Expandable water toys (also grow-in-water toys or grow monsters) are

novelty item A novelty item is an object which is specifically designed to serve no practical purpose, and is sold for its uniqueness, humor, or simply as something new (hence "novelty", or newness). The term also applies to practical items with fanciful or ...

s made from a

superabsorbent polymer A superabsorbent polymer (SAP) (also called slush powder) is a water-absorbing hydrophilic homopolymers or copolymers that can absorb and retain extremely large amounts of a liquid relative to its own mass. Water-absorbing polymers, which are cl ...

. They are toys that expand after putting them into water for anything from a few hours up to several days, depending on size. They shrink in saltwater or when exposed to air. They are made from polymers that can absorb and retain extremely large amounts of a liquid relative to their own mass.

Description

Water Balz look like

marbles A marble is a small spherical object often made from glass, clay, steel, plastic, or agate. These toys can be used for a variety of games called marbles, as well being placed in marble runs or races, or created as a form of art. They are ofte ...

, but expand to , the size of a

racquetball Racquetball is a racquet sport and a team sport played with a hollow rubber ball on an indoor or outdoor court. Joseph Sobek invented the modern sport of racquetball in 1950, adding a stringed racquet to paddleball in order to increase vel ...

, in water. Orbeez expand to in water. Expandable water toys are also sold in the shapes of other things, such as dinosaurs, sharks, people or

mecha In science fiction, or mechs are giant robots or machines, typically depicted as piloted, humanoid walking vehicles. The term was first used in Japanese (language), Japanese after shortening the English loanword or , but the meaning in Japan ...

s from popular

anime is a Traditional animation, hand-drawn and computer animation, computer-generated animation originating from Japan. Outside Japan and in English, ''anime'' refers specifically to animation produced in Japan. However, , in Japan and in Ja ...

. Many of the companies that distribute them are Chinese and Dutch trading companies.

History

The introduction and popularity of these toys has followed the development of superabsorbent polymers. In the early 1970s, the superabsorbent polymer was used commercially for the first time for disposable hygienic products. The first product markets were feminine sanitary napkins and adult incontinence products. The development of superabsorbent technology and performance has been largely led by demands in the disposable hygiene segment. Strides in absorption performance have allowed the development of the ultra-thin baby

diaper A diaper (, North American English) or a nappy (British English, Australian English, Hiberno-English) is a type of underwear that allows the wearer to urinate or defecate without using a toilet, by absorbing or containing waste products to p ...

which uses a fraction of the materials – particularly fluff pulp – that earlier disposable diapers consumed. Over the years, technology has progressed so that there is little if any starch-grafted superabsorbent polymer used in disposable hygienic products. These super absorbents typically are cross-linked acrylic homo-polymers (usually sodium neutralized).

Risks and recalls

Larger versions of the expandable toys can become lodged in the guts of children. Water Balz and Orbeez have been swallowed and lodged in the guts of children, requiring surgery to remove. A 2012 paper documented the case of an infant who had swallowed a "Water Balz" product, which grew to "the size of a golf ball" in her digestive tract, requiring surgery to remove it. Orbeez states that their product expands to only in the intestines if swallowed and will pass through the digestive tract, but that it is a choking hazard and is unsuitable for children under five. Starting from January 15, 2007 there have been several recalls on these toys. Ireland, Poland, Cyprus, Lithuania, Hungary and the United Kingdom have recalled the Magic Grow Reptile and Dinosaur Eggs Wild World due to a

choking Choking, also known as foreign body airway obstruction (FBAO), is a phenomenon that occurs when breathing is impeded by a blockage inside of the respiratory tract. An obstruction that prevents oxygen from entering the lungs results in oxygen de ...

risk. In the United Kingdom, an expanding spider toy was recalled in 2010 for not complying with the European standard

EN 71 European standard EN 71 specifies safety requirements for toys. It is harmonised with the Toy Safety Directive (Council Directive 2009/48/EC) and compliance with the standard is legally required for toys sold in the European Union The Eu ...

, in that the toy's legs could be broken off and swallowed, expanding in the stomach. In 2022, the "Orbeez Challenge" encouraged people to shoot one at strangers with gel-ball guns, or

airsoft Airsoft, also known as survival game () in Japan where it was popular, is a team sport, team-based shooting sport, shooting game in which participants eliminate opposing players out of play by shooting them with airsoft pellets, spherical plast ...

guns, filled with Orbeez.

References

{{reflist 1970s toys Water toys Novelty items Polymer physics Toy recalls