There are two types of security seal: indicative security seals, and barrier seals. These categories are further broken down within the ISO-17712 standards, which name three specific classifications.
Indicative security seals
These seals are easily broken, or able to be opened with light tools. They’re often used as tamper evidence, and as such are sometimes also known as tamper-evident seals.
Barrier seals
Barrier seals are the stronger level of seals, designed to require higher strength, or bigger tools, to open. These are broken down into two classifications: security seals, and high security seals.
Security seals
These provide an intermediate level of security, requiring stronger and larger tools to open than an indicative seal, while not being as secure as a high security seal. They prevent accidental breakage or opening.
High security seals
These are the strongest level of seals, designed to provide a barrier that is stronger and more difficult to open. To open these seals requires the use of larger and stronger tools than the previous classifications. Standard testing levels require that high security seals are resistant to specific levels of pulling, bending and crushing to ensure their security.
More detailed information can be found at the ISO website here:
Usage
There is an increasing move towards using security seals to prevent terrorist acts. They are used as part of programs which show if a container has been opened after being initially sealed and loaded for transportation, ensuring that there has been no tampering.
On a much smaller scale, security seals are used in product manufacturing, to determine whether an item has been opened. They are often seen on high-cost and perishable items. Most consumers will have encountered some form of security seal in their purchasing history.
There is a great deal of choice when purchasing security seals, with companies such as https://acmeseals.co.uk/ stocking seals for all manner of requirements.
With uses in healthcare, agriculture, manufacturing, and law enforcement (just to name a few), the humble security seal is an invaluable tool in ensuring that items are safe.