Storage Classification of Media Waste Particles
Store destroyed TOP SECRET media waste as OFFICIAL if under 3 mm, or as SECRET if 3-9 mm.
Plain language
When you destroy classified documents or data that was once labelled as TOP SECRET, the leftover bits must be stored carefully based on how small they are. If they're the size of crumbs, you treat them like regular documents, but if they're bigger, they need a bit more protection. This matters because it prevents the wrong information from getting out and keeps everything secure.
Framework
ASD Information Security Manual (ISM)
Control effect
Preventative
Classifications
TS
ISM last updated
Nov 2021
Control Stack last updated
18 May 2026
E8 maturity levels
N/A
Official control statement
The resulting media waste particles from the destruction of TOP SECRET media is stored and handled as OFFICIAL if less than or equal to 3 mm, or SECRET if greater than 3 mm and less than or equal to 9 mm.
Why it matters
Misclassifying TOP SECRET media waste particles (<=3 mm OFFICIAL, >3-9 mm SECRET) can lead to under-protection, exposure and compromise.
Operational notes
Measure and log shred/granulation particle size per batch; store <=3 mm waste as OFFICIAL and >3 mm to <=9 mm as SECRET, segregated and labelled.
Implementation tips
- Office Manager: Ensure staff understand that storage of media waste from TOP SECRET documents is dependent on the particle size after shredding. Train them to distinguish between particles under 3mm and those between 3mm and 9mm.
- Office Staff: When shredding sensitive documents, measure the resulting particle size. Use a simple plastic ruler to check if the particles are less than or equal to 3mm.
- IT Team: Set up a shredding protocol that specifies the settings for the shredders to produce particles of no more than 3mm. Ensure that all shredders are maintained and calibrated regularly.
- Record-Keeping Staff: Maintain a log of all shredded media including the date, type of media, and the size of particles. Ensure this log is regularly reviewed for accuracy.
- Security Officer: Regularly review and update the procedures for shredding and storing media waste, taking into account the latest guidelines and ensuring that all equipment is compliant with the stated requirements.
Audit / evidence tips
- AskThe shredding protocol document: Request the document detailing how media waste is to be handled GoodIncludes clear instructions on measuring particles and different handling procedures for various sizes
- AskMaintenance records of shredders: Request logs of maintenance and calibration GoodShows regular maintenance checks with specific attention to particle size capability
- AskTraining records: Request evidence of staff training on media waste procedures GoodIncludes up-to-date training logs and tests of staff understanding
- AskThe media waste storage log: Request a record that documents destruction events, the particle sizes, and storage actions taken GoodConsists of well-maintained logs with no gaps or inconsistencies
- AskSecurity procedure reviews: Request documentation of when and how often shredding and storage procedures are reviewed GoodIncludes recent review dates and notes on any changes made
Cross-framework mappings
How ISM-1729 relates to controls across ISO/IEC 27001, ISO/IEC 42001, Essential Eight, and ASD ISM.
ISO 27001
| Control | Notes | Details |
|---|---|---|
| layers Partially meets (2) expand_less | ||
| Annex A 5.12 | ISM-1729 mandates specific classification outcomes for TOP SECRET destruction residues based on measurable particle sizes | |
| Annex A 7.10 | ISM-1729 requires organisations to store and handle TOP SECRET media destruction waste at a downgraded classification based on particle s... | |
| sync_alt Partially overlaps (1) expand_less | ||
| Annex A 7.14 | ISM-1729 specifies how destroyed TOP SECRET media waste particles must be classified, stored, and handled after destruction based on part... | |
These mappings show relationships between controls across frameworks. They do not imply full equivalence or certification.