**1. Introduction**

The renewable energy sources, that have been well developed in Italy, include biogas, which is mainly obtained from the anaerobic digestion (AD) of agricultural and livestock biomasses. Italy is the second biogas producer in Europe, after Germany, and by the end of 2015, about 1555 biogas plants were operating, of which 77% were powered by agricultural matrices [1]. Biomethane production from biowaste is also an important contributor to reach the objectives established by the European Directive 2009/28/EC on renewable energies [2]. The Italian

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decree on incentives for producing biomethane opens new development perspectives for renewable energies from biowaste, as this biofuel could be used in vehicles as a substitute for fossil fuel and replace the natural gas dependence in domestic, commercial as well as industrial consumptions [3]. Most of the biogas production plants are of small or medium size, therefore, falling below the thresholds for the application of legislation aimed at the control of major accidents, as the Seveso Directive [4]. In Italy, in 2010, there were approximately 100,000 workers in green industries, and it is expected that the number will reach 250,000 units in 2020 and most of them will be involved in bioenergy industry. Green jobs are activities characterized by previously evaluated risks but with a different scope and exposition in connection with newly applied technology [5]. However, it is important to complete an evaluation process with respect to new or re-emergent risks in the biorefineries [6]. The transformation of such plants, from only agricultural and livestock to energy production, introduced a different risk profile for the operators. This aspect is generally underestimated for occupational health and safety (OHS) management, and the large number of plants maintain the same individual risk evaluation that they followed for the operators before transforming the plant. A European database of accidents (mainly explosions), related to biogas production, has been recently created and data on about 170 accidents have been collected from different literature sources [7]. It is necessary to integrate the OHS issues at an early stage of development of the industrial process [8]. The principal reason behind any OHS risk assessment activity is to undertake a proactive and systematic analysis of health hazards in the workplace in order to appropriate the control measures. The management of OHS must be in accordance with the general principles, which should be applied to control workplace hazards in order to:

risks can be identified such as explosion, fire and biological risks. In connection with used materials, including vegetables, food production residuals and animal biomasses, as well as with the properties of fermentation, biological risk deserves particular attention. Fermentation biomass is rich in microorganisms, including pathogens and opportunistic pathogens, and anaerobic processes could lead to the selection of microbial flora, which can promote the presence of anaerobic microorganisms, for example, *Clostridia*, that initially are less represented [9]. Epidemiological data in the field of workers' exposure to the organic dust showed specific occupational diseases, such as respiratory tract disorders (airways inflammation, bronchitis, asthma); gastrointestinal problems (from nausea to diarrhoea) and skin, eyes, nose and airways allergic reactions. In the 1990s, for example, it was found that gastrointestinal diseases were more common among workers of refuse-derived fuel plants [10]. This chapter presents the results of a work aimed at providing the biogas industry with a practical tool, which is able to protect its workers. Biological contamination, fire and potentially explosive atmospheres are the main hazards referred to the biogas production. On this subject, it is essential to take into account that the typical culture of farming is far enough from industrial approach and therefore it requires clear and useful tools, which are able to address both elements—maintenance and operation. The work has allowed to define technical and organizational measures aimed at preventing and mitigating the hazards. From this analysis, a structured safety checklist has been derived. This checklist is a valuable support for the plant operator to evaluate periodically the actual effectiveness of the overall safety measures and to ensure a safer management

Biogas Production Plants: A Methodological Approach for Occupational Health and Safety...

http://dx.doi.org/10.5772/intechopen.72819

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The adopted method for developing the required tool is based on the well-known checklist approach. At the beginning, the initial events (biological contamination, fire and explosion), which could cause an adverse effect on workers (injuries or diseases), were identified. The next step was focused on identification of measures aimed at preventing the workers from getting affected by a potential 'initial event'. In succession, protection measures were subsequently identified to reduce the 'dose', which is received by the worker exposed to the initial

The 'safety checklist' has been derived from organizational and procedural measures and technical systems. The discrimination of protective and preventive measures are highly valuable to define the safety devices' importance; assess and monitor safety levels and take adequate decisions about training, maintenance schedule and safety investments. The checklist has been divided into three sections referred to as biohazard, fire and explosion risk. Each section reports preventive, protective and managerial measures. The checklist has to be considered as a very important tool aimed at evaluating the actual efficiency of safety measures.

of the biogas plant.

**2. Material and methods**

event. The event mitigation was aimed at:

• minimizing the duration of exposure.

• minimizing the amount of hazardous agent;

• protecting workers from hazardous phenomenon and


Even though biogas plants are considered quite simple in installation, they feature a variety of items. As there are many feedstock types, which are suitable to anaerobic digestion (AD) in the biogas plants (biomass from dedicated crops, vegetable waste, sludge, residues of livestock farming such as manure or slurry, organic fraction of municipal solid waste, etc.), there are various techniques for treating these feedstock types and different digester constructions and systems of operation. This implies the need to carry out a specific risk assessment in order to define risk prevention and mitigation measures aimed at minimizing the impact of biohazard on workers' health. In the biogas production supply chain, various work-linked risks can be identified such as explosion, fire and biological risks. In connection with used materials, including vegetables, food production residuals and animal biomasses, as well as with the properties of fermentation, biological risk deserves particular attention. Fermentation biomass is rich in microorganisms, including pathogens and opportunistic pathogens, and anaerobic processes could lead to the selection of microbial flora, which can promote the presence of anaerobic microorganisms, for example, *Clostridia*, that initially are less represented [9]. Epidemiological data in the field of workers' exposure to the organic dust showed specific occupational diseases, such as respiratory tract disorders (airways inflammation, bronchitis, asthma); gastrointestinal problems (from nausea to diarrhoea) and skin, eyes, nose and airways allergic reactions. In the 1990s, for example, it was found that gastrointestinal diseases were more common among workers of refuse-derived fuel plants [10]. This chapter presents the results of a work aimed at providing the biogas industry with a practical tool, which is able to protect its workers. Biological contamination, fire and potentially explosive atmospheres are the main hazards referred to the biogas production. On this subject, it is essential to take into account that the typical culture of farming is far enough from industrial approach and therefore it requires clear and useful tools, which are able to address both elements—maintenance and operation. The work has allowed to define technical and organizational measures aimed at preventing and mitigating the hazards. From this analysis, a structured safety checklist has been derived. This checklist is a valuable support for the plant operator to evaluate periodically the actual effectiveness of the overall safety measures and to ensure a safer management of the biogas plant.
