Lockout/tagout and machine guarding are closely related machinery-safety topics, but they do not produce identical industry rankings in the HazIndex public results. This article compares two existing HazIndex rankings: the HazIndex lockout/tagout industry citation ranking and the HazIndex machine guarding industry citation ranking.
Both rankings cover OSHA citations issued from January 1, 2021 through December 31, 2025. Both use the same entity type, IndustryGroup, and the same metric, CitationCount. That makes the pair compatible for a narrow question: do the same industry groups appear near the top when HazIndex ranks recorded OSHA citations for lockout/tagout and machine guarding?
The published results indicate a strong overlap, but not a duplicate pattern. Eight industry groups appear in both top-ten lists, and four appear in both top-five lists. At the same time, the leading industry group changes: Plastics Product Manufacturing ranks first for lockout/tagout citations, while Architectural and Structural Metals Manufacturing ranks first for machine guarding citations.
Key findings
- The two top-ten lists share 8 of 10 industry groups in each ranking, or 8 of 12 industry groups in the combined top-ten set.
- Plastics Product Manufacturing ranks first in the lockout/tagout citation ranking with 872 recorded citations, but ranks third in the machine guarding ranking with 508 recorded citations.
- Architectural and Structural Metals Manufacturing ranks second for lockout/tagout citations with 739 recorded citations and first for machine guarding citations with 714 recorded citations.
- Four industry groups appear in both top-five lists: Plastics Product Manufacturing; Architectural and Structural Metals Manufacturing; Other Wood Product Manufacturing; and Machine Shops; Turned Product; and Screw, Nut, and Bolt Manufacturing.
- Among shared top-ten industry groups, the average absolute rank difference is 1.5 ranking positions, and the largest absolute rank difference is 2 positions.
- The top five published rows account for 24.9% of lockout/tagout citations and 28.9% of machine guarding citations in their respective rankings.
First ranking: lockout/tagout industry citations
The HazIndex lockout/tagout index covers OSHA control of hazardous energy violations associated with standard 1910.147 in the active HazIndex public release. The industry ranking publishes 100 IndustryGroup rows sorted by CitationCount.
Plastics Product Manufacturing leads the lockout/tagout list with 872 recorded citations. Architectural and Structural Metals Manufacturing follows with 739 citations, and Other Wood Product Manufacturing ranks third with 718 citations. The next two published rows are Machine Shops; Turned Product; and Screw, Nut, and Bolt Manufacturing with 628 citations and Highway, Street, and Bridge Construction with 597 citations.
Across the 100 published industry groups in this ranking, the published citation total is 14,281. The top three published rows account for 2,329 citations, or 16.3% of that total. The top five account for 3,554 citations, or 24.9%. The top ten account for 5,530 citations, or 38.7%.
That distribution is not limited to one narrow manufacturing label. The top ten include plastics, fabricated metals, wood products, machine shops, construction, water systems, motor vehicle parts, converted paper products, and animal slaughtering and processing. HazIndex is not using those rows to explain why citations occurred; the ranking shows where recorded citation totals are highest within the published IndustryGroup classification.
Second ranking: machine guarding industry citations
The HazIndex machine guarding index covers OSHA machine guarding violations associated with standard 1910.212 in the same active release. Its industry ranking also publishes 100 IndustryGroup rows sorted by CitationCount.
Architectural and Structural Metals Manufacturing leads the machine guarding list with 714 recorded citations. Machine Shops; Turned Product; and Screw, Nut, and Bolt Manufacturing ranks second with 518 citations, followed by Plastics Product Manufacturing with 508 citations. Other Fabricated Metal Product Manufacturing ranks fourth with 450 citations, and Other Wood Product Manufacturing ranks fifth with 317 citations.
The published citation total across the 100 machine guarding industry-group rows is 8,663. The top three published rows account for 1,740 citations, or 20.1% of that total. The top five account for 2,507 citations, or 28.9%. The top ten account for 3,481 citations, or 40.2%.
The machine guarding ranking is therefore somewhat more concentrated near the top than the lockout/tagout ranking, using the published totals. The difference is modest: 3.8 percentage points for the top three, 4.0 percentage points for the top five, and 1.5 percentage points for the top ten.
Where the rankings overlap
The strongest overlap appears in the upper tier. Plastics Product Manufacturing and Architectural and Structural Metals Manufacturing both appear in the top three of each ranking. Other Wood Product Manufacturing and Machine Shops; Turned Product; and Screw, Nut, and Bolt Manufacturing also appear in both top-five lists.
The shared top-ten industry groups are not merely present in both lists; most sit in similar relative positions. Among the eight shared top-ten groups, the average absolute rank difference is 1.5 positions. The largest absolute difference is 2 positions. Animal Slaughtering and Processing is ranked tenth in both lists.
| Industry group | Lockout/tagout rank | Machine guarding rank |
|---|---|---|
| Architectural and Structural Metals Manufacturing | 2 | 1 |
| Plastics Product Manufacturing | 1 | 3 |
| Machine Shops; Turned Product; and Screw, Nut, and Bolt Manufacturing | 4 | 2 |
| Other Wood Product Manufacturing | 3 | 5 |
| Other Fabricated Metal Product Manufacturing | 6 | 4 |
| Animal Slaughtering and Processing | 10 | 10 |
This overlap shows that the two HazIndex rankings identify several of the same industry groups near the top during the same period. It does not show that the two categories have the same underlying citation profile, and it does not explain why any industry group appears in either ranking.
Where the rankings diverge
The most visible divergence is the first-ranked row. Plastics Product Manufacturing is first for lockout/tagout and third for machine guarding. Architectural and Structural Metals Manufacturing is second for lockout/tagout and first for machine guarding. Machine Shops; Turned Product; and Screw, Nut, and Bolt Manufacturing moves from fourth in lockout/tagout to second in machine guarding.
The unique top-ten entries are also useful. Water, Sewage and Other Systems and Motor Vehicle Parts Manufacturing appear in the lockout/tagout top ten but not the machine guarding top ten. Bakeries and Tortilla Manufacturing and Household and Institutional Furniture and Kitchen Cabinet Manufacturing appear in the machine guarding top ten but not the lockout/tagout top ten.
Some industry groups sit just outside the other list's top ten. Bakeries and Tortilla Manufacturing ranks eleventh in the lockout/tagout ranking but eighth in the machine guarding ranking. Motor Vehicle Parts Manufacturing ranks eighth in lockout/tagout but fifteenth in machine guarding. Those shifts are factual rank differences within published HazIndex outputs, not causal explanations.
Concentration comparison
Both rankings are moderately concentrated in their top ten published rows. The lockout/tagout top ten accounts for 38.7% of the published lockout/tagout citation total. The machine guarding top ten accounts for 40.2% of the published machine guarding citation total.
The top-five comparison is slightly wider. Lockout/tagout's top five account for 24.9% of the published total, while machine guarding's top five account for 28.9%. The difference indicates that the machine guarding ranking places a somewhat larger share of published citations in the first five industry groups. The rankings alone do not establish why that difference appears.
What the comparison does and does not show
This comparison summarizes recorded OSHA enforcement outcomes as published by HazIndex. HazIndex is an independent publisher of workplace-safety rankings and analysis derived from public OSHA enforcement data. OSHA is the authoritative source of the underlying public enforcement records; HazIndex publishes the aggregations, rankings, calculations, comparisons, visualizations, and written analysis.
The comparison does not normalize for industry size, number of establishments, employment, hours worked, production volume, or inspection volume. It also does not state that citation counts measure injury frequency, current safety conditions, or the complete safety performance of an industry group. The rankings compare recorded citations in published HazIndex outputs for a defined period.
Penalty totals are visible in the source ranking rows, but they are not the metric used for this article's selected pair. This article compares CitationCount rankings only because the compatible non-employer pair available in the public read model uses the same metric and entity type across two related safety indexes.
Methodology and sources
The selected rankings use the same active HazIndex public release: citations issued from January 1, 2021 through December 31, 2025. Both rankings use EntityType = IndustryGroup and SortMetric = CitationCount. The ranking pages state that the rankings are generated from the active HazIndex public release using materialized OSHA-derived ranking rows, yearly period values, and release metadata.
Readers can review the source rankings directly on HazIndex: the lockout/tagout industry citation ranking and the machine guarding industry citation ranking. The broader HazIndex workplace-safety indexes hub lists the active public safety indexes, and the HazIndex dataset license and usage page describes terms for citing and reusing HazIndex datasets and derived products.
For underlying public enforcement records, readers should consult official OSHA resources, including the OSHA data page, the OSHA Establishment Search, and OSHA enforcement information. Official OSHA records should be used for authoritative case-level details.
Related HazIndex Insights
These related HazIndex Insights provide additional context from the same public release and nearby ranking topics.
- Lockout/Tagout OSHA Citations by Industry: What the Ranking Shows
- Machine Guarding OSHA Citations by Industry: What the Ranking Shows
- What the Lockout/Tagout OSHA Violations Index Shows
- What the Machine Guarding OSHA Violations Index Shows
Conclusion
The lockout/tagout and machine guarding industry citation rankings substantially overlap, with eight shared industry groups in their top tens and four shared industry groups in their top fives. That overlap is the clearest agreement between the two rankings.
The clearest divergence is the change in leadership and the unique top-ten entries. Plastics Product Manufacturing leads lockout/tagout citations, while Architectural and Structural Metals Manufacturing leads machine guarding citations. Water, Sewage and Other Systems and Motor Vehicle Parts Manufacturing appear only in the lockout/tagout top ten, while Bakeries and Tortilla Manufacturing and Household and Institutional Furniture and Kitchen Cabinet Manufacturing appear only in the machine guarding top ten.
Together, the rankings show why related OSHA citation categories should be compared carefully. Similar entity type and metric make the comparison valid, but the published results are not interchangeable. Readers can use the two original HazIndex ranking pages to inspect the complete industry lists and the broader context for each safety index.