Interpretation ID: 7293
Safeline Children's Products Co.
5335 W. 48th, Suite 300
Denver, CO 80212
Dear Mr. Dick:
This responds to your letter concerning Standard No. 213, "Child Restraint Systems," and the Sit'n'Stroll child restraint system you manufacture. The restraint is designed to be rear-facing for children weighing up to 25 pounds.
Your letter relates to our April 22, 1992 interpretation to Mr. Mark Sedlack regarding rear-facing restraints for children weighing up to 25 pounds. In that letter, I stated that under Standard No. 213, such a restraint could be tested with either the six-month-old or the three-year-old dummy in the agency's compliance tests. I further stated that the restraint must physically permit the dummies to be positioned in accordance with the procedures in S6.1.2.3.1 of Standard No. 213. If the restraint cannot permit the dummies to be so positioned, the restraint cannot be recommended for children weighing more than 20 pounds.
You ask whether we would consider the Sit'n'Stroll as permitting the proper positioning of the three-year-old dummy. The photographs enclosed with your letter show the dummy in the restraint with its legs at a right angle to the torso. The backs of the dummy's heels rest on the standard seat assembly's seat back, about five inches below the top of the seat back.
At the outset, I must note that NHTSA cannot provide you with an unqualified answer on whether your restraint accommodates the three-year-old dummy, because we do not know the details of your design. However, we can offer general guidance on the positioning of the dummy's legs, an aspect of the dummy's positioning that is of particular concern to you.
S6.1.2.3.1(b) and (d) of Standard No. 213 specify the procedure for positioning the three-year-old dummy's legs in the child restraint. S6.1.2.3.1(b) states: "... Extend the legs of the dummy as far as possible in the forward horizontal direction, with the dummy feet perpendicular to the centerline of the lower legs." S6.1.2.3.1(d) states: "...[R]otate each dummy limb downwards in the plane parallel to the dummy's midsagittal plane until the limb contacts a surface of the child restraint system or the standard seat .... Position the limbs, if necessary, so that limb placement does not inhibit torso or head movement in [the standard's dynamic] tests...."
Based on the photographs you enclosed, the Sit'n'Stroll permits the dummy's legs to be positioned as specified in S6.1.2.3.1(b). That is, the legs are extended "as far as possible" in the forward horizontal direction. The standard does not specify whether "forward" is relative to the standard seat assembly or to the child. However, interpreting "forward" as relative to the seat assembly would have the effect of disallowing the use of the three-year-old dummy to test a rear-facing restraint, since the positioning procedures would be inappropriate for the restraint. In the absence of language in the standard to that effect, we are disinclined to so conclude. Instead, we conclude "forward" as used in S6.1.2.3.1(b) is relative to the child.
Although the Sit'n'Stroll permits the legs to be positioned in accordance with S6.1.2.3.1(b), under S6.1.2.3.1(d) the leg placement must not inhibit torso or head movement during the dynamic tests of the standard. It does not appear that the dummy's legs would inhibit torso or head movement due to the forward (relative to the seat assembly) movement of the torso and head in the dynamic tests. However, we cannot make a definite determination based on the information in your letter.
Please note that it is likely that NHTSA will propose amending Standard No. 213 such that a child restraint designed for use with children weighing up to 25 pounds would be tested with a new array of child test dummies, such as the 9-month-old dummy described in subpart J of our regulations (49 CFR Part 572). It is possible that a future amendment to the standard could specify that a new dummy, such as the 9-month-old, will be used instead of the 3-year-old dummy to test such a child restraint. NHTSA has announced its intention to consider rulemaking on incorporating new dummies, including the 9- month-old, in Standard No. 213 compliance tests. This intention was discussed at length in NHTSA's "Planning Document on Potential Standard 213 Upgrade," July 1991.
I also would like to note our concern with the ability of your restraint to meet Standard No. 213's occupant excursion requirement (S5.1.3.2). S5.1.3.2 states: "In the case of each rear-facing child restraint system, [in a dynamic test] ... no portion of the target point on either side of the dummy's head shall pass through the transverse orthogonal planes whose intersection contains, the forward-most and top- most points on the child restraint system surfaces ...." It appears from your photograph that the restraint's seat back might be too low to enable the restraint to meet S5.1.3.2 in a dynamic test. One means of avoiding any potential compliance problem with the excursion requirement would be for your company to raise the height of the seat back on this child restraint system.
I hope this information is helpful.
Sincerely,
Paul Jackson Rice Chief Counsel
ref:213 d:8/18/92