The 1958 Agreement is one of the three agreements administered by the UN World Forum for Harmonization of Vehicle Regulations (WP.29) serviced by the UNECE Sustainable Transport Division. The 1958 Agreement provides the legal and administrative framework for establishing international UN Regulations (annexed to the Agreement) with uniform performance oriented test provisions and administrative procedures for granting type approvals. The Regulations also cover the conformity of production and the mutual recognition of the type approvals granted by Contracting Parties.
All UN countries can join WP.29 and become Contracting Parties to the UN 1958 Agreement. Contracting Parties can apply the UN Regulations at the national level and propose amendments by participating in the discussions. Through the discussions countries have the opportunity to have their local needs reflected in the international Regulation requirements. UN Regulation No. 22 on helmets is only one of the 152 UN Regulations annexed to the 1958 Agreement currently in force. The regulation is supervised and updated by the Working Party for Passive Safety (GRSP), which is one of the subsidiary Working Parties to WP.29.
Harmonized regulations allow the benefits of economies of scale and the resulting spread of new technologies to accrue to a greater number of riders. UN Regulation No. 22 was adopted in response to the need to harmonize different national technical provisions on helmet design and testing. Since its adoption in 1972, UN Regulation No. 22 has been updated to reflect new scientific developments.
The original version of UN Regulation No. 22 (from 1972) contained General requirements that addressed the coverage of the head and ensured an adequate field of vision and adequate hearing for the user, provided for the possibility of ventilation holes, minimized projections (which may get caught when the helmet slides over a surface and thus increase the rate of rotation), and ensured the durability of materials used. The requirements at the time also stipulated a maximum helmet mass of 1 kg. Conditioning procedures included cold, heat and moisture treatments, which replicated typical conditions of use. Furthermore a series of tests, and head-form sizes for their administration, were prescribed to replicate adverse conditions upon which the helmet needs to perform its protective role.
- A shock absorption test replicating an impact to the head;
- A penetration test designed to replicate puncturing of the helmet;
- A rigidity test of the helmet when compressed longitudinally and then laterally;
- A test for chinstrap deformation and a test for its tearing;
- Tests for peak flexibility and non-flammability.