Giant internet companies should do more to prevent web pages promoting the use of laughing gas, according to the Local Government Association (LGA).
Katie Hall, chairwoman of the LGA's Community Wellbeing Board said: "We are particularly concerned about internet pages and uploaded clips which are effectively 'promoting' this as a harmless drug."
She added: "The web giants must do more to crack down on this, they cannot simply sit on their hands and ignore what is happening on their own sites.
"We are calling on the big internet corporations to step up to the plate and show responsibility by providing health warnings and links to drug awareness charities. It is wholly unacceptable that this craze is being glamorised and encouraged in this way."
More top news
Some 66 people have been killed after the plane they were travelling on crashed in southern Iran.
The letter calls for an end to harassment, abuse, and impunity in a world "ripe for change".
Police say that anyone who sees Whitehouse should not approach him, but instead call them on 999 and quote incident 23 of 18 February.