A
Existing or Imminent Danger
Out of service immediately
A Category A defect is the most serious classification. It means the competent person has found a defect that represents an existing danger or an imminent risk of serious personal injury.
Required actions
→Equipment must be taken out of service immediately
→Competent person must send a copy of the report to the relevant enforcing authority (HSE or local authority)
→Dutyholder must not return equipment to use until defect is rectified and verified
→Remediation must be documented and a further examination carried out before returning to service
Example defects
·Cracked hook — load could detach without warning
·Brake failure on a hoist — load could drop
·Corroded chain link beyond safe limits
·Structural crack in crane boom
·Overload limiter inoperative on equipment regularly loaded near SWL
B
Future Danger — Repair Within Timescale
Action within stated deadline
A Category B defect is a finding that is not currently dangerous but will become dangerous if not remedied within a specified timescale. The competent person must state the deadline in the report.
Required actions
→Equipment may continue in use until the stated deadline
→Repair must be completed before the deadline — not after
→A further examination should confirm the repair before the equipment is used beyond the deadline
→The deadline is a legal requirement, not a guideline — exceeding it with no action is a compliance failure
Example defects
·Worn rope strands approaching discard criteria
·Corrosion progressing but not yet at dangerous level
·Hydraulic seals showing early signs of failure
·Missing safety pin — not currently creating a hazard but could in foreseeable circumstances
·Wear on drum grooves approaching maximum tolerance
C
Observation — Monitor
Record and monitor
A Category C entry is an observation or minor finding that does not pose an immediate or future risk but is worth noting. No mandatory action timescale is set, but it must be recorded in the report.
Required actions
→No immediate action required
→Record the finding and monitor at subsequent examinations
→If the same finding recurs across multiple examinations, consider escalating to Category B
→Use C-category history to inform maintenance planning
Example defects
·Minor surface corrosion with no structural significance
·Label partially obscured — still readable
·Minor scoring on sheave groove — within acceptable limits
·Slight play in pin — within manufacturer tolerance
·Paint damage exposing bare metal — cosmetic only
The Critical Point: Category A Triggers HSE Notification
Most inspection companies know about Cat A notification in theory. In practice, it is sometimes skipped — particularly when the examiner and the client have a long commercial relationship and the defect seems borderline. This is dangerous. If the equipment subsequently fails and causes injury, and the HSE discovers a Cat A finding was not notified, both the examiner and the dutyholder face prosecution. The notification obligation is statutory. It cannot be waived by agreement.
Cat A, B and C — tracked automatically in Lolerflow
Every defect is categorised, tracked, and flagged. Cat A defects trigger an immediate alert. Cat B deadlines are tracked against the calendar. Nothing gets missed. 30-day free trial.
Start free trial →What are the three LOLER defect categories?+
Category A: existing or imminent danger — equipment must be taken out of service immediately and HSE notified. Category B: defect that will become dangerous if not repaired within a specified period — equipment can remain in use until the deadline. Category C: observation or minor finding — no immediate action required but should be monitored.
What must happen when a Category A defect is found?+
The competent person must immediately notify the dutyholder and send a copy of the report to the relevant enforcing authority (HSE or local authority). The dutyholder must take the equipment out of service and must not return it to use until the defect is rectified. Continuing to use equipment after a Category A finding is a serious criminal offence.
Does a Category C defect need to be repaired?+
Not immediately — Category C is an observation or minor finding that does not pose an immediate or near-future risk. However, it must be recorded in the examination report, and the dutyholder should monitor it. If the same defect appears across multiple consecutive examinations, it may indicate progressive deterioration that should be escalated.