Erika Z. Jones
Mayer Brown LLP
1999 K St., N.W.
Washington, DC 20006-1101
Dear Ms. Jones:
This responds to your November 29, 2012 letter to the National Highway Traffic Safety Administration (NHTSA) on behalf of Graco Children’s Products, Inc. (Graco), asking about Federal Motor Vehicle Safety Standard (FMVSS) No. 213, Child restraint systems. On
January 8, 2013, you and Graco representatives met with NHTSA staff to elaborate on the information provided in your letter.
Your questions relate to a Graco belt-positioning booster seat that has armrests that are height-adjustable so that a caregiver can lower or raise the armrests to a height comfortable for the child. You note Graco has observed that, in some tests, an armrest separated from the booster seat. In other tests, the armrest did not separate, but moved from a lower adjustment position to a higher adjustment position, remaining level. You state that the injury assessment reference values measured by the test dummy used in the tests were all within the limits of FMVSS
You ask about S5.1.1(a) and (b)(1) of FMVSS No. 213, which state:
S5.1.1 Child restraint system integrity. When tested in accordance with S6.1, each child restraint system shall meet the requirements of paragraphs (a) through (c) of this section.
(a) Exhibit no complete separation of any load bearing structural element and no partial separation exposing either surfaces with a radius of less than ¼ inch or surfaces with protrusions greater than 3/8 inch above the immediate adjacent surrounding contactable surface of any structural element of the system.
(b)(1) If adjustable to different positions, remain in the same adjustment position during the testing that it was in immediately before the testing, except as otherwise specified in paragraph (b)(2). [Paragraphs (b)(2) and (c) are not relevant to Graco’s question so we do not restate them here.]
* * * * *
The following interpretation of FMVSS No. 213 is based on our understanding of the information provided in your letter and in the meeting, and is limited to the particular aspects of the Graco booster seat you presented.
Question 1. Your first question asks: does S5.1.1(a) prohibit the armrest separating from the booster seat?
Our answer is no, we do not consider the armrest separation to be prohibited by S5.1.1(a). This is because the “complete separation” prohibition of S5.1.1(a) applies to “load bearing structural element(s),” and it does not appear that the armrests qualify as such.
Your letter states that the armrests are provided “for the child’s comfort and to provide a visual guide for the pre-crash positioning of the vehicle’s Type II belt system.” (The owner’s manual Graco provided (on pages 29 and 35) states: “The lap belt portion MUST pass under the armrests and be positioned low on the hips…” (Emphasis in text.) We assume this is what was meant by your statement that the armrests provide “a visual guide.”) Graco also indicated in the meeting that the armrests do not contribute to the crashworthiness of the seat.
We have determined that the armrests are not load-bearing structural elements. We interpret the term “load-bearing structural element” as referring to parts of the child restraint system (CRS) that are needed for the CRS to function as a child restraint and to meet FMVSS No. 213. You indicate that the armrest is provided for comfort and moved due to the Type II belt buckle pushing against it. It does not appear to us that the armrest is needed for the CRS to function as a child restraint or that it contributed to the child restraint’s meeting the standard. Thus, we conclude that the armrest is not a load-bearing structural element subject to the “complete separation” prohibition of S5.1.1(a).
Question 2. Your next question asks whether an armrest is required by S5.1.1(b)(1) to remain in the same adjustment position during the testing that it was in immediately before the testing.
Our answer has two parts.
First, S5.1.1(b)(1) generally applies to adjustable armrests. The requirement is intended to prevent a child’s fingers or limbs from being caught between shifting parts of the child restraint, and to prevent a child from sliding too far forward and downward (submarining) during a crash. A change in adjustment position of an armrest could pose an unreasonable injury risk by collapsing on a child’s limb or fingers or by movement that results in a scissoring action, the closure of apertures in which a finger can be caught, etc.
However, we have in the past interpreted S5.1.1(b)(1) as not applying to certain mechanisms. In one letter, we interpreted S5.1.1(b)(1) as not applying to an adjustable shoulder belt clip that moved from an initial adjustment position in FMVSS No. 213’s
dynamic test. In another letter, we did not apply S5.1.1(b)(1) to a headrest’s moving
upward. With those mechanisms, the change in adjustment position would not increase the risk of finger or limb entrapment or increase the risk of submarining.
Thus, our second part to the answer is that we interpret S5.1.1(b)(1) as not prohibiting the armrest’s change in adjustment position from a lower height to a higher height. That change of position of the armrest would not result in an increased risk of finger or limb entrapment, unlike the case of an armrest that shifted to a lower adjustment position from a higher one. Also, the armrest’s change of adjustment position would not increase the risk of submarining. We assume in this answer that there is not associated with the change in armrest position any kind of scissoring mechanism between shifting parts to which the child would be exposed, no apertures that become smaller, no increased concentration of forces on the child, etc.
If you have further questions, please do not hesitate to contact us.
O. Kevin Vincent
Ref: Standard No. 213
 Graco indicated that the armrest moved upward basically because the Type II belt buckle was positioned under the armrest at the beginning of the test. In the dynamic test, the armrest sometimes moved to the higher adjustment position because the belt imposed a force (from the belted test dummy) upwards on the armrest.