Pulling or “Tug Testing” Baby Carriers
It has recently come to the attention of the BCIA that people have been “tug testing” their carriers and/or recommending to others that this is a way to “test” your carrier’s construction at home. The BCIA consulted with 2 industrial engineers, a US testing lab representative, a UK consumer product safety consultant and a number of baby carrier manufacturers and asked for their expertise on this subject.
Before using your carrier:
Visually inspect your carriers regularly for signs of wear, tears, and loose stitching. Inspect all hardware for signs of cracks or breakage. Our manufacturer members suggest a tactile inspection as well: when you run your fingers over the seams and stitching, you will feel loose or damaged areas if they exist. If there is any sign of ripping, tearing or popped stitches, stop using your carrier and contact the manufacturer. Do not “test” the carrier yourself, as doing so could damage the carrier further and possibly void any warranty. Please give manufacturers time to respond to your inquiry.
Should I pull on the straps to test my carrier?
ASTM testing standards for carriers are rigorous and designed for a carrier’s intended use. This testing is not meant to be replicated at home by pulling, twisting or tugging on a carrier’s seams or straps. Pulling the straps at an angle from the body of the carrier can cause undue stress, as it is a concentrated force. This method of “testing” does not replicate the way a carrier is meant to be used, where the child’s weight is evenly distributed across the seat of the carrier and along the shoulder straps.
The industry experts consulted are in agreement that one of the pivotal problems with “tug testing” or pulling on the straps of a carrier is that there is no way to measure the force of a pull: “The potential variation of the maximum applied force between different ‘testers’ could vary as much as a factor of 3.” That is to say, an adult sustained pull can range from 30-90 pounds, and an instantaneous jerk can measure even higher. When this stress is applied directly to a few stitches, it will weaken them, if not cause them to give way. Testing in this manner is destructive. While the ASTM does conduct destructive tests, those carriers are not considered fit for sale afterwards. That is why a sample is sent. Consumers who wish to sell their carriers in the used market should ethically disclose if they have done their own testing on the carrier.
Can I test my carrier at home aside from doing a visual inspection?
Our industry engineers suggest that if consumers are making their own carriers, or using other homemade carriers, and are concerned about the strength of the carrier, they could consider testing the carrier by wearing it with a 50 pound weight in it. While this is not as thorough as the ASTM testing, it may offer a somewhat similar examination and should expose any serious and immediate concerns. It is important to note that the ASTM testing is done with the carrier in usage on a torso, which replicates the way a carrier is meant to be used. Testing a carrier on a torso (or while wearing it) ensures that the stresses to the carrier are placed in the proper direction.
I want to know that my carrier is secure. What else can I do?
Consumers who are concerned about the safety of their carriers should seek to purchase carriers that have been tested to ASTM standards. If your favorite small brand has not yet been tested, contact the manufacturer and strongly encourage them to do the testing as soon as possible.
Consumers should be conscious of the age of their carriers. All fabrics will wear over time and with active use. Signs of excess wear can be determined by a visual and tactile inspection of seams and hardware.
For interested or concerned parties who wish to obtain more information about the standardized testing procedure the ASTM standards can be purchased for $40 USD (search for standards ASTMF2236 for soft infant carriers, including SSCs, front packs, and mei tais, and ASTMF2907 for sling carriers, including wraps). The standards outline the testing procedures in detail. If there is still concern that the standard tests are not adequate then this matter should be addressed through the appropriate standards committees. The BCIA works closely with the ASTM and CPSC to ensure product safety in the baby carrier industry. Questions and concerns can be directed to firstname.lastname@example.org