Sectors and exposure situations
- Mining and tunnels. Diesel machinery in underground mines and tunnel construction, with limited ventilation and high concentrations.
- Transport and logistics. Loading docks, warehouses with diesel forklifts, bus stations, port and airport terminals, tolls and enclosed parking lots.
- Construction and civil works. Earthmoving machinery, generators and compressors in poorly ventilated spaces.
- Mechanical workshops and vehicle inspection. Engine testing, repairs, and technical inspection stations with vehicles running indoors.
- Emergency and maintenance services. Firefighters, road maintenance personnel and waste collection workers exposed to exhaust fumes.
- Agriculture and railways. Tractors and agricultural machinery, diesel locomotives and railway workshops.
Obligations arising from Royal Decree 665/1997
Since work involving exposure to diesel engine emissions is included in Annex I of Royal Decree 665/1997, employers must assess exposure by identifying the sources, tasks, and affected individuals, measuring elemental carbon in the respirable fraction according to INSST methods, and comparing it with the limit value of 0.05 mg/m3. Employers must prioritize replacing diesel engines with electric, gas, or other technologies whenever technically feasible. When this is not possible, they must reduce exposure to the lowest technically feasible level through closed systems, local exhaust gas extraction , general ventilation, particulate filters and engine maintenance, limiting the number of exposed personnel and exposure time, and implementing organizational measures for engine movement and shutdown.
The carcinogen regime also requires delimiting and marking risk areas, prohibiting eating, drinking and smoking in them, providing work clothes and suitable respiratory protection equipment when technical measures are insufficient, informing and training exposed persons, ensuring specific health surveillance, keeping a record of exposed persons with exposure levels and preserving the documentation for at least forty years after the end of exposure, and informing the labor authority when requested.
Effective technical and organizational measures
- Fleet replacement and renewal. Electric, gas, or state-of-the-art vehicles and machinery with certified particulate filters.
- Exhaust gas extraction. Extraction systems connected to the exhaust pipe in workshops and vehicle inspection, and forced ventilation with flow control in warehouses, parking lots and tunnels.
- Engine maintenance. Maintenance and inspection programs for combustion, filters, and exhaust gas treatment systems.
- Organization. Engine shutdown during loading and unloading, waiting areas outside the buildings, separation of vehicle and pedestrian traffic, and time limits in areas of higher concentration.
- Exposure control. Periodic measurements of elemental carbon, ventilation monitoring, and review of the assessment in response to changes.
- Respiratory protection. Suitable particle filtering equipment as a complementary and temporary measure, with training in its use.
Organizational application: how to manage exposure to diesel emissions
- Identify the sources (vehicles, machinery, generators), the areas and tasks with exposure and the people affected, including those from contracting companies.
- Evaluate the exposure with elemental carbon measurements of the respirable fraction according to INSST methods and compare it with the limit value, documenting the result.
- Analyze the possibilities for replacement (electrification, gas, fleet renewal) and plan their implementation with deadlines and budget.
- Implement the technical measures (exhaust extraction, ventilation, filters, maintenance) and organizational measures (engine shutdown, flow separation, times) and verify their effectiveness.
- Delineate and mark the areas, establish hygiene standards, provide additional respiratory protection where appropriate, and train and inform exposed individuals.
- Create and maintain the register of exposed persons, integrate specific health surveillance and keep the documentation for the legal period.
- Periodically review the assessment, measurements, and measures, especially in the event of fleet changes, facility changes, or process changes.
Preventive management software allows you to maintain the inventory of sources and areas of exposure, record measurements and their comparison with the limit value, manage the record of people exposed to carcinogens with the required preservation periods, schedule health surveillance and training, and monitor the implementation of substitution and control measures.
Limits and common mistakes
- Do not consider diesel emissions as a carcinogen and treat them only as a nuisance or a comfort problem.
- Relying on natural ventilation of ships and docks without measuring elemental carbon concentration.
- Keeping diesel vehicles and forklifts running indoors during waiting, loading and unloading.
- Use masks as the primary measure instead of extraction, ventilation, and replacement.
- Do not include contracting and transport companies in the evaluation or coordination.
- Omitting the registration of exposed persons and the specific health surveillance required by the carcinogen regime.
The specific evaluation depends on the sources, facilities and work organization; this sheet is for informational purposes only.
Practical example
Situation: A logistics center with indoor loading docks and diesel forklifts must adapt to the emissions limit value for diesel engines.
- Assessment. The prevention service identifies dock and corridor areas with truck and forklift traffic, performs elemental carbon measurements, and detects exceedances of the limit value on the docks during peak activity.
- Replacement and control. The company plans the gradual replacement of diesel forklifts with electric ones, installs forced ventilation on the docks, establishes the mandatory shutdown of truck engines during loading, and creates outdoor waiting areas.
- Organization. The areas are delimited and signposted, the staff and transporters are informed and trained, the register of exposed persons and specific health surveillance are implemented.
- Follow-up. Subsequent measurements confirm concentrations well below the limit value, the record is maintained in the management system and the assessment is reviewed after the fleet replacement is completed.
Regulatory and reference framework
- Royal Decree 665/1997, of May 12. Protection of workers against risks related to exposure to carcinogenic agents during work; Annex I and limit values.
- Royal Decree 427/2021, of June 15. Amends Royal Decree 665/1997 and includes work involving exposure to diesel engine emissions; transposes Directive (EU) 2019/130.
- Directive (EU) 2019/130 . Amends Directive 2004/37/EC and incorporates diesel engine emissions with their limit value.
- Directive 2004/37/EC . Protection of workers from the risks related to exposure to carcinogens or mutagens at work.
- INSST. Work involving exposure to diesel engine emissions . Composition, exposed sectors, effects and preventive measures.
- INSST. FTA-16/A25. Sampling and analysis of diesel engine emissions . Determination of elemental carbon in the respirable fraction.
- Royal Decree 374/2001, of April 6. Protection against risks related to chemical agents during work.
The limit value of 0.05 mg/m3 of elemental carbon applies generally from 21 February 2023 and in underground mining and tunnel construction from 21 February 2026.
