Do indicative Security Seals have to be tested according to the mechanical test described in ISO 17712?

We will explain why this is not necessary and even not requested by the ISO standard.



As defined in the official ISO17712 document (3.1.4. page 2)

Indicative seal are constructed and manufactured of material that can easily be broken by hand or by using a simple snipping tool or shear. They do not provide any barrier function like Security (S) or High Security (H) seals.

For this reason, the standard further mentions (5.1.1. NOTE, page 6):

The terms indicative, security, and high security refer to the barrier capabilities of a security seal (respectively, minimal, medium, and meaningful barrier strength).

Since indicative seals, by definition, ‘can easily be broken by hand’ (3.1.4), indicative seals do not need to be subjected to the strength tests in Clause 5.

Let us explain it with a simple example.

Based on the tensile strength test requirements, a seal to be classified as S (security seal) must achieve a value of 227 kg or higher during the test.

There is no commercially available plastic seal that comes even close to this value. An indicative seal could never reach that value. 

Why should something be tested if the result is already clear before the test begins?

Relevant topics for the indicative seals

The following topics, which are also part of the ISO17712 standard, seem much more important to us for indicative Security Seals. 

  • Evidence of Tampering – clause 6
  • Annex A - Seal manufacturers’ security-related practices
  • Requirements for the Manufacturer and Seals

Evidence of Tampering or Tamper resistance

This clause requires that seals be designed and built with tamper evidence features that provide obvious evidence of tampering (Clause 6, page 19).

The basic function of all seals is "indication ", i.e. the ability to provide evidence after an attempt has been made to tamper with the seal. In practical field applications this requires evidence that is susceptible to visual or other inspection of a seal in situ.   

Unisto has been designing and producing security seals for almost 100 years and the above-mentioned demand is part of our daily business.

In other words, long before the ISO17712 standard came into effect, it was always our aim to produce seals with the highest possible Tamper resistance.This is what we are known for by our customers

Annex A - Seal manufacturers’ security-related practices

This annex deals with and defines various topics such as Seal manufacturer certification, facility risk assessments and access controls to production and storage areas, distribution of seals, user knowledge and discipline, in-transit management, after-life (post-shipment stage in the life cycle of a seal),

As Unisto meets all the requirements of this Annex, we have been ISO 17712 Annex A certified since the very beginning. 

Requirements for the Manufacturer and Seals

The manufacturer:

  • must mark all seals with their company identity. If this is not visible on the seal, these seals are  not ISO17712 compliant
  • shall produce seals with unique numbers and identifiers e.g. customer logo
  • shall not re-use or duplicate these unique seal numbers
  • has to record by seal type the number and identification, the date of finishing production, the date
  • shall not re-use or duplicate these unique seal numbers
  • has to record by seal type the number and identification, the date of finishing production, the date    of the order,  date on which the seals were dispatched and to whom they were shipped
  • shall retain this information for a period of at least 7 years
  • shall control access to production and storage areas and loading docks and stores seals and related  devices in secure areas.
  • needs to be ISO 9001 certified.should be in possession of ISO 17712:2013 Annex A (Best Practices) certificate

 For indicative Security Seals, these are the relevant points.

 If you need more information or have any question, please do not hesitate to contact us!