The figures
Of the 2,142 six-digit activity codes in the annex to the Communiqué on Workplace Hazard Classes, 356 sit in the highly hazardous class. That is 16.6 percent of the list, and it clusters in particular industry headings:
| Field | Highly hazardous codes | Total codes in field |
|---|---|---|
| Mining and quarrying (05-09) | 44 | 46 |
| Construction (41-43) | 60 | 72 |
| Coke, chemicals and pharmaceuticals (19-21) | 54 | 72 |
| Basic and fabricated metal manufacturing (24-25) | 46 | 101 |
| Waste collection, recovery and disposal (38) | 11 | 15 |
| Electricity, gas and steam supply (35) | 10 | 17 |
The densest NACE divisions
By count of highly hazardous codes the leaders are: manufacture of chemicals and chemical products (46 codes), manufacture of other non-metallic mineral products (37), basic metals (32), specialised construction activities (31), civil engineering works (24) and other mining and quarrying (23). Some divisions hold no exception at all: all 7 codes in coke and refined petroleum products, and all 13 codes in mining division 07, are highly hazardous.
Where there are none
All 35 codes across financial service, insurance and pension divisions 64-66 are low hazard. All 7 codes in computer programming, consultancy and information service divisions 62-63 are low hazard as well. In the education division, 33 of 37 codes are low hazard.
What the accident table says
In the 2025 social security statistics the total number of work accidents under the 4a scheme is 766,039 and the number of fatal work accidents is 1,931. Building construction (41) leads the fatality table with 360 deaths, followed by land and pipeline transport (49) with 288 and civil engineering works (42) with 145. Construction divisions sitting at the top of both the code distribution and the fatality table shows that the classification tracks what happens on site.
The class follows the code, not the industry
A workplace is highly hazardous not because it is called a construction company, but because the activity code its registration rests on is marked highly hazardous in the annex. Fatalities concentrating in divisions with a high share of highly hazardous codes is no coincidence; the classification follows the risk inherent in the work.
Check your own code in the hazard class lookup and see divisional distributions on the sector pages.