Slime, glorious slime

It's easy to understand why slime has become such a popular resource with children in the last couple of years. Squishy, stretchy, jiggly or like putty, it's fascinating to manipulate, deeply mysterious and curiously addictive!

Slime Planet, located at Loughborough Junction in south London, runs activites and workshops for pre-schoolers and KS1 and 2 pupils.
Slime Planet, located at Loughborough Junction in south London, runs activites and workshops for pre-schoolers and KS1 and 2 pupils.

Other versions of slime used to be known as gloop or oobleck. Gloop is an interesting mixture with a unique texture and is great for sensory play. It is also great for learning about the concepts of solid and liquid. This was basically a corn starch and water mix and used in settings a great deal with under fives to encourage them to explore by directly experiencing.

Oobleck was the name given to a type of slime in a Dr. Seuss book (1949) that was capable of gumming up a whole kingdom. Oobleck is a non-Newtonian fluid, it has properties of both liquids and solids. You can slowly dip your hand into it like a liquid, but if you squeeze the oobleck or punch it, it will feel solid.

The educational benefits of using slime:

Sensory play allows children to use descriptive expressive language and helps them nd a sense of meaning behind a word. Take for instance the word ‘slimy.’ If a child never felt coloured slime, how would he be able to describe it? Playing with slime allows children to experience the texture and the sensation. Once they experience it, then they can describe it with words and their own thoughts. is will build children’s vocabulary and help increase their understanding of new words.

Cognitive skills:
These skills are developed by children having control of their actions and experiences, providing them with the con dence that they can create and design all while enjoying sensory play.

Fine motor:
Fine motor skills are developed while children are squeezing, pinching, picking up, and moving the goo back and forth. is activity will not only strengthen their small muscles, but it will help develop their pencil grip, which sets them up for greater success when manipulating a pencil.

Social and emotional
Skills are developed by children having control of their actions and experiences, providing them with confidence that they can create and simply explore without set outcomes. Slime was a big favourite last year and it was good to see a diversion away from electronic toys and a return to a sensory messy play.

The open-ended play that occurs with a resource such as slime means that children can work alone or cooperate if they wish, and explore at varying levels. Using slime allows for child-initiated activity opportunities.

Some issues to consider with messy play
Some children do not like contact with some materials, not just slime, sand and water play can present some anxiety. ere may be various reasons for this. One solution can be touch through using a tool to avoid direct contact. Using gloves as a barrier, for example, may start giving them the necessary confidence and is a strategy to try. It may be that some children are not allowed to get messy at home and so using aprons can help protect their clothes. Asking parents to be mindful that in the setting there will be opportunities to get messy can also help.

All the above may seem contradictory to the actual hands on experience of sensory play but I found in working with settings that you come across some children that struggle with experiencing messy play while others love it – each child is unique.

Another strategy with very sloppy slime is placing it in a plastic sealed bag. This allows children to press squeeze and manipulate the slime to some degree.

Health and safety warnings
When a trend such as slime appears, there are many companies producing and selling it. And, in the case of slime, it unfortunately brought with it some warnings as a result of some of the products containing borax. This prompted a Which? report on the products on sale. The EU safety standard specifies that toy slimes must have boron levels that fall below 300mg/kg and toy putties must have boron levels that fall below 1,200mg/kg. Exposure to excessive levels of boron could cause irritation, diarrhoea and vomiting in the short term, and may impair fertility and cause harm to unborn children in pregnant women.

For more information on boron levels in commercial slime, you can access the Which (2018) report 

Why does slime contain boron?
Borax (a compound of boron) is used in slime to give it its gelatinous texture. Borax and other derivatives of boron, such as boric acid are found in several products around the home, such as pesticides, face creams, contact lens solution, household cleaners and laundry detergent.

Some of the products on sale are safe but not all. Check on the Which website as they break down their results and they name the safe acceptable products. 

Homemade slime
Making your own safe slime is one of the answers. Or you can choose to use the slime products that have been evaluated as safe.
There are various recipes which you can try and use with peace of mind as you are sure of its contents.

Aside from the question of safety, which is paramount when working with children, you may also want to consider whether your slime is environmentally-friendly.

Some of the ingredients in slime can be particularly harmful to the environment when it is thrown away. For example, slime made from glue essentially consists of creating a big lump of plastic. ere are quite a few recipes using PVA glue out there.

Slime recipes

  • Borax free version

What you will need:
1 cup of cornstarch/corn our. • 1 cup of spinach – packed.
1/2 cup of water.

Place the spinach and water into your food processor. Puree.
Place your mixture into a bowl. Whisk together with cornstarch or corn our, adding gradually until you have a thick ‘slime- like’ concoction.

  • Below are some
    other Borax free versions of slime .

Start clean: Hand soap slime
2–4 tbsps oil (I used

olive oil).
2 tsps food colouring. • 7–10 tbsps cornstarch/

corn flour
1/3 cup hand soap (you
can use any you like).

Mix all the ingredients together knead them to form a ball of slime. is hand soap slime requires no glue just hand soap and corn-starch/ corn our with some oil to make this slime not so sticky. If you would like to play with this slime, make sure you are gentle with it and if it dries out just add more oil. Baby oil is the best oil to use. The oil really makes this slime smooth and fun to play with. There are various hand soaps on the market. Choosing di erent ones will add variety to the slime you produce. Some of these will have fragrances. The oil really makes this slime smooth and fun to play with. I really enjoy the beautiful colours of this slime and would recommend that you try making it. It can really keep children and adults occupied for hours and is very relaxing.

  • Shampoo Slime Recipe

What you need:
Clear shampoo (or mostly clear). • Sugar.
Plastic cup.

For the shampoo slime recipe – Pour about a half a cup of shampoo into a plastic cup. You can use more shampoo, but it will take longer to develop, and you might want the shampoo to clean your hair later.

Add a teaspoon of sugar and mix. e shampoo will thicken almost right away. Add a bit more sugar until the mixture clings to the spoon similar to wet slime. Place the cup in the freezer for 2 hours the slime will thicken – remove and stretch and play with it.

1. Always make sure that what you use with children is safe, contains only safe products and ingredients. Consider what each product has or each recipe as some children have allergies.
2. Know your children’s allergies – ensure all staff members have this knowledge, especially supply staff or volunteers
3. Discourage children from eating any slime
4. Encourage children to wash their hands after using slime. 
5. Store slime well so that it will last longer and can be reused.

ThoughtCo. Easy oobleck recipe–make non-newtonian slime

Bartholomew and The Oobleck by Dr Seuss Published by Penguin Random House (ISBN: 978-0394900759)

The Slime Book is a recipe book. Published by DK Children (ISBN: 978-0241336618

Cornstarch or cornflour, spinach, oil, hand soap, food colouring and other ingredients to make slime.

Containers for storing slime.

Gloves for children who are not confident enough to manipulate it directly

Find out more about activities and workshops at Slime Planet here


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