Fad over fatality? The hazards of amber teething necklaces

Abstract

Objective

Despite a growing number of injuries, no studies exist to date that quantitatively assess the strangulation risk of amber teething necklaces. The objectives of this study are to determine (a) if these necklaces release with the force required according to the American Society for Testing and Materials (ASTM) Standard Specification for Consumer Product Safety for Mechanical Requirements of Children’s Jewelry, and (b) if they release with the mean force required to occlude a young child’s airway, as determined in a study designed to inform manufacturing of products to reduce risk of accidental strangulation.

Methods

Fifteen amber teething necklaces were purchased from retailers in Atlantic Canada. Necklaces were tested using the Breakaway Tension Test method reported in ASTM guidelines. Necklaces were tested with a 15 pound weight (industry standard) and with a 1.6 pound weight (mean force required to occlude a child’s airway). It was recorded whether the necklace released or remained intact at the end of each trial.

Results

Seven of fifteen necklaces did not open with 15 lbs of force. Eight of 10 necklaces tested did not open with 1.6 lbs of force.

Conclusion

Almost 50% of our sample failed to open with 15 pounds of force, which is the force used in the ASTM standard for children’s jewelry. Eighty per cent of our sample failed to open with 1.6 pounds of force, which was the mean force to occlude a young child’s airway in a published study. These necklaces pose a strangulation risk to young children if they were to become caught.

Amber teething necklaces have widespread use as a natural health product to relieve the symptoms of childhood teething. They are intended to fit such that children cannot chew the beads, but are to remain against the child’s skin throughout the teething process (Figure 1). A Pubmed search reveals no scientific evidence to demonstrate that such use is effective as an analgesic, while reports of infants being accidentally strangled are beginning to emerge (1–3). Despite the lack of evidence of benefit, these necklaces are widely available at parenting stores and from online shops which espouse their purported effects.

Figure 1.

Small boy wearing an Amber Teething Necklace.

Some advocates and retailers of these amber necklaces claim the necklaces break at tensions lower than would create a strangulation risk. For example, one Canadian retailer’s website contains the quote “the necklace breaks if pulled too hard. Hence there is no threat of accidental choking or strangulation” (4). Other retail sites report that the necklace is unlikely to break, thereby minimizing the risk of choking on a free bead (5).

Parents may assume products available for purchase have been tested and are safe; however, no anti-strangulation safety requirements for children’s jewelry are included in the Canada Consumer Product and Safety Act (6). Similarly, in the United States, manufacturers are only encouraged (not required) to comply with a product safety standard outlining anti-strangulation measures (Personal communication (email) with William Cussey, Acting Small Business Ombudsman, U.S. Consumer Product Safety Commission. June 10, 2016.) (7). Health Canada recommends to “never place a necklace, teething necklace, string, ribbon or chain around the neck of a child under three” (8), and released a specific Consumer Product Safety Advisory advising families not to use teething necklaces (9). The Canadian Paediatric Society specifically recommends against the use of amber necklaces (10). Similar safety warnings about amber necklaces have been made by other organizations internationally due to concern about possible strangulation and/or choking (11,12).

To date, there are no available published studies which test the force required to release or open the clasps of amber necklaces to assess the strangulation risk they pose to the infants and children intended to wear them. In this investigation, we determine (a) if amber teething necklaces purchased in Atlantic Canada release with the force required according to the American Society for Testing and Materials (ASTM) Standard Specification for Consumer Product Safety for Mechanical Requirements Children’s Jewelry (5) (15 pounds [6.80 kg]) and (b) if amber teething necklaces purchased in Atlantic Canada release with a force of 1.6 pounds (0.73 kg), which was the mean force required to occlude a young child’s airway as determined by Stevens et al. in a study designed to inform design and manufacturing of products to reduce risk of accidental strangulation (13).

MATERIALS AND METHODS

Materials

Amber teething necklaces were purchased from retailers in Halifax Regional Municipality, Nova Scotia, and Fredericton, New Brunswick, Canada. Necklaces sold for $20–40 CAD each. We obtained necklaces from different local retailers based on a convenience sample of nearby retailers.

Method

The ASTM is an international organization which develops consensus standards for a wide range of industries ‘to improve product quality, enhance health and safety, strengthen market access and trade and build consumer confidence’ (14). It has produced a standard for Consumer Product Safety for Children’s Jewelry in which it states:

12.2.1 Children’s jewelry intended to be attached around the neck shall release, either by designed breakaway feature, attachment design or physical properties of the material, when subjected to 15 lb of tension in accordance with the breakaway tension test described in 13.1 (7).

13.1 Breakaway Tension Test—Using a 1.5- ± 0.1-in. radius free pulley, apply 15 lb force to the looped jewelry, with the other end looped around a 0.170 ± 0.01 in. radius fixed rod. Apply the 15 lb force over 5 s and hold for 10 s. ^8(p8)

The ‘Breakaway Tension Test’ described above was assembled by an engineer at the Department of Materials Engineering at the University of New Brunswick (Figure 2).

Figure 2.

ASTM Breakaway Tension Test*. *Reprinted, with permission, from ASTM F2923–11 Standard Specification for Consumer Product Safety for Children’s Jewelry, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM, www.astm.org. ASTM American Society for Testing and Materials.

Fifteen necklaces were tested by suspending a 15 pound (6.80 kg) weight for 10 seconds. Ten necklaces were tested by suspending a 1.6 pound (0.73 kg) weight for 10 seconds. After each trial, it was recorded if the necklace opened or remained intact.

RESULTS

Description of necklaces

The majority of amber necklaces purchased were displayed without packaging; as such it was not possible to determine the number of manufacturers sampled. The necklaces varied in length (10.5 to 14 cm), colour(s) of amber and clasp type (Figure 3).

Figure 3.

Examples of Necklaces (screw-clasp top, pop-clasp bottom).

Break away testing results

Fifteen necklaces were tested with a breakaway test using 15 pounds (6.80 kg) of force over 10 seconds. Seven had a screw clasp and eight had pop clasps. Within the trial, eight released, seven (7/15) did not. Of the eight necklaces that released during testing, seven had pop-clasps and one had a screw clasp. The screw clasp necklace which opened did not release at the clasp. Rather, the string adjacent to the clasp broke. No bead was released from this site.

Ten necklaces were tested with a breakaway test using 1.6 pounds (0.73 kg) of force over 10 seconds. Five had a screw clasp and five had pop clasps. Within the trial, two released, eight (8/10) did not. Both of the necklaces which opened had pop clasps.

DISCUSSION

Outside of advisories against use, little has been published in the medical literature about teething necklaces. One study interviewed a group of parents whose children were observed wearing teething necklaces in hospital (15). The most common parental perception about the necklaces related to their analgesic properties. The authors noted that when informed of the dangers of strangulation, numerous families preferred to continue using the necklaces. Another article described a 10-month old seen in a paediatric clinic wearing a teething necklace, whose mother stated she would normally remove the necklace prior to medical appointments where doctors might notice the jewelry (16).

Recommendations advising against the use of amber necklaces note the risk of strangulation and/or choking (8–12). A recent case report describes the nonfatal strangulation of a 4-month-old infant who presented to the Emergency Department with a petechial rash on his face after wearing an amber teething necklace overnight (1). Two reports have been published in the media: one of an 18-month-old boy in California who was fatally strangled by an amber teething necklace during his nap (2) and another of a 15-month-old Australian toddler who became tangled in her teething necklace also during a nap (3).

Infants are known to be at risk of strangulation as they develop increased mobility without the skills to extricate themselves should they become trapped. From 1991 to 2000, the US Consumer Product Safety Commission received reports of 130 strangulations involving cords on window blinds (17). At least 22 American children have died from strangulation related to drawstrings on clothing. One report describes a 9-month-old child who was wearing a pacifier on a cord around his neck (18). He was found hanging from the pacifier cord which had caught in the playpen corner. With knowledge of such cases it should be easy to see that amber necklaces pose a similar risk of strangulation.

There is no requirement for anti-strangulation safety standards in children’s jewelry in Canada. For our testing we chose to use the standard developed by American Society for Testing and Materials which is a suggested, but not mandatory, standard for American children’s jewelry. In our sample, 7 of the 15 necklaces tested failed to release at 15 pounds of force (the antistrangulation standard developed by American Society for Testing and Materials). However, given that many internet sites claim that necklaces are safe as they would open before strangulation could occur, failure of 47% of tested necklaces to meet this standard may be helpful in convincing parents to follow recommendations of Health Canada and others (8–12).

In addition to testing against an industry standard, our goal was to test the necklaces against a clinically relevant force. A study by Stevens et al. attempted to determine the external pressure required to occlude a child’s airway to better understand the mechanism of accidental hangings/strangulations (13). Using a population of ninety children under age 6 years undergoing elective surgical procedures, they determined the mean force to occlude the airway was only 1.6 pounds. This was affected by age, such that younger children required less force to occlude their airways. We tested 10 amber teething necklaces as per the standard set up described by American Society for Testing and Materials, substituting 1.6 pounds (0.73 kg) in place of the standard 15 pounds (6.80 kg). Eighty per cent failed to open at a force known to be sufficient to occlude a child’s airway. Though this test is much stricter than the published American standard it may be more clinically relevant.

In our sample of 15 amber teething necklaces, the type of clasp influenced whether the necklace would release when force was applied. In our sample, all of the necklaces with pop clasps released with 15 pounds of force. Only one of the eight necklaces with a screw clasp in our sample released at 15 pounds of force. These results may not be generalizable to all amber necklaces available for purchase as manufactures may have different specific clasp characteristics.

Limitations of this study include the small sample size of necklaces. Further, the sample does not represent the wide variety of necklaces that are available on the market. Nonetheless, even in the small sample tested, necklaces were unsafe. It is possible that a larger sample would identify more necklaces that are safe, but consumers have no way to tell which ones these are. If a small group of necklaces on the market instead of the majority did not meet standards, the strangulation risk posed by a few still outweighs any benefits. Another limitation of our study is that we measured only the force required to open the necklace as a measure of the potential for strangulation. Other factors contributing to strangulation risk might include the length of the chain, the mobility level of children wearing the necklaces or environmental factors.

Future research into the safety of children’s teething necklaces might include a larger sample of necklaces with a greater variety of necklace types. It might also include a process to collect cases of harm from necklaces and review these to determine factors associated with those cases as was done in the 1990s around blind cords and drawstrings on children’s clothing.

CONCLUSION

To our knowledge, this is the first study that quantitatively assesses the force required to release a sample of amber teething necklaces. Some retailers claim that necklaces are safe as they would open before strangulation could occur. However, in our study, we demonstrated that 8 of 10 failed to open at 1.6 pounds (0.73 kg) of force, and 8 of 15 necklaces required greater than 15 pounds (6.8 kg) of force to open. Contrary to claims made by some retailers, the necklaces do not break open easily or at forces less than that which could strangle a child.

Amber teething necklaces are a growing trend in North America and Europe with no scientific evidence to support their purposed analgesic mechanism; instead they may put children’s lives at risk. Physicians seeing children wearing these necklaces should inform parents about the strangulation risk and advise safer teething solutions.

What is Known on This Subject: Recommendations exist against the use of amber teething necklaces due to their potential strangulation/choking risk. One case report describes the non- fatal strangulation of a 5-month-old infant, while a media report describes the fatal strangulation of an 18-month old. There are no studies that test the purported analgesic mechanism of amber teething necklaces or evaluate their potential risks.

What This Study Adds: This is the first study that assesses the force required to open an amber necklace. The necklaces were tested using an industry standard (15 pounds), and using the mean force required to occlude a child’s airway reported (1.6 pounds).

Conflict of Interest

The authors have no conflicts of interest to disclose.

Author Contributions

LS conceptualized the design of this study and helped to carry out the analyses and data collection. LS drafted the initial manuscript. RM came up with the initial concept for this study and she contributed to the literature review. RM reviewed and revised the manuscript title and reviewed and revised the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.