(CNN) -- A proposed health curriculum in Helena, Montana, public schools has riled up some parents who say it starts teaching students about sex far too early.
Several hundred parents in the mountain state's capital packed a school board meeting earlier this week to debate the 62-page proposal. It includes four pages of charts listing what elements of human sexuality should be introduced at which grades.
"Ninety-five percent, if not 99 percent, is really, really good stuff," Helena parent Brian Ackerman told HLN's "Prime News." But he added, "It's not something we can attach 100 percent agreement with all of the committee members."
The proposed curriculum guide is part of a broad range of health courses that also teach nutriition, disease prevention, anatomy and environmental health. It would teach students as early as second grade that using anti-gay slurs is hurtful and teach children in older elementary grades about sexual harassment and abuse.
Students would be told as early as kindergarten to properly name body parts. The concept that people "can love people of the same gender and people of another gender" would be introduced in first grade, though homosexual relationships aren't discussed until fifth grade.
Fifth-graders also would learn that sexual intercourse "includes but is not limited to vaginal, oral, or anal penetration." Teachers would start discussing pregnancy, sexually transmitted diseases and drugs and alcohol with middle-schoolers, while high school students would learn about sexual orientation and the "legal implications" of some decisions.
Ackeman, who has two elementary-age daughters and a third approaching kindergarten, said parents should be told "who decided this, when did they decide it and how did they decide it?"
"We really haven't seen where that age-appropriateness comes from," he said. In addition, he said the district has not figured out how to implement the program.
"There isn't any sort of implementation in place right now that says this is how we're going to teach this," Ackerman said.
Bruce Messinger, Helena's school superintendent, said the guide was drawn up by a committee that included parents, teachers and administrators. That committee used local practices and examined national guidelines, including those put out by the American Academy of Pediatrics, he said.
"It establishes that between the ages of kindergarten through grade 4, vocabulary would be introduced so a student has an understanding," Messinger said. "It doesn't specifically say what would happen."
Implementation plans will be developed later, he said -- and if parents object, he added, "They have a right to opt out."
The last school board meeting drew not only critics but supporters. And Cathy Areu, publisher of the Latina women's magazine Catalina and a former high school teacher, told HLN the standards sound defensible and age-appropriate.
"It sounds like they are teaching body parts and things that are facts of life," Areu said. "I feel more comfortable with my daughter learning about this in a classroom than from a boy in the hallway."