Water Beads and Super Absorbent Polymers (SAP): An expanding problem?
Written by Nathan Klein, University of Washington PharmD candidate with contributions from Christopher Dayringer, University of Washington PharmD candidate and Curtis Elko, PharmD, Washington Poison Center Certified Specialist in Poison Information
What are Super Absorbent Polymers?
Super Absorbent Polymers (SAP) or “water beads” are plastic-like materials that absorb hundreds of times their weight in aqueous fluids (water) and expand in size to form a semi-solid gel-like material. Used primarily in disposable diapers and sanitary napkins, niche markets have also emerged, including water bead toys, sensory toys, cold packs, vase fillers, and stress balls. Manufacturers label many of these products as “non-toxic,” which can lead to a false sense of security among parents and caregivers. If swallowed, SAP may expand as they travel along the digestive tract, potentially leading to a bowel obstruction and serious, life-threatening complications. Water bead exposures are challenging to manage as symptoms are rarely immediate, with some exposures taking up to 7 days to present symptoms.
How often does SAP ingestion lead to a serious event?
The United States Consumer Product Safety Commission recently estimated 7,800 water bead exposures were evaluated in hospital emergency departments from 2016–2022. These national estimates are concerning but provide little evidence for the degree and likelihood of harm after SAP exposure.
A retrospective review of the National Poison Data System (all certified poison centers in the United States) found 5,805 water bead toy exposure cases between January 2019 and December 2022 in children less than 6 years old. Cases increased each year, with the rate doubling between 2020 and 2022. Poison centers managed 83.5% of the cases at home. Sixty-two cases (1.1%) required hospital admission and 16 cases (0.27%) required bead removal or other surgical management. This data estimated the prevalence of a procedure or surgical intervention at 1 in 370 SAP exposures.
A recent review article identified 43 published cases of bowel obstruction after a SAP ingestion among children ages 6–36 months. All cases with bowel obstructions reported persistent vomiting. Additional symptoms included abdominal distension (65%), constipation (26%), diarrhea (2%), abdominal pain (2%), and dehydration (33%). Enterotomy (84%), resection (12%), and endoscopy (4%) were performed to remove the beads. Most cases had favorable outcomes, but two cases resulted in fatality likely due to delayed presentation or missed diagnosis.
Washington Poison Center report of SAP exposure
While these cases remain a small part of our practice, reports to the Washington Poison Center (WAPC) are increasing.
Nearly 75% of WAPC’s SAP exposure cases are for patients 4 years of age or younger (Figure 2).
Among the 1,051 SAP exposures reported to the WAPC from January 1, 2006 — November 10, 2023, one exposure led to a confirmed intestinal obstruction requiring surgical management. Transient or minor gastrointestinal effects such as nausea, vomiting, abdominal pain, constipation and diarrhea occurred in 12% of cases. WAPC managed 85% of cases at home.
The overall low incidence of significant complications may have resulted from a short observation period. The WAPC now recommends a one-week period of observation at home for asymptomatic patients, with WAPC staff checking in with the family throughout. Close monitoring will lessen the risk of unrecognized problems and help establish the true incidence of delayed adverse events.
What to do if a child ingests SAP
If any of the following symptoms are present following a suspected SAP exposure, we recommend immediate referral to a health care facility:
- Inability to talk/vocalize
- Dysphagia
- Drooling (excessive or more than normal)
- Dyspnea, gasping, stridor, wheezing
- Choking
- Persistent vomiting
- Hematemesis
- Nasal or otic insertion
Call the Washington Poison Center at 1–800–222–1222 for evaluation and treatment recommendations appropriate to the patient’s potential exposure, age, and symptoms.
When there are no symptoms following a SAP ingestion, contact the Washington Poison Center at 1–800–222–1222. We will provide instructions for home observation and follow up with the family for 7 days.
Conclusion
Super absorbent polymers present a unique challenge: the products are not toxic and usually do not cause initial symptoms. However, expansion within the intestinal tract happening days later may cause great harm if not recognized and treated, especially with children younger than 4 years old. The best option is to prevent the child’s exposure by closely monitoring play and storing products out of a child’s reach. If an exposure does occur, we are ready to help. Call us 24/7/365 at 1–800–222–1222.
References
1. Chazovachii, P.T., Somers, M.J., Robo, M.T. et al. Giving superabsorbent polymers a second life as pressure-sensitive adhesives. Nat Commun 12, 4524 (2021). https://doi.org/10.1038/s41467-021-24488-9
2. Caré W, Dufayet L, Paret N, Manel J, Laborde-Casterot H, Blanc-Brisset I, Langrand J, Vodovar D. Bowel obstruction following ingestion of superabsorbent polymers beads: literature review. Clinical Toxicology. 2022 60:2, 159–167.
3. https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Water-Beads-Information-Center
4. Dong C, Chambers A, Kershner E, Rose R, Cumpston K, Wills B. Outcomes of ingested superabsorbent polymers (“water beads”): a single poison center study. Clinical Toxicology. 2023 61:sup2, 1–186.
5. Novak M, Chhabra N, Wahl M. Pediatric exposures to expandable water beads reported to US poison centers. Clinical Toxicology. 2023 61:sup2, 1–186.
