Mixer and crusher safety inspections: coverage and first-inspection deadlines
Preparing for mixer and crusher safety inspections
An equipment name alone does not settle both inspection coverage and the first-inspection deadline. Mixers can differ in drive arrangement, motor capacity, internal volume and feed or discharge access. Establish coverage first, compare the installation-completion date with the deadline rules, and then examine guards, interlocks and electrical controls.
Separate equipment categories, exclusions and inspection criteria
Article 78(1), items 14 and 15, of the Occupational Safety and Health Act Enforcement Decree lists mixers and crushers or grinders as inspection categories. Notice 2026-50, Procedures for Safety Inspections, Annex 1 defines detailed coverage and exclusions. Notice 2026-49, Safety Inspection Notice, Articles 28 and 30 and Annexes 13 and 14 set inspection criteria. Both notices took effect on 26 June 2026.
First-inspection timing is governed by Article 126 of the Enforcement Rule and Article 4 of the Addenda to Ministry Ordinance 419. Meeting a guarding criterion does not itself mean that equipment is excluded from inspection.
Compare mixing action, capacity and access
Annex 1, item 14 covers mixers that stir or mix material using blades fixed to a powered rotating shaft. Compare the actual construction and use against each exclusion below; any one may apply.
| Item | Exclusion |
|---|---|
| a | Rotating-container mixers that mix by rotating the entire outer vessel |
| b | Pneumatic-agitation mixers using a jet device |
| c | Drive-motor capacity of 1.2 kW or less |
| d | Industrial mixer internal volume below 200 litres |
| e | Food mixers used with a vertical drive shaft |
| f | Enclosed automatic feed and automatic discharge after processing, with a structure preventing human access |
| g | Partitions enclosing the top, bottom and sides except feed and discharge openings; presence-sensing safeguards at both openings; stopping when an inspection door opens |
| h | Water-treatment equipment for water supply or sewage, or sludge-dilution tanks, used to treat pollutants or purify water |
| i | Domestic equipment used by the general public |
| j | Pressure vessels inspected under the Occupational Safety and Health Act or whose pressure-vessel safety has been confirmed under another statute, such as the High-Pressure Gas Safety Control Act |
The 1.2 kW limit means “or less,” including the boundary value. The 200-litre limit means “below”: an exactly 200-litre mixer is not excluded by that volume item alone. Failure to meet one numerical exclusion does not remove the need to check the other items.
The partition provision requires more than a surrounding fence. It also includes presence-sensing safeguards at the feed and discharge openings and stopping when an inspection door opens. Automatic feeding during normal operation does not by itself establish that access is impossible. Compare doors and openings with the drawings and actual installation.
Both crusher capacity thresholds use “below”
Annex 1, item 15 covers crushers or grinders that break material through powered cutting tools on a rotating device or impact from a reciprocating mechanism. Apply their own exclusions rather than the mixer thresholds.
| Item | Exclusion |
|---|---|
| a | Crushing or grinding capacity below 50 kg per hour |
| b | Drive-motor capacity below 7.5 kW |
| c | Equipment using steel or ceramic balls (ball mills) or gas (jet mills), operated without a rotating device or reciprocating mechanism |
| d | Food-processing equipment for vegetables, meat, fish or other food |
| e | Equipment capable of powered travel to unspecified locations, such as mobile wood crushers or grinders and vehicle-mounted shredders |
| f | Enclosed automatic feed and automatic discharge after processing, with a structure preventing human access |
| g | Partitions enclosing the top, bottom and sides except feed and discharge openings; presence-sensing safeguards at both openings; stopping when the access door opens |
| h | Domestic equipment used by the general public or office document shredders |
| i | Equipment whose safety has been confirmed under another statute |
Both 50 kg per hour and 7.5 kW use “below.” An exact value of 50 kg or 7.5 kW does not qualify under that numerical exclusion alone. Other exclusions remain separate. For a ball or jet mill, check the accompanying rotating-device and reciprocating-mechanism condition rather than relying only on the equipment name.
- 1. Mixer scope: Powered shaft with fixed blades for stirring or mixing · Compare separate exclusions, including rotating vessels and air agitation.
- 2. Mixer size exclusions: Motor: 1.2 kW or less · Industrial vessel capacity: below 200 L · Also compare the other type and guarding exclusions.
- 3. Crusher / grinder: Powered rotating cutting tools or reciprocating impact · Check the equipment category and detailed exclusions separately.
- 4. Crusher size exclusions: Capacity: below 50 kg per hour · Motor: below 7.5 kW · Also compare the other type and guarding exclusions.
- 5. Duties still apply: General guarding and maintenance-stop duties remain. · Size thresholds are only part of the exclusion criteria.
Use the installation-completion date for the first inspection
Article 4 of the Addenda to Ministry Ordinance 419 divides first inspections for mixers, crushers and grinders already installed at workplaces as of 26 June 2026 into three groups. Establish the installation-completion date from records rather than equating it with manufacture or purchase.
| Installation completed | First safety inspection | Addenda Article 4 |
|---|---|---|
| Before 2013-03-01 | 2026-06-26 to 2026-12-25 | Item 1 |
| 2013-03-01 to 2023-06-26 | 2026-06-26 to 2027-06-25 | Item 2 |
| 2023-06-27 to 2026-06-25 | Within 6 months measured from the date marking 3 years after installation completion | Item 3 |
For all three groups, subsequent inspections are due every 2 years from the first safety inspection. Separately, the ordinary cycle in Enforcement Rule Article 126(1)(3) requires the first inspection within 3 years after installation completion and every 2 years thereafter.
- 1. Before 2013-03-01: First: 2026-06-26 to 2026-12-25 · Then every 2 years from the first inspection.
- 2. 2013-03-01 to 2023-06-26: First: 2026-06-26 to 2027-06-25 · Then every 2 years from the first inspection.
- 3. 2023-06-27 to 2026-06-25: Within 6 months of the date 3 years after installation · Then every 2 years from the first inspection.
- 4. General schedule: First inspection within 3 years after installation · Every 2 years thereafter.
- 5. Installed on 2026-06-26: Do not assign it to a transitional band by assumption. · Confirm the installation record and rule with the inspection body.
Do not place equipment completed on 26 June 2026 into item 3: that item ends on 25 June, while the introductory provision says “as of 26 June.” For an installation completed on the boundary date, confirm the completion facts and applicable provision with the competent authority. For the third group, calculate the 6-month period from the 3-year anniversary of installation completion.
Closing the mixer cover must not itself restart it
Notice 2026-49 Article 28 and Annex 13 set mixer inspection criteria. Covers or barriers are required where an opening creates a fall hazard, with protection also required against contact with driven parts or flying material. These are inspection criteria, separate from the coverage decision in Annex 1.
Annex 13 item 5 requires functioning interlocks that stop the blades during material removal, cleaning, servicing or repair. Opening the cover must stop rotation; after it closes, operation must require use of the start switch. Closing a cover must not itself restart the mixer.
A cover interlock may be omitted where the inspection opening’s diameter, including height and width, is below 120 mm and the distance to the rotating device is at least 850 mm. Both conditions apply together. A small opening alone is insufficient. Compare locking devices, power isolation, emergency stops and the remaining requirements separately against Annex 13.
Prevent access until rotor movement has stopped
Notice 2026-49 Article 30 and Annex 14 govern crushers and grinders. The chamber must withstand operating impacts and impacts from discharged material or foreign objects. Opening protection extends beyond the inlet to discharge and maintenance or cleaning openings.
Annex 14 item 5 requires an interlocked guard that must be closed and locked for operation and cannot open during operation. A movable hopper or feeder requires adequate distance or an interlocked cover preventing bodily access to the chamber until the rotor stops. Discharge, servicing and cleaning openings must likewise prevent contact until all rotor movement stops.
Where a locking interlocked guard is markedly impracticable because of machine construction or work characteristics, item 5(d) sets the exception. It requires one or more specified measures: interlocked access-door stopping with restart only from outside, a presence-sensing safeguard before the inlet, or inaccessible feeding with sufficient safety distance, subject to the original conditions. Operating convenience alone is not an exemption.
The rotor restraint in item 6 prevents manual rotation after stopping. The provision includes exceptions for products made and installed before the self-declaration regime and for the specified rotor-inertia condition. Compare manufacture and installation timing and the rotor construction to determine whether the exception applies. A stop signal, actual cessation of rotation and restraint during maintenance are separate functions.
Inspection exclusions do not remove general safety duties
Exclusion from the safety-inspection scope does not eliminate rotating-part contact or unexpected-startup hazards during cleaning and maintenance. Article 87(8) and (9) of the Occupational Safety and Health Standards Rule address stopping or interlocking measures for opening covers or contact hazards on crushers, grinders and mixers. When a cover or enclosure must be opened during operation, at least one measure is required: stopping before opening, an interlock that automatically stops the machine when opened, or a presence-sensing protective device that stops it when a body enters the danger zone. Article 92 requires stopping and safeguards against restart by another person where servicing work could endanger workers. An inspection exclusion does not justify removing guards or clearing a blockage while running.
Link the exclusion relied upon to nameplate or specification evidence, access-prevention arrangements and installation-completion records. This makes both the scope decision and later inspection preparation traceable. If modifications change the drive arrangement or feeding method, compare the previous decision with the equipment now installed.
Questions when preparing for inspection
Does the purchase date start the first-inspection period?
Use installation completion. Distinguish it from purchase and manufacture, then compare the applicable group in Ordinance 419 Addenda Article 4.
Does having a cover remove equipment from inspection coverage?
A cover alone does not decide coverage. Compare all relevant access-prevention, automatic feeding and discharge, and interlocked-stopping conditions in the applicable Annex 1 exclusion.
Related reading
Primary sources
- Occupational Safety and Health Act Enforcement Decree, Article 78
- Procedures for Safety Inspections, Notice 2026-50
- Safety Inspection Notice 2026-49
- Enforcement Rule Article 126 and Ordinance 419 Addenda Article 4
- Occupational Safety and Health Standards Rule, Articles 87 and 92
- Notice 2026-50, Annex 1
- Notice 2026-49, Annex 13
- Notice 2026-49, Annex 14