Case Study: Diesel Exhaust Fumes Safety Audit in a Sprinkler Plant Room.

In February 2024, Sysco Environmental Ltd conducted a comprehensive diesel exhaust fumes air quality assessment in a sprinkler plant room located in the basement of a residential building in London. The primary objective was to evaluate the levels of diesel fumes emitted during the operation of an emergency diesel generator and assess the potential health risks to employees.
Emergency generators are critical components in many buildings, especially in environments where continuous power supply is crucial. They are designed to provide backup power during electrical outages, ensuring that essential systems and services remain operational. These generators are typically powered by diesel engines due to their reliability and ability to generate substantial amounts of power quickly.

To ensure readiness and reliability, emergency generators must be tested regularly. Standard practice involves weekly testing for short durations, usually around 30 minutes, to confirm that the generator will function correctly in the event of a power failure. During these tests, the generator is run under load to simulate actual operating conditions, which is essential for maintaining the system's reliability and preventing potential failures during an emergency.

In this specific case, the emergency diesel generator is located in a basement plant room that also houses three large water tanks, motors, and pumps. The room’s confined nature and limited ventilation can lead to the accumulation of diesel fumes during generator testing. Although the generator’s exhaust is vented outside, any leaks or inefficiencies in the exhaust system can result in the ingress of harmful emissions into the workspace.
 
Potential diesel fumes exposure problems are exacerbated by the infrequent use of emergency generators. Unlike equipment that operates continuously and is subject to stringent diesel emission controls and regular maintenance, emergency generators may not receive the same level of attention. This can result in overlooked issues such as minor leaks, inadequate exhaust systems, and insufficient ventilation, all of which can contribute to elevated levels of hazardous emissions during operation.
 
In enclosed or semi-enclosed environments, where testing occurs while an operative is present, it is crucial to evaluate the air quality and implement necessary controls to mitigate any health risks from exhaust emissions. The confined space and presence of other equipment further complicate the situation, necessitating thorough and regular air quality assessments to ensure a safe working environment.

Methodology

 
Sysco Environmental Ltd employed a multi-faceted approach to evaluate personal exposure to diesel exhaust fumes and other hazardous substances during the operation of the emergency diesel generator. The methodology involved the use of personal samplers, portable meters, and dataloggers to provide a comprehensive assessment of air quality in the sprinkler plant room.
 
Personal Samplers:

Airborne particulates, which form a significant part of diesel exhausts were collected using Personal Samplers. These samplers are worn by operatives to measure their exposure to contaminants in real-time, providing an accurate representation of the personal exposure levels during the testing of the diesel generator. This method is crucial for DEEE monitoring, ensuring that personal exposure to diesel exhaust fumes is accurately assessed.
 
Portable Meters and Dataloggers:

To complement the personal sampling, portable meters and dataloggers were employed to measure the levels of gases such as carbon dioxide (COâ‚‚), carbon monoxide (CO), particulates, and formaldehyde. These instruments provided continuous monitoring and real-time data, offering insights into the temporal variations and peak concentrations of these contaminants during the generator testing.
 
- Carbon Dioxide and Carbon Monoxide: Direct reading instruments were used to measure COâ‚‚ and CO levels. These portable meters are equipped with sensors that detect exhaust gas concentrations, providing immediate feedback on the air quality within the plant room.
 
- Particulate Matter: Portable particulate monitors were used to assess the levels of exhaust fumes related airborne particulates, a significant component of diesel exhaust. These monitors measured the concentration of particulates of various sizes, including PM10 and PM2.5, which are known to have adverse health effects.
 
- Formaldehyde: Dataloggers equipped with formaldehyde sensors were used to detect the presence of this toxic gas. Formaldehyde is a known irritant and potential carcinogen, making its monitoring crucial during diesel generator testing.
 
Compliance was evaluated based on the Health and Safety Executive (HSE) document ‘L5, The Control of Substances Hazardous to Health Regulations 2002 (as amended)’ and ‘The Approved Code of Practice and Guidance’. Personal exposure levels were compared with the values stated in the UK HSE document ‘EH40/2005 Workplace Exposure Limits - Containing the List of Workplace Exposure Limits for Use with The Control of Substances Hazardous to Health Regulations (As Amended)’.
 
This robust methodology ensured a thorough evaluation of the air quality in the plant room, highlighting any potential health risks associated with diesel exhaust emissions and providing a basis for recommendations to maintain a safe working environment. The exact test suite was tailored to the specific situation and operational parameters of the setup, ensuring a comprehensive and relevant assessment.

 Understanding Diesel Engine Exhaust Emissions (DEEEs)

 
Diesel engine exhaust emissions (DEEEs) consist of a complex array of substances generated during the combustion of diesel fuel. These emissions include:
 
Gases: Diesel exhaust commonly contains gases such as carbon dioxide (COâ‚‚), carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NOâ‚‚). Carbon monoxide is particularly dangerous, as it is a poisonous gas that can hinder the body’s ability to transport oxygen effectively.
 
Vapours: The exhaust also contains vapours, including hydrocarbons. Inhalation of these vapours, which include volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs), can be harmful over extended periods.
 
Liquid Aerosols: These minute liquid droplets can carry toxic chemicals deep into the lungs, posing significant respiratory health risks.
 
Particulate Matter: Diesel exhaust is rich in particulate matter, notably soot (carbon particles). This soot can be ten times more prevalent than in petrol exhaust and often contains toxic substances like polycyclic aromatic hydrocarbons (PAHs), known carcinogens.
 
Given this complex composition, diesel exhaust is highly visible and poses substantial health hazards. The International Agency for Research on Cancer (IARC), under the World Health Organisation (WHO), classifies DEEEs as Group 1 carcinogens, indicating a definite link to cancer in humans. There is robust evidence connecting DEEEs to an increased risk of lung cancer and some evidence pointing to a connection with bladder cancer.
 
The Office of Rail and Road (ORR) stresses the necessity of controlling DEEE exposure in railway environments, urging strict adherence to the Control of Substances Hazardous to Health (COSHH) regulations. This framework prioritises measures to eliminate or minimise exposure to hazardous substances, thereby safeguarding workers.
 
Additionally, the Health and Safety Executive (HSE) offers detailed guidelines on managing DEEE exposure in workplaces through its publication HSG187: Control of Diesel Engine Exhaust Emissions in the Workplace. This guide provides comprehensive strategies for employers to protect their employees from the hazards of diesel exhaust effectively.
 

 Health Risks of Diesel Exhaust Emissions

 
Exposure to diesel exhaust emissions can result in serious health issues, including:
 
Irritation: A primary effect of DEEEs exposure is irritation of the eyes and respiratory tract, particularly in environments with high levels of white smoke.
 
Respiratory Issues: DEEEs, especially when involving blue or black smoke, can cause coughing and breathlessness.
 
Cancer: The IARC has classified DEEEs as Group 1 carcinogens, linking exposure to increased risks of lung and bladder cancer.
 
By understanding the components and risks associated with diesel engine exhaust emissions, measures can be implemented to mitigate exposure and protect public health.
 

 Conclusions

 
The air quality assessment conducted by Sysco Environmental Ltd provided comprehensive insights into the levels of diesel exhaust emissions and other hazardous substances in the Sprinkler Plant Room. The results and subsequent analysis revealed that the concentration levels of all assessed substances, including elemental carbon, nitrogen oxides, carbon dioxide, and carbon monoxide, did not exceed the Workplace Exposure Limits (WELs). This conclusion offers several significant benefits to the client:
 
1. Verification of a Safe Environment:
   The assessment verified that the environment within the Sprinkler Plant Room is safe for use during emergency operations. This reassurance is crucial, particularly during the testing and operation of the emergency diesel generator, ensuring that employees can perform their duties without undue risk to their health.
 
2. Protection for Employees and Public:
   The results confirmed that employees working within the plant room, as well as the public in the vicinity, are not exposed to excessive amounts of diesel exhaust fumes. This finding mitigates concerns about acute and chronic health risks associated with exposure to harmful emissions.
 
3. Basis for Comprehensive Health and Safety Audit:
   The detailed report provides a solid foundation for a comprehensive health and safety audit. It offers evidence-based data that can be used to further evaluate and enhance workplace safety measures, ensuring compliance with regulatory standards and best practices.
 
4. Verification of Safe Equipment Operation:
   The assessment also serves as verification to building insurers that all installed equipment, including the emergency diesel generator, is operating safely. This verification can help in maintaining insurance coverage and potentially reducing premiums due to demonstrated safety and compliance.
 
5. Compliance with Regulatory Standards:
   By confirming that emission levels are within permissible limits, the report helps ensure that the client complies with relevant health and safety regulations, including those set by the Health and Safety Executive (HSE) and the Control of Substances Hazardous to Health (COSHH) regulations.
 
6. Enhanced Confidence in Safety Protocols:
   The assessment enhances confidence in the safety protocols and measures implemented by the client. It demonstrates a proactive approach to managing environmental and occupational health risks, which can improve employee morale and public perception.
 
In summary, the air quality assessment by Sysco Environmental Ltd not only confirmed the safety of the working environment but also provided substantial benefits by ensuring regulatory compliance, protecting health, and verifying the safe operation of essential equipment. These outcomes collectively contribute to a safer, healthier workplace and enhance the overall safety and operational integrity of the building.