Slime could contain unsafe levels of chemicals, study finds

child playing with slime

Consumer group Which? says some children's slime toys could contain dangerous levels of boron, a chemical which can cause vomiting and affect fertility

Finding ways to entertain the kids can be tough, but slime never fails to do the trick: the sticky, squishy substance keeps children happily occupied for hours, leaving parents plenty of time to check Mumsnet prep packed lunches in peace. A new study, however, has exposed potential dangers in the substance and prompted some retailers to withdraw certain brands from sale. The testing was carried out by Which? and involved assessing 11 popular slime products for boron, a highly alkaline household cleaner and a common ingredient in slime because it helps to create stickiness.

Exposure to excessive levels of boron can cause irritation, vomiting and cramping. High levels can also impair fertility and cause harm to unborn babies in pregnant women, according to the European Commission.

Eight out of the 11 products tested exceeded the EU safety limit of 300mg/kg, and can be seen below in red.

slime results

The worst product, Toysmith Jupiter Juice, had more than four times the permitted level of boron. Eight of the products which contained potentially unsafe levels of boron were purchased on Amazon. They have since been removed from sale.

Two high-street retailers, The Works and Smyths, both sell slime that was found to be within the safety limit when tested.

slime results

Nikki Stopford, Director of Research and Publishing at Which?, said:

''If you have school-age kids, you're probably very well aware of the latest slime craze sweeping the playgrounds. Kids love it.

Parents buying slime for their children should have peace of mind that these toys are safe, so they will be shocked to find that the health of their children could be put at risk by these slimes.''

Which? was particularly concerned that not only do many slime products contain minimal safety labelling and information about the ingredients, some of the brands tested self-certified their packaging to indicate that the products were safe, despite the fact that the levels of boron were too high.

''There must be fundamental changes to the product safety system,'' added Ms Stopford.

''Manufacturers must stop making unsafe products and the government and retailers simply have to do a far better job of getting anything identified as a risk off the shelves and out of people's homes.''

In response to the findings, Amazon said: “All Marketplace sellers must follow our selling guidelines and those who don’t will be subject to action including potential removal of their account. The products in question are no longer available."

child playing with slime

Some parents have chosen to make their own slime, but that can also be dangerous.

Last year an 11-year-old from Massachusetts reportedly developed third-degree burns while mixing together the ingredients. Another parent on Facebook said that her daughter also suffered similar injuries after using boron. There are, however, many alternative recipes for slime which don't contain boron.

WikiHow's How to Make Slime Without Borax lists four different recipes, using ingredients such as cornflour and condensed milk to create the same texture.