Case Study: Hazardous Substances Assessment at a Copper Manufacturing Facility

A recent hazardous substances assessment was conducted at a copper manufacturing facility specialising in the production of high conductivity copper castings. The site features open-plan production floors with approximately 30-40 operatives.
 
In the copper smelting and casting industry, several inhalation hazards are encountered during different stages of the process. Inhalable and respirable dust are prevalent throughout the facility, particularly during the handling and processing of raw materials and products. Workers in the moulding, fettling, de-core, and casting areas are especially at risk of exposure to these types of dust.
 
Respirable crystalline silica is another significant hazard, encountered mainly during activities involving sand, such as moulding and knocking out. This substance, present in most rocks and sand, becomes airborne and poses a serious inhalation risk.
 
Copper fume, generated during the smelting and casting processes, is a critical hazard. This is particularly a concern for employees working in close proximity to melting and pouring operations. Additionally, welding fume, a complex mixture of airborne particles produced during welding operations, contains various metal oxides and is encountered by welders and those nearby.
 
Formaldehyde, used in certain binding agents during the moulding process, presents an inhalation risk for workers in this area. Similarly, phenol, used in resins and binders, poses a risk in the same stage of the process.
 
Potassium hydroxide, utilised in various cleaning and processing operations, is another inhalation hazard found throughout different parts of the facility. Workers in cleaning and maintenance roles are most likely to encounter this substance.
 
Nickel and chromium compounds, present in some alloys and protective coatings, are encountered during the handling and processing of these materials, particularly in the welding and casting stages. Manganese, found in welding rods and some alloys, poses a risk primarily during welding operations.
 
Lastly, iron oxide, a by-product of smelting and also found in welding fumes, is encountered by workers involved in both the smelting and welding processes.
 
By identifying the specific hazards and the stages of the process where they are encountered, appropriate control measures can be implemented to mitigate the risks and protect the health and safety of the workers.

Health Effects of Respirable Crystalline Silica in Smelting and Casting

 
Respirable crystalline silica, a significant hazard in the smelting and casting industry, poses severe health risks to workers. Inhalation of fine silica particles can lead to silicosis, a chronic and often fatal lung disease. Silicosis is characterised by inflammation and scarring of the lung tissue, leading to symptoms such as shortness of breath, cough, and fatigue. Prolonged exposure to respirable crystalline silica also increases the risk of developing other serious conditions, including chronic obstructive pulmonary disease (COPD) and lung cancer.
 
According to the Health and Safety Executive (HSE), workers in the smelting and casting industry are particularly at risk due to the high levels of silica dust generated during activities such as moulding and knocking out. Statistics from the HSE indicate that over 500,000 workers in the UK are exposed to silica dust annually, with a significant proportion working in foundries and related industries. The International Agency for Research on Cancer (IARC) classifies crystalline silica as a Group 1 carcinogen, indicating sufficient evidence of its carcinogenicity in humans.
 
The severity of silicosis and other related diseases underscores the importance of effective control measures and monitoring to protect workers from the dangers of respirable crystalline silica.

Results of Silica Exposure Monitoring

 
The monitoring results revealed several critical areas where exposure limits were exceeded, highlighting significant occupational health risks. Inhalable dust levels were found to surpass the permissible exposure limits in multiple operations, including moulding, fettling, de-core, and casting. Specifically, the moulding shop had inhalable dust concentrations ranging from 2.40 to 23 mg/m³, equating to 24-230% of the Occupational Exposure Limit (OEL). In the fettling area, levels reached as high as 23 mg/m³, which is 230% of the OEL.
 
Respirable crystalline silica, a known carcinogen, also exceeded safe limits, particularly during moulding and knockout processes. For instance, in the mould shop, respirable crystalline silica concentrations varied between <0.10 to 0.16 mg/m³, reaching up to 160% of the OEL. The knockout processes showed similar concerning results, with respirable crystalline silica levels at times hitting 110% of the OEL.
 
Additionally, copper exposure presented a significant risk, especially in casting operations. The measured copper concentrations in casting ranged from 0.27 to 1.50 mg/m³, with the highest levels reaching 750% of the OEL, indicating an urgent need for improved control measures to protect workers' health.
 
These findings underscore the necessity for immediate intervention, including enhanced ventilation systems, rigorous use of personal protective equipment, and ongoing monitoring to ensure compliance with health and safety standards.
 

Occupational Exposure Survey Recommendations

 
Immediate and routine actions were recommended to control exposure and protect employees' health. It is essential to ensure proper storage and regular replacement of respiratory protective equipment (RPE). Workers must use RPE consistently during tasks that involve high exposure to hazardous substances. Additionally, local exhaust ventilation (LEV) systems should be operated and maintained effectively, particularly in casting and welding areas. Installing air flow indicators and maintaining a logbook for LEV systems will help monitor their functionality.
 
A formal health surveillance programme should be implemented to monitor workers' health over time. Regular training sessions are also crucial, focusing on the use of control measures and the importance of RPE. Employees should be informed about the potential health risks associated with their work environment and the findings of the monitoring report. These measures will help ensure a safer workplace and better protect workers from inhalation hazards.
 

Conclusion On Improvement of Crystalline Silica Exposure Management

 

The assessment at the copper manufacturing facility revealed significant exposure to hazardous substances, necessitating immediate action to improve control measures. The recommendations provided by Sysco Environmental Ltd aim to reduce exposure levels and enhance the overall health and safety of the employees. Regular monitoring and maintenance of control systems, coupled with comprehensive training and health surveillance, are crucial for ensuring a safe working environment.