Some of the UK’s largest retailers have agreed to voluntarily stop sales of acids to customers under 18 years old.
The move comes amid continuing concern over the use of corrosive substances as a weapon.
In the year to last April, police recorded more than 500 attacks in England and Wales, double the number five years ago, with the majority of incidents in London.
A fifth of attackers who had been identified were under 18 years old.
The true level of acid crimes may be much higher than official records show.
A Freedom of Information request found the Metropolitan Police alone recorded more than 450 noxious or corrosive fluid incidents in London in 2016.
A Home Office analysis estimated the true national rate could be as high as 900 crimes a year.
The Home Office has already proposed new legislation to ban the sale of corrosive substances to under-18s as well as an additional offence of possession in a public place without good reason.
This would bring the law for household acids and harmful chemicals that are not already subject to legal restrictions into line with crimes relating to knives.
The public consultation on that proposal, which would have to go through Parliament, closed last month.
In the meantime, DIY chains B&Q, Screwfix and Wickes, along with Waitrose, Morrisons and the Co-Op have committed to impose their own voluntary bans on sales to under-18s.
The British Independent Retailers Association, which includes independent DIY and hardware shops, will also ask its members to sign up to the new voluntary ban.
Under it, retailers will agree not to sell to under-18s any of their products that contain harmful levels of acid or other corrosive substances, such as powerful drain cleaners.
Staff will be expected to challenge buyers to prove their age in the same way that they do for solvents, spray paints and knives.
Crime minister Victoria Atkins said: “I’m pleased that so many of the UK’s major retailers are joining our fight… and signalling they are committed to selling acids responsibly.
“This is the next step of our acid attacks action plan that has already seen us consult on new laws to restrict young people’s access to acids.”
But former chief prosecutor for the North West, Nazir Afzal, says the voluntary ban does not go far enough.
He said shops will not be sanctioned if they do not abide by the rules.
He added: “The other issue is online; I checked and you can buy sulphuric acid at 96% strength, which will burn your face off, for £10 on next day delivery.
“Until you tackle that issue, you’re only playing with it rather than tackling it.”
The Home Office has also said experts at the University of Leicester are beginning detailed research into the characteristics and motivations of attackers.
Acid or other corrosive chemicals have been a weapon in a range of crimes, including revenge, so-called “honour crimes”, gang violence and theft from delivery drivers.
In one of the most serious recent cases, a man who threw acid in a packed London nightclub, injuring 22 people, was jailed for 20 years.
Another man is facing trial later this year for the alleged murder of a woman who died after she was splashed with a corrosive substance.