Ontario has updated its sexual-education curriculum for the first time in nearly two decades and it will be rolled out across the province this fall.

Education Minister Liz Sandals unveiled the new curriculum at a news conference Monday, saying the government won't back down in the face of criticism as it did in 2010 when religious groups complained about proposed revisions.

Sandals said she anticipates some criticism, but the new lessons are key to keeping children safe.

"This will be the curriculum that is taught in Ontario schools in September 2015," Sandals said, noting training for teachers has already been scheduled.

Sandals said many aspects of the curriculum, like telling children they have the right to say no to unwanted touching, remains the same. However, because of public health data that shows children are experiencing puberty earlier, some topics are being introduced at earlier ages.

'Kids start asking about things very, very early in terms of their own sexuality.' — Dr. Miriam Kaufman, SickKids Hospital

"We need to deal with the fact that our kids are starting to go through puberty much younger than they used to," said Sandals.

The new curriculum, which marks the first time sex-education courses in Ontario have been updated since 1998, also includes more information about the role technology plays in youth sexuality.

Sandals said she hopes frank discussions about the risks of sharing explicit content online will cut down on the inappropriate material children are sharing online.

At the legislature, opposition members appeared on board with the notion that Ontario's sex-ed curriculum was in need of an update.

"There's no way that we should be operating with 1998 curriculum," NDP Leader Andrea Horwath said Monday.

PC education critic Garfield Dunlop said he was "pleased parents finally have chance to review sex-ed curriculum."

Children have questions about sex: experts

Many people who work in the sexual-education field praised the changes on Monday.

Lyba Spring, who has worked as a sex educator with Toronto Public Health for some 30 years, said Ontario’s curriculum is the oldest in Canada and 16 years out of date.

Spring said the number 1 issue the curriculum needs to address is consent.

Currently, she said, "there’s no encouragement to really think through what one is willing to do."

Spring said classes should also discuss pornography and sexting, and that there should be a section about sexual abuse in the puberty section.

And, Spring said, teachers should be ready to answer questions.

"They're exposed to everything on the internet … but they want to hear it from a teacher," Spring said.

Dr. Miriam Kaufman, the head of adolescent medicine at SickKids Hospital, said it's natural for children and youth to have questions about sex.

"Kids start asking about things very, very early in terms of their own sexuality," said Kaufman.

Those questions shouldn’t be left for parents to answer, she said.

"The parent role is essential … but as parents we're not all that good," Kaufman said, noting that while she's written books on the topic and taught classes, she wasn't good at speaking with her own children about sex.

Parents will get resources, too

Ahead of Monday's news conference, The Canadian Press obtained a copy of a "quick facts" guide for parents that outlines some of the changes, including many that relate to technology.

The guide says students in grades 1, 2 and 3 will learn initial searching skills and strategies for safe internet use, including "how to get help for themselves or others if harassment or abuse happens either face-to-face or online."

The primary grade students will also learn the difference between real and fictional violence, in the media or with online games, and "respectful communications" in the gym, classroom and school yard.

Even some elementary school students have sent sexually explicit pictures of themselves to someone online, while 11 per cent of Grade 10 students and about 14 per cent of those in Grade 11 say they have sent a sext, according to a 2015 study, Young Canadians in a Wired World.

"As students get older, they are more likely to sext," the guide warns parents. "Many students are unaware of the potential effects and consequences of sexting."

With files from The Canadian Press and the CBC's Charlsie Agro and Mike Crawley