ISO17712 2013 Security Seals

Friday 4 April 2014 11:47 AM

ISO 17712 2013 Setting New Standards for Security Seal Testing

ISO 17712 was launched back in 2010 as a direct result of the terrorist attack on the World Trade Centre twin towers. The U.S. Department of Homeland Security was tasked with thinking dark thoughts about alternative methods that could be employed to bring death and destruction to America’s shores and one way they imagined was the importation a bomb inside a sea container secured using one of a vast array of different mechanical freight container seals on the market.

The first step was to bring together all the recognised security seal manufacturers in the world to agree on a standard. The International Seal Manufacturers Association was already in place and that body bore the brunt of much of the work to define the elements of a barrier seal that made it secure and resistant to tampering. The next step was to ensure the security seal manufacturers themselves had business practices that were sufficiently secure, robust and fit for purpose.

The simplest way to define the robustness of a security seal is by its physical strength, so various mechanical tests were put in place at one U.S. testing house, Dayton T Brown, to test all seals submitted to determine the following four features:

Impact test: to determine the resistance to defined impact loads at a range of temperatures. This simulates someone taking a hammer to the seal.

Tensile test:  to define the force needed to overcome the locking mechanism and pull the bolt out of the bush or the cable back though the seal body.

Bending test: defines the resistance to failure under bending loads. This replicates someone attempting to bend the seal to create metal fatigue.

Shear test: determines the resistance to cutting with shearing blades, like those of a bolt or cable cutter

Today these tests can be carried out by other test laboratories which must comply with ISO/IEC 17025.

Unisto ISO17712:2013 Security Seal News

Other requirements:

Apart from these tests each security seal must be identified by unique marks:

Logo / Company Name

Unique serial number and optional barcode

The seal manufacturer’s identification marks, often blind embossed into the plastic or stamped into the metal.

Tested seals must show grade marks to indicate their classification. Most security seal manufacturers will not go to the cost and trouble to have their tamper evident security seals put through a battery of tests just to prove they have low resistance to these various forces. They already know which of their seals can be broken by hand and were designed for that purpose.  Should a seal manufacturer decide to test the lowest level seals will gain an “I” Indicative mark, to indicate they offer little physical strength. More resistant seals, requiring a pair of snips to remove them will be awarded an “S” Security mark.

Mostly it will be the high security barrier seals such as bolt or high specification cable seals that will be tested and marked with an “H” signifying High Security. Only manufacturers certified as compliant with Annex A, Security Related Practices are allowed to put grade marks on seals that have met the required standard for the classification level.

Seal Dimensions:

To take account of older freight containers that may have worn hasps, the standard specifies the minimum diameter of a bolt seal at its ends as 18mm. This amendment has been effective since March 2012.

Clause 6 (New clause effective from May 15th 2014)

Originally there was an intention to test seals against specific tamper-related criteria, however testing houses were unable to devise tests that would cope with the number of different seals on the market, and each designed to prevent or highlight tampering in different and diverse ways. In the end it was decided that security seal manufacturers should test for tamper resistance internally and those documented tests be independently audited as part of their standard ISO 9001 and ISO 17712 audit, in accordance with Normative Annex A.

Annex A – Security Seal Manufacturers’ Security Related Practice:

It is clear that a security manufacturer must have robust procedures and controls in place in order to be a reliable and secure provider of seals. For example it is vital that manufacturers’ premises are secure and that visitors are logged and escorted at all times.  Security seal manufacturers record the seal numbers of all seals dispatched to customers and keep those documented records for seven years, to provide customers or law enforcement organisations with the delivery address and names of customers and their employees that have purchased seals.

This system is tested regularly by customers, HMR&C and police; many years ago Unisto was able to provide evidence to police that brought about a conviction for murder by providing traceability on a batch of samples that had been sent to the murderer’s workplace and later turned-up at the crime-scene.


ISO 17712:2013 although a step forward is no substitute for vigilance. All security seals require management and control at every stage of their use. Seals need to be stored securely, issued responsibly, numbers recorded and checked at each stage. It is a wise precaution to photograph the seal in situ and e-mail the image ahead for the receiving depot to match (seals have been substituted in transit and the recipient none the wiser because they don’t know what they are looking for).

When removing a seal check it for signs of tampering first. Look for unusual marks or damage. Give the seal a tug, does it have its original strength or has it been glued or heat welded together? Once the seal is removed keep it with the consignment paperwork until all is reconciled and then dispose of the dead seal securely. Dead seals that have been removed and left on the ground or carelessly binned provide the opportunity to train tamperers and parts from spent seals can be used to create sham seals. Remember the security system they’ll be defeating could possibly be yours.

Finally, always ask your reputable barrier seal supplier for their current ISO 17712:2013 certificate, you can’t be too careful.


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