A festival is considering offering drug content testing facilities, after a call by experts who said it would reduce the risk of serious harm.
Green Man Festival in Brecon, Powys, might introduce the tests after the Royal Society for Public Health said people should be able to find out if substances were safe.
But Festival Number 6 in Portmeirion, Gwynedd, has ruled it out.
Drug charities have raised concerns, saying it could encourage drug use.
The RSPH said allowing festival-goers to check the content and strength of substances they possess should also be introduced in city centres where drug use in clubs is common.
It said the idea was supported by the majority of clubbers and festival-goers.
Testing was piloted at Secret Garden Party and Kendal Calling festivals in 2016.
Fiona Stewart, from Green Man Festival, told BBC Wales’ Jason Mohammad programme on Thursday they were discussing the proposal with police.
“Anything that’s going to educate people better and give them a better understanding of using their bodies and what they’re putting in their mouth is something good, but it’s not something they’ve pressed on us or asked us to do,” she said.
“I think the issue of drugs, although it’s everywhere, Green Man isn’t one of those events where it’s been a particular problem over the years.”
She stressed that drug taking was not an issue isolated to festivals, adding that testing should be introduced at all large events.
Festival No.6 organiser Luke Huxham said they were committed to providing “an enjoyable and secure environment” and would not be offering any testing facilities.
He said: “Working closely with local police and other agencies, a strict policy is enforced to minimise the use of illegal substances.”
This includes “searches upon entry, monitoring of all attendees through CCTV, covert and overt security, and protection on-site with medical provisions in place for any customer who may incur ill effects from taking illegal substances”, he added.
Clive Wolfendale, the chief executive of north Wales drug charity CAIS, said he “didn’t really accept” that the move would reduce drug taking.
“I have seen far too many die from long-term addiction, or through taking tainted or over-strength drugs, or simply the devastation that occurs when people take it for many, many years,” he said.
“We need an adult conversation about it but what we need are policies which actually dissuade people from doing it rather than encouraging it.
“So when we hear about festivals offering drug screening I really do worry because this is about encouraging drugs, this is creating drug fest and a bit of a free for all, and it’s exactly what, in my view, we don’t need.”