News

Weight Limit Labels a Step Forward for LATCH

This article originated in the March/April 2014 issue of Safe Ride News.

Clippy Walking

This issue of SRN celebrates the amendments to FMVSS 213 that went into full effect on February 27, 2014, expanding the standard’s scope to include CRs for children up to 80 pounds (formerly 65 pounds).   Although the purpose of this expansion, when first directed by Congress over 10 years ago, was to bring most boosters under FMVSS 213, the effect is to also ensure that today’s wide array of CRs with very high-weight harnesses will be tested according to the standard’s requirements.

However, due to concerns about anchor strength and heavier children riding in heavier CRs, NHTSA does not require testing of CRs installed using the lower attachment system at all weights covered by the standard.  Specifically, testing with lower attachments is not required if the weight of the CR plus the dummy (technically, the average child weight represented by the dummy) exceeds 65 pounds.  This situation spurred the need for the much-discussed lower-anchor weight limit labels, which will now appear on all convertible and combination CRs produced for the U.S. market.

I want to be clear that SRN celebrates these labels, right along with the other parts of the amendment.  While it’s true that we participated in the petition for NHTSA to reconsider certain aspects of them, having a single source of lower anchorage weight limit information—and that source being a clear label on the CR—was never the cause for our concern. The aspects we did question were each addressed in the final rule for FMVSS 213 released on February 20, just a week before the compliance deadline.

NHTSA responded to our primary concern—that a maximum of 65 pounds seems too low as a combined weight of CR plus child—by supplying the results of some recent testing.  Those tests led to the conclusion that anchor failure could occur in certain situations in current vehicles, although many vehicle LATCH systems seem to be designed to be much stronger than required.

An example of a worst-case scenario was found by a Transport Canada study that crash-tested 32 high-weight-harness CRs in real vehicles. The only lower-anchor failure involved a Safety 1st Apex 65 with the 10-year-old dummy (77 pounds) installed with lower anchors and tether in a 2010 Kia Forte. NHTSA then arranged for FMVSS 225-type, quasi-static testing of anchors in other vehicles that have relatively high peak accelerations in a 30-35 mph crash. (Test details have been posted at www.regulations.gov in Docket # NHTSA-2014-0026).

NHTSA also expressed concern regarding the public’s continuing low usage rate of tethers along with the lower anchors.  In a separate study, it found that loads on the lower anchors increased by 30 to 60 percent when a tether isn’t also used.

Based on these considerations, NHTSA found that the 65-pound combined weight maximum was the most prudent limit to cover all potential situations. NHTSA also confirmed that some of its past documents contained errors by indicating that the 65-pound maximum included only the child’s weight, a source of ongoing confusion. Therefore, NHTSA’s response closes the book on the debate regarding the historical intention of FMVSS 225: although that standard doesn’t directly relate LATCH anchor strength to any particular weight, the minimum required strength is meant to translate to a combined CR and child weight of 65 pounds.

By sharing its anchor strength analysis, NHTSA addresses the petitioners’ concern that LATCH anchors, in their current form, were being limited to an overly conservative maximum weight.  Of course, this doesn’t change the fact that we would like to see LATCH safe for use at higher weights, but that is a matter for future discussions and analysis.  For now, we can be happy knowing that we’ve taken a major step forward with LATCH by adding a standardized label that clearly and consistently tells the child weight limit for using the lower attachment system.

One other point about the weight limit labels is very important to understand: they take into account vehicle manufacturer, CR manufacturer, and NHTSA considerations.  Therefore, when working with CRs displaying the new labels, one can rest assured that the label is the only source of lower-attachment weight limit information that needs to be consulted.  On CRs with the label, we no longer have to look up two sources (vehicle and CR), determine how to compare them, call customer service centers, or bemoan a lack of clarity.  When precompliance CRs that don’t display the label have all expired (in six to 10 years), the transition will mark a major improvement in ease of use.

Summary of Modifications to FMVSS 213 Amendment

These label-related changes to the FMVSS 213 final rule were introduced in the February 2014 response to petitioners. Find full details at www.regulations.gov in Docket # NHTSA-2014-0026.

Rounding Up or Down: NHTSA acknowledged petitioners’ concerns that the variability of weight limits among CR models would be confusing to consumers.  It compromised by allowing rounding to weights ending in 5 or 0.  Based on its testing, NHTSA stated that for FF CRs, manufacturers can safely round up (allowing a combined weight that is higher than 65 by as much as 4 pounds).  However, in the few cases in which lower attachments are limited during RF use (none of which are RF-only models), NHTSA ruled that it would not be prudent to round up, and therefore it allows only rounding down for these CRs.

Unfortunately, this permission to round up came too late for the first batch of CRs with the compliant labels.  Although many do display limits that are rounded, manufacturers assumed they would need to round down.  Since manufacturers might later opt to take advantage of permission to round up, it is important to always check the labels, rather than try to memorize them.

Label Placement: NHTSA’s response also introduced a new requirement for the placement of labels.  Instead of simply requiring standardized text, NHTSA further instructed manufacturers to place the LATCH weight limit information with the already-required diagram showing LATCH use (see example below).  The compliance deadline for this new aspect of the rule is February 27, 2015, with optional early compliance.  For CPSTs, this means that determining whether a CR has the LATCH weight limit label will involve looking in two places for the next several years.

Denise Donaldson—Denise Donaldson