Friction Lid
Definition
The press-on metal lid used to seal evidence cans for fire debris. Seated by pressing firmly around the rim; allows field packaging with gloved hands without tools. Requires a tamper-evident sticker across the lid-rim interface to document integrity.
- Use
- Sealing evidence cans for fire debris
- Fit method
- Press-on, no tools required
- Compatible with
- Gloved-hand field packaging
- Integrity requirement
- Tamper-evident sticker across lid-rim interface
Common questions
Why is a friction lid preferred over a threaded or crimped seal for fire debris evidence?+
It seals with hand pressure alone at the scene, without a crimping tool or the risk of cross-threading, which matters when investigators are wearing gloves and working in a compromised, often hazardous environment. The seal is airtight enough to prevent evaporation of volatile ignitable liquid residues.
What happens if the tamper-evident sticker on a friction-lid can is broken or missing at the lab?+
It breaks the documented chain of custody for that exhibit, since the sticker is the record that the can was not opened between scene collection and lab receipt, and its absence or damage typically triggers a chain-of-custody challenge or additional verification before the sample is analysed.
Related terms
- ASTM E2998
- Standard Guide for Sampling Improvised Explosive Devices and Post-Blast Debris for Explosive Residue Analysis. Specifies cotton swabs, isopropanol or methanol pre-wetting, swabbing...
- Chain of Custody
- The documented chronological record of who collected, handled, transferred, and examined a piece of evidence. For digital evidence, chain of custody includes...
- Ion Mobility Spectrometry (IMS)
- A field-deployable analytical technique that separates ions by their mobility in an electric field at atmospheric pressure. Used for trace explosive detection...
- LC-MS/MS
- Liquid chromatography coupled to tandem mass spectrometry. The preferred confirmatory method for non-volatile organic explosives (PETN, RDX, TNT, NG) because it avoids...
- Mahazar
- The formal seizure list used in Indian criminal procedure (BNSS 2023) to document the collection of physical evidence at a scene. Prepared...
- Passive Headspace Concentration (PHC)
- ASTM E1412 extraction method. The sealed evidence container is heated at 60-80°C; volatilised hydrocarbons adsorb onto an activated charcoal strip suspended in...
- Selected Ion Monitoring (SIM)
- A GC-MS operating mode in which the mass spectrometer monitors only a set of pre-selected diagnostic m/z values, rather than scanning the...
- Tamper-Evident Sticker
- A self-adhesive label applied across the lid-rim or closure interface of an evidence container. Any disturbance of the container after sealing leaves...
- Unlined Metal Can
- The standard evidence container for fire debris analysis. 'Unlined' refers to the absence of internal plastic or epoxy coating, which would contribute...