High Security Seals and ISO 17712 Explained

  • High Security Seals and ISO 17712 Explained

    High Security Seals and ISO 17712 Explained

    There is a growing number of businesses offering security seal services around the world. These businesses offer a wide range of security seals, security bags, security labels and security tapes. Each of these of ranges is segmented in to sub-categories. For security seals this means sub-categories for ‘High Security Seals, Indicative Seals, Plastic Security Seals and more. We will be looking at the High Security Seals sub-category as these security seals are the crème de la crème range in the industry. Not all security seal manufacturers can supply you with these types of seals. Do you know what ISO 17712 is? Scroll down to find out more…


    ISO (International Organization for Standardization) is the world’s largest developer of voluntary International Standards. A standard is a document that provides requirements, specifications, guidelines or characteristics that can be used consistently to ensure that materials, products, processes and services are fit for their purpose. ISO International Standards ensure that products and services are safe, reliable, and of good quality.


    ISO 17712 is the standardised document that establishes “uniform procedures for the classification, acceptance, and withdrawal of mechanical freight container seals. It provides a single source of information on mechanical seals which are acceptable for securing freight containers in international commerce.”

    ISO 17712 defines three types of classes of security seal strength, or barrier capacity: “I” for Indicative; “S” for Security; and “H” for High Security. C-TPAT requires the use of “H” class seals. Suppliers must use independent third party test laboratories to validate a security seal’s classification. The test laboratory must also be accredited according to ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories) to perform testing specific to ISO 17712.

    The ISO 17712 standard requires independent testing against three main categories:

    1. Mechanical Testing to determine a security seals physical strength (Clause 5).

    “H” Class Security Seals or High Security Seals are manufactured to the highest standards and are marked with a “H” on the seals body. The most popular high security seals are bolt seals and cable seals.

    In May 2014, new requirements were published for ISO 17712:2013, for all security seals to be compliant, they must be categorized and marked “H” as High Security Seals. When undergoing mechanical testing by an independent ISO 17025 accredited laboratory (Clause 5) and the manufacturer must be certified to both ISO9001 and ISO17712: Annex A.

    1. Seals be designed and constructed with tamper indicative features that generate tell-tale evidence of tampering (Clause 6).

    The new requirement for High Security Seals also states that the security seal must also be compliant with Clause 6: Evidence of Tampering. Clause 6 requires the manufacturer to have a documented and audited process and test specification in place in its quality manual for all High Security Seals in its product range. Clause 6 is a valuable addition to the seal standard emphasizing the importance of continuous improvement of tamper resistance and tamper indicating features on security seals.

    If a High Security Seal is only presented to you with a clause 5 certificate or just a clause 6 certificate then it does not have the “H” classification, which means it is not a High Security Seal.

    The following products are “H” class Security Seals: 2K Klicker, MCLZ, and Bar Seal.

    3.  Auditing of manufacturer’s security-related business processes (Annex A)

    Poor security-related manufacturing practices can undercut the effectiveness of a high-quality security seal. ISO 17712’s Annex A defines over two dozen required practices, such as facility risk assessments and access controls to production and storage areas. Suppliers’ conformance with Annex A should also be demonstrated through an independent certification provider that is accredited to audit compliance with the ISO standards.

    In order to verify that a High Security Seal is certified as ISO 17712:2013, You must contact your security seal supplier and ask them to provide the ISO certificates mentioned below:

    • The manufacturer of the seal has to be ISO 9001 certified.
    • The manufacturer of the seal has to be ISO 17712:2013 Annex A (Best Practices) certified.
    • The mechanical strength of the seal has to meet or exceed the requirements of ISO 17712 Clause 5 High Security Seal category. This is documented by a ISO 17712:2013 “H” laboratory report / certificate for the seal.
    • ISO17712: 2013 Clause 6 Tamper Evidence Compliance Letter
    • The test laboratory performing the strength tests must be ISO 17025 accredited to perform ALL 5 mechanical tests according to ISO 17712:2013 Clause 5.
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