School children need to be taught about the impact of porn as part of the national curriculum.
The National Association of Headteachers (NAHT) says more young people are now getting information about sex from online and sex education guidelines are out of date.
Policy adviser Sion Humphreys said: "Children are growing up in an overtly sexualised world.
"That includes easy access to porn and they need the skills to deal with it. "
"We would support children being taught in an age-appropriate way about the impact of pornography as part of a statutory Personal Social Health Education (PSHE) programme. "
He said that lessons could start from primary school but that the material would depend on age.
"Evidence suggests 10 isn't too young to start lessons on pornography, but it wouldn't be a full on lesson but the grounding would be laid down."
At the moment, PSHE, which includes sex and relationships education, is not compulsory in England unlike other parts of the UK.
Biological facts are part of all lessons in secondary school science lessons.
Beyond that parents have the right to withdraw their children from any sex education.
But The National Union of Teachers say referring to issues of porn in lessons is a step too far and that schools should only talk about it if asked by students.
The Department of Education wouldn't comment on the impact of porn in lessons, but said it's up to individul schools on how the teach sex education.
Wales, Scotland and Northern Ireland also say policies should be devised by schools.
LAW ABOUT PORN IN THE UK
Teenagers are also taught in the Family Lives class about the law when it comes to porn and adult content.
Can I look at porn legally?
In the UK it is legal to look at porn on TV and online so long as it does not feature under 18s, sex with animals, torture, scenes of rape or sexual assault or violent scenes which are life threatening or likely to cause serious harm.
What's the law regarding porn on TV?
Porn can be shown on UK TV after 9pm so long as it does not show erect penises or close ups of genitals.
Can I buy porn?
The legal age is 18 to buy porn magazines or videos. Most porn websites try to prevent under 18s from accessing them, either through charging with a credit card or by a disclaimer on the front page.
What if I'm under 18 and film porn?
Young people under 18 who film or take sexual pictures of each other can be charged with child porn offences, even if they both agreed to it.
What about being under 18 and watching porn?
Also illegal to watch with someone under 18 (even they are both under 18 and both wanted to watch it), this is intended to prevent abuse of children and young people.