs, founder of For Kids & Country, who said California had “proven its blind devotion to state and national teachers unions” and noted a victory for its “radical, social, sexual and political beliefs.”

Supporters of the board’s approach also spoke out. Transgender teenager Phoenix Ali Rajah said the state’s curriculum has had a heteronormative bias.

“I’m never taught about how to be in a relationship with gay men,” said Phoenix, adding that a “conversation with sex starts from a different place.”

Ms. Sales told The Washington Times that the evidence suggests that addressing sex in an open manner, even masturbation with middle-schoolers, alleviates shame and misunderstanding.

“Ask any pediatrician, and they will tell you that children explore their bodies, and it’s a part of growing up,” she said. “But somehow when you say that in a school, you’ve gone too far?”

Proponents argue that comprehensive sex education classes are more effective than abstinence-only classes at preventing sexually transmitted diseases and unwanted pregnancies. Comprehensive classes venture beyond basic anatomy and disease prevention to include curricula designed in the wake of the #MeToo movement and the Supreme Court’s 2015 decision in Obergefell v. Hodges, which legalized same-sex marriage nationwide.

A few states and the District of Columbia have endorsed teaching sex education with a more inclusive bent.

Thirty-seven states require that abstinence be included in sex education classes, but only 17 of those states also require teachings of contraception, according to ThoughtCo.com, a global education reference website.

Meanwhile, 10 states have adopted legislation to halt the teaching of what they call “transgender theory” in public school classrooms.

“Gender identity activists behind the California program and elsewhere are really pushing an ideology, not a science-based curriculum,” said the Family Research Council’s Ms. Ruse. “There is no science to back up the claim that some people are born in the wrong body.”

The California guidance offers topics and teaching scenarios for health classrooms. For example, in a hypothetical lesson on healthy eating, a primary school teacher asks her students to examine whether advertisements for sugary cereals are manipulative.

Textbooks are suggested but not required on a variety of topics. For discussing various types of families, teachers are encouraged to use different books, including actress Jamie Lee Curtis’ 2006 children’s book, “Is There Really a Human Race?”

The 2017 book “Who Are You?: The Kid’s Guide to Gender Identity,” by Brook Pessin-Whedbee, is listed as an option for a sex education class.

The guidance also provides dramatic instruction, with seventh- and eighth- graders asked to act out scenarios to teach appropriate behavior. The scenario descriptions include “Two students are at a party. One asks the other for oral sex,” and “Daughter asks mom if she will take her to get birth control. Mom replies, ‘Why do you want birth control? Are you having sex?’”

Read more at ‘Too much, too soon’? California slammed for kindergarten gender identity talks in sex education.