UN R17 Supplement 1 (10 series) · UNECE Regulation No. 17 (ECE R17) — Uniform provisions concerning the approval of vehicles with regard to the seats, their anchorages and any head restraints.
UN R17 — Supplement 1 to the 10 series of amendments
Base text → Supplement 1
- What changed
- In the definition of “Head restraint”, the words “at any point” are now “at at least one point”.
- Several head restraint provisions now use the longitudinal vertical plane passing through the R-point instead of the torso line or the reference line.
- In Annex 6, paragraph 1.4.2.1. now gives the direction of impact for the rear face, not for the front face.
- Why
- The word “any” in the definition of “Head restraint” gave another meaning than intended.
- CLEPA proposed to replace the torso line in the test procedures to harmonize the set-ups of all tests.
- The expert from France proposed to correct Annex 6, which was not correctly updated, and inconsistent or unclear text in Annexes 8 and 11.
Q1What changed24 changes
Definition of “Head restraint” and the plane through the R-point (paras. 2.13., 5.5.1.2. and 5.6.3., Annexes 4 and 12)
In the definition of “Head restraint” (para. 2.13.), the words “at any point” are now “at at least one point”. The two planes are now 85 mm on either side of the longitudinal vertical plane passing through the R-point, not of the torso line. Paragraph 5.6.3. and Annex 4, paragraph 2.4., now use the longitudinal vertical plane passing through the R-point for the distances L and L'. At the end of paragraph 5.5.1.2., “reference line” is now “longitudinal vertical plane passing through the R-point”. Figure 4-1 of Annex 4 is amended, and its labels include the longitudinal vertical plane passing through the R-point. In Annex 12, paragraph 3.3.2., the lateral distance of 70 mm is now from the “longitudinal vertical plane passing through the R-point centreline”.
Gap measurement in Annex 8 (para. 2.3. and notes under Figures 8-1 and 8-2)
In Annex 8, paragraph 2.3. now says that the area of measurement is on the front face of the head restraint. The two planes are now 85 mm on either side of the longitudinal vertical plane passing through the R-point, not of the torso line. The notes under Figures 8-1 and 8-2 no longer say “without exerting any load”.
Rear face of the head restraint (para. 5.5.2., Annex 6, paras. 1.4.2.1. and 1.4.2.2.)
Paragraph 5.5.2. now names the energy dissipation test, not the energy absorption test, for parts of rear faces of head restraints in area 1. In Annex 6, paragraph 1.4.2.1. now gives the direction of impact for the rear face. The impact is from the rear towards the front, in a longitudinal plane at an angle of 45° from the vertical. Before, this paragraph gave a horizontal direction of impact from the front towards the rear, for the front face. Paragraph 1.4.2.2. now covers only the rear zones and refers to figure 10-4 instead of paragraph 6.5.
Test headings and references (paras. 5.2.2., 6.4. and 6.4.3., Annex 15, para. 5.1.)
Paragraph 6.4. now has the heading “Displacement and strength test of head restraint”. Before, the heading was “Test of the performance of the head restraint”. Paragraph 6.4.3. now says that Annex 5 describes the test for rearward displacement and for strength of the head restraint and its anchorages. Paragraph 5.2.2. now refers to paragraph 2.8. instead of 2.7. Annex 15, paragraph 5.1., now refers to paragraph 5.6.2. instead of 5.6.1.
Backset measurement in Annex 11 (paras. 2. to 2.5.)
In Annex 11, the text of paragraph 2. no longer has the words “and for its dimensions is based on Figure 10-2 of Annex 10”. Paragraph 2. now also says that the H-Point machine itself is not placed on the seat during this measurement. Paragraph 2.1. now also requires the seat back to be adjusted to its design angle, and old paragraph 2.2. with this step is deleted. Paragraphs 2.3. to 2.6. are renumbered as 2.2. to 2.5. Paragraph 2.5. now also says that all measurements must be taken in the longitudinal vertical plane passing through the R-point.
Q2Why it changed
- Proposed by
- Experts from France and CLEPA
- Working party
- GRSP, 78th session (December 2025)
Reasons
The word “any” in the definition of “Head restraint” gave another meaning than intended. So it was proposed to align the definition with a principle from the creation of UN Global Technical Regulation No. 7. This principle looks at seat trim within ±85 mm of a longitudinal median plane of the seat. If the trim is over 700 mm high at at least one point there, it should be considered that a head restraint is present.
Sources (2)
“The definition of head restraint and the wording ‘any’ gave another meaning than intended and it is therefore proposed to align to the principle explained”
“in the case that seat trim is present at a height over 700 mm at at least one point within +/- 85 mm from a longitudinal median plane of the seat”
Since the 10 series of amendments, some test procedures have referred to the torso line. Most have referred to the median longitudinal plane of the seat or to the reference line. To harmonize the set-ups of all tests, it was proposed to replace “torso line” in the test procedures.
Sources (2)
“Since the 10 series of amendments, some test procedures are referenced to the torso line whereas the majority is referenced to the median longitudinal plane of the seat or to the reference line”
“In order to harmonize the set ups of all tests we propose to substitute the wording torso line in test procedures”
Since the 10 series of amendments, Annex 6 covers the energy dissipation test for the rear part of the head restraint. Annex 12 covers the energy absorption test for the front. But Annex 6 was not correctly updated, and references to the front part of the head restraint remained. The proposal aims to correct this annex.
Sources (2)
“Annex 6 covers the test procedure for checking energy dissipation on the head restraint for the rear part and Annex 12 is covers the energy absorption test procedure for head restraint from the front”
“However, Annex 6 was not correctly updated and references to the front part of the head restraint remain. This proposal aims at correcting this annex.”
In Annex 8, Figures 8-1 and 8-2 asked for the measurement without exerting any load. But paragraph 2.4. asks for a load of no more than 5 N against the area of measurement. The proposal aims to correct this inconsistency. The 09 series of amendments asked for the gap to be measured from the front face of the head restraint. This wording was lost in the 10 series, so it was proposed to put it back for more clarity.
Sources (2)
“Figure 8-1 and Figure 8-2 requests to make the measure without exerting any load, whereas paragraph 2.4 requests “Applying a load of no more than 5 N against the area of measurement”, which leads to an inconsistency”
“But this wording has disappeared between the 09 and 10 series of amendments to this regulation. We propose to reintegrate this information in the test procedure for more clarity.”
In Annex 11, the words “and for its dimensions is based on Figure 10-2 of Annex 10” in paragraph 2. were not clear. Figure 10-2 is about effective height, so the proposal aims to remove these words to clarify the test. Annex 11 also asked for the seat back to be adjusted to its design angle after the actual torso angle was evaluated. To correct this inconsistency, the proposal asks to adjust the seat back to its design angle before the torso angle is checked.
Sources (2)
“which is not clear concerning the dimensions, because figure 10-2 corresponds to effective height”
“The proposal aims at correcting this inconsistency, by requesting to adjust the seat back to its design angle before checking the torso angle”
Document trail
- 2025-09ProposalECE/TRANS/WP.29/GRSP/2025/27Proposal by the expert from France
- 2025-09ProposalECE/TRANS/WP.29/GRSP/2025/44Proposal by CLEPA for the 12 series of amendments
- —Amended in sessionGRSP-78-13-Rev.1France and CLEPA changes to both proposals, for the 10, 11 and 12 series
- —Working party adoptsECE/TRANS/WP.29/GRSP/78GRSP adoption at its 78th session (para. 19 and Annex IV.A)
- 2026-03Sent to WP.29ECE/TRANS/WP.29/2026/47Text that GRSP sent to WP.29 and AC.1
- 2026-06-24WP.29 adoptsECE/TRANS/WP.29/1192Adopted at the 199th session (session report, para. 103)
- PendingIn forceDate not yet known
Q3Who is affected
Vehicle manufacturer
- Check your seat designs against the amended definition of “Head restraint” in paragraph 2.13.
- Check the 85 mm minimum head restraint width on either side of the longitudinal vertical plane passing through the R-point.
Component supplier
- Give the vehicle manufacturer head restraint widths measured from the longitudinal vertical plane passing through the R-point.
Technical service / Approval authority
- In Annex 4, paragraph 2.4., measure the distances L and L' from the longitudinal vertical plane passing through the R-point.
- In Annex 8, take the area of measurement on the front face of the head restraint (paragraph 2.3.).
- Update your Annex 8 gap measurement instructions: the figure notes no longer say “without exerting any load”.
- Update your Annex 6 rear face test to the impact direction in paragraph 1.4.2.1.
- In Annex 11, adjust the seat back to its design angle as part of paragraph 2.1.
- Make sure that your Annex 11 backset measurements are all in the longitudinal vertical plane passing through the R-point.
- In Annex 12, measure the 70 mm lateral distance from the plane given in paragraph 3.3.2.
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ⓘ This report gives advice only. It is not legal or type-approval advice.