Add-on child restraint system means any portable child restraint system.
Backless child restraint system means a child restraint, other than a belt-positioning seat, that consists of a seating platform that does not extend up to provide a cushion for the child's back or head and has a structural element designed to restrain forward motion of the child's torso in a forward impact.
Belt-positioning seat means a child restraint system that positions a child on a vehicle seat to improve the fit of a vehicle Type II belt system on the child and that lacks any component, such as a belt system or a structural element, designed to restrain forward movement of the child's torso in a forward impact.
Booster seat means either a backless child restraint system or a belt-positioning seat.
Built-in child restraint system means a child restraint system that is designed to be an integral part of and permanently installed in a motor vehicle.
Car bed means a child restraint system designed to restrain or position a child in the supine or prone position on a continuous flat surface.
Child restraint anchorage system is defined in S3 of FMVSS No. 225 (§ 571.225 ).
Child restraint system means any device, except Type I or Type II seat belts, designed for use in a motor vehicle or aircraft to restrain, seat, or position children who weigh 36 kilograms (kg) (80 lb) or less.
Contactable surface means any child restraint system surface (other than that of a belt, belt buckle, or belt adjustment hardware) that may contact any part of the head or torso of the appropriate test dummy, specified in S7, when a child restraint system is tested in accordance with S6.1.
Factory-installed built-in child restraint system means a built-in child restraint system that has been or will be permanently installed in a motor vehicle before that vehicle is certified as a completed or altered vehicle in accordance with part 567 of this chapter.
Harness means a combination pelvic and upper torso child restraint system that consists primarily of flexible material, such as straps, webbing or similar material, and that does not include a rigid seating structure for the child.
Rear-facing child restraint system means a child restraint system, except a car bed, that positions a child to face in the direction opposite to the normal direction of travel of the motor vehicle.
Representative aircraft passenger seat means either a Federal Aviation Administration approved production aircraft passenger seat or a simulated aircraft passenger seat conforming to Figure 6.
School bus child restraint system means an add-on child restraint system (including a harness) manufactured and sold only for use on school bus seats, that has a label conforming with S5.3.1(b). (This definition applies to child restraint systems manufactured on or after June 30, 2025.)
Seat orientation reference line or SORL means the horizontal line through Point Z as illustrated in Figure 1A.
Specific vehicle shell means the actual vehicle model part into which the built-in child restraint system is or is intended to be fabricated, including the complete surroundings of the built-in system. If the built-in child restraint system is or is intended to be fabricated as part of any seat other than a front seat, these surroundings include the back of the seat in front, the interior rear side door panels and trim, the floor pan, adjacent pillars (e.g., the B and C pillars), and the ceiling. If the built-in system is or is intended to be fabricated as part of the front seat, these surroundings include the dashboard, the steering mechanism and its associated trim hardware, any levers and knobs installed on the floor or on a console, the interior front side door panels and trim, the front seat, the floor pan, the A pillars and the ceiling.
Tether anchorage is defined in S3 of FMVSS No. 225 (§ 571.225 ).
Tether strap is defined in S3 of FMVSS No. 225 (§ 571.225 ).
Tether hook is defined in S3 of FMVSS No. 225 (§ 571.225 ).
Torso means the portion of the body of a seated anthropomorphic test dummy, excluding the thighs, that lies between the top of the child restraint system seating surface and the top of the shoulders of the test dummy.
Table to S5(f)-Average Weight of Child Represented by Various Test Dummies
Test dummy (specified in S7 of this standard) | Average weight of child represented by test dummy (pounds) |
CRABI 12-month-old infant dummy ( 49 CFR Part 572, Subpart R) | 22 |
Hybrid III 3-year-old dummy ( 49 CFR part 572, Subpart P) | 31 |
Hybrid III 6-year-old dummy 49 CFR Part 572, Subpart N) | 45 |
Hybrid III 6-year-old weighted child test dummy (49 CFR Part 572 Subpart S) | 62 |
Hybrid II 6-year-old dummy ( 49, CFR Part 572, Subpart I) | 45 |
shall not exceed 1,000, where a is the resultant acceleration expressed as a multiple of g (the acceleration of gravity), and t1 and t2 are any two moments during the impacts.
TABLE 1 TO S5.1.3.1(A)-ADD-ON CHILD RESTRAINTS THAT CAN BE USED FORWARD-FACING MANUFACTURED BEFORE JUNE 30, 2025
When this type of child restraint | Is tested in accordance with- | These excursion limits apply | Explanatory note: in the test specified in 2nd column, the child restraint is attached to the test seat assembly in the manner described below, subject to certain conditions |
Harnesses and restraints designed for use by children with physical disabilities | S6.1.2(a)(1)(i)(A) | Head 813 mm; Knee 915 mm | Attached with lap belt; in addition, if a tether is provided, it is attached. |
Harnesses labeled per S5.3.1(b)(i) through S5.3.1(b)(iii) and Figure 12 | S6.1.2(a)(1)(i)(A) | Head 813 mm; Knee 915 mm | Attached with seat back mount. |
Belt-positioning seats | S6.1.2(a)(1)(ii) | Head 813 mm; Knee 915 mm | Attached with lap and shoulder belt; no tether is attached. |
All other child restraints (i.e., other than harnesses, restraints designed for use by children with physical disabilities, harnesses manufactured exclusively for school buses, and belt-positioning seats) | S6.1.2(a)(1)(i)(B) | Head 813 mm; Knee 915 mm | Attached with a lap belt, without a tether attached; and, Attached to lower anchorages of a child restraint anchorage system; no tether is attached. |
All other child restraints (i.e., other than harnesses, restraints designed for use by children with physical disabilities, harnesses labeled per S5.3.1(b)(i) through S5.3.1(b)(iii) and Figure 12, and belt-positioning seats) | S6.1.2(a)(1)(i)(A), S6.1.2(a)(1)(i)(C) | Head 720 mm; Knee 915 mm | Attached with a lap belt, with a tether attached; and, Attached to lower anchorages of child restraint anchorage system, with a tether attached. |
TABLE 2 TO S5.1.3.1(A)-ADD-ON CHILD RESTRAINTS THAT CAN BE USED FORWARD-FACING MANUFACTURED AFTER JUNE 30, 2025
When this type of child restraint | Is tested in accordance with- | These excursion limits apply | Explanatory note: in the test specified in 2nd column, the excursion requirement must be met when the child restraint system is attached to the test seat assembly in the manner described below, subject to certain conditions |
Harnesses and restraints designed for use by children with physical disabilities | S6.1.2(a)(1)(i)(A) | Head 813 mm; Knee 915 mm | Attached with lap and shoulder belt; in addition, if a tether is provided, it is attached. |
School bus child restraint systems | S6.1.2(a)(1)(i)(A) | Head 813 mm; Knee 915 mm | Attached with seat back mount, or, seat back, and, seat pan mounts. |
Booster seats | S6.1.2(a)(1)(ii) | Head 813 mm; Knee 915 mm | Attached with lap and shoulder belt; no tether is attached. |
Child restraints other than harnesses, restraints designed for use by children with physical disabilities, school bus child restraint systems, and booster seats | S6.1.2(a)(1)(i)(B) | Head 813 mm; Knee 915 mm | Attached with a lap belt; without a tether attached. Attached to lower anchorages of child restraint anchorage system; with no tether attached. |
Child restraints other than harnesses, restraints designed for use by children with physical disabilities, and school bus child restraint systems | S6.1.2(a)(1)(i)(A), S6.1.2(a)(1)(i)(C) | Head 720 mm; Knee 915 mm | Attached with a lap belt, with a tether attached. Attached to lower anchorages of child restraint anchorage system, with a tether attached. |
Child restraints equipped with a fixed or movable surface described in S5.2.2.2 that has belts that are not an integral part of that fixed or movable surface | S6.1.2(a)(2) | Head 813 mm; Knee 915 mm | Attached with lap belt, no tether is attached. |
Table to S5.2.1.1(a)
Weight1 | Height2(mm) |
Not more than 18 kg | 500 |
More than 18 kg | 560 |
1 When a child restraint system is recommended under S5.5 for use by children of the above weights.
2 The height of the portion of the system seat back providing head restraint shall not be less than the above.
Table for S5.3.2
Type of add-on child restraint system | Means of installation | ||||
Type 1 seat belt assembly | Type 1 seat belt assembly plus a tether anchorage, if needed | Child restraint anchorage system (effective September 1, 2002) | Type II seat belt assembly | Seat back mount | |
Harnesses labeled per S5.3.1(b)(1) through S5.3.1(b)(3) and Figure 12 | X | ||||
Other harnesses | X | ||||
Car beds | X | ||||
Rear-facing restraints | X | X | |||
Belt-positioning seats | X | ||||
All other child restraints | X | X | X |
Table to S5.5.2(l)(3)(i)(B)-Maximum Child Weight Limit for Lower Anchor Use for Forward-Facing Child Restraint System-Rounding
CW = 65-child restaint weight (pounds) | Child weight limit "*" (pounds) |
20 [LESS THAN] CW [LESS THAN EQUAL TO] 25 | 25 |
25 [LESS THAN] CW [LESS THAN EQUAL TO] 30 | 30 |
30 [LESS THAN] CW [LESS THAN EQUAL TO] 35 | 35 |
35 [LESS THAN] CW [LESS THAN EQUAL TO] 40 | 40 |
40 [LESS THAN] CW [LESS THAN EQUAL TO] 45 | 45 |
45 [LESS THAN] CW [LESS THAN EQUAL TO] 50 | 50 |
50 [LESS THAN] CW [LESS THAN EQUAL TO] 55 | 55 |
55 [LESS THAN] CW [LESS THAN EQUAL TO] 60 | 60 |
Table to S5.5.2(l)(3)(i)(C)-Maximum Child Weight Limit for Lower Anchor Use for Rear-Facing Child Restraint System-Rounding
CW = 60-child restraint weight (pounds) | Child weight limit "*" (pounds) |
15 [LESS THAN] CW [LESS THAN EQUAL TO] 20 | 20 |
20 [LESS THAN] CW [LESS THAN EQUAL TO] 25 | 25 |
25 [LESS THAN] CW [LESS THAN EQUAL TO] 30 | 30 |
30 [LESS THAN] CW [LESS THAN EQUAL TO] 35 | 35 |
35 [LESS THAN] CW [LESS THAN EQUAL TO] 40 | 40 |
40 [LESS THAN] CW [LESS THAN EQUAL TO] 45 | 45 |
45 [LESS THAN] CW [LESS THAN EQUAL TO] 50 | 50 |
50 [LESS THAN] CW [LESS THAN EQUAL TO] 55 | 55 |
The test conditions described in S6.1.1 apply to the dynamic systems test. The test procedure for the dynamic systems test is specified in S6.1.2. The test dummy specified in S7 is placed in the test specimen (child restraint), clothed as described in S9 and positioned according to S10.
The belt assembly buckles used in any child restraint system shall be tested in accordance with S6.2.1 through S6.2.4 inclusive.
Figure 9a-2 to § 571.213
Figure 9b-2 to § 571.213
49 C.F.R. §571.213
For FEDERAL REGISTER citations affecting § 571.213, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov.