**8. Potential health effects**

The photovoltaic industry, with its ambitious goal to provide clean electricity, paradoxically uses materials and/or manufacturing processes that are not free from inherent potential health and safety effects. The sector is therefore facing a dual objective: increase energy efficiency and reduce or even abandon processes that use potentially toxic compounds.

Photovoltaic Conversion: Outlook at the Crossroads

(Fraunhofer Institute, 2010; NGI, 2010).

temperatures between 750 and 900°C.

sulphuric acid (Vest, 2002).

**9. Environmental impacts** 

(Electric Power Research Institute, 2003; SVTC, 2009).

2011b).

nanotechnologies (Peyrot et al., 2009; Werlin et al., 2011).

damaging thus high cytotoxicity is suspected (Su et al., 2010).

Between Technological Challenges and Eco-Strategic Issues 327

Institute [NGI], 2010). These concerns also include emerging CdTe and CdSe-based solar

The other element worth considering is the limited number of manufacturers using CdTe, which limits the scope of studies based mainly on data supplied by the manufacturers. The sector handling cadmium salts suffers from a confusion of nomenclature (Classification & Labelling [C&L]) since the physical and chemical properties of Cd salts are quite different from Cd just as the nanoparticles of cadmium salts differ from Cd salts in a thin layer

However, this controversy does not seem to have influenced the Council of the European Union, which will maintain exception concerning Cd use in PV modules in RoHS (Restriction of Hazardous Substances) so that the ambitious targets set by the EU for renewable energy and energy efficiency can be achieved (Council of the European Union,

Nevertheless, current data attribute a lower acute toxicity to CdTe than to elemental Cd (Zayed & Philippe, 2009). Toxicity studies of CdTe nanoparticles are contradictory and inconclusive at this time although the nanocrystals' small size would be a priori more

During the operation of CdTe solar panels, the risk of emission in case of breakage or fire would be considered negligible (Steinberger, 1997, as cited in Nieuwlaar & Aselma, 1997; Fthenakis, 2003; Fthenakis et al., 2005b, Raugei & Fthenakis, 2010). Optimistic findings concerning the risk of CdTe emission in case of fire should be reviewed since, although established according to standard procedures, they were provided on the basis of flame

However, in building fires where temperatures in the thermal plume are between 600 and 1,000°C, those in the flame can reach 2,000°C (Fraunhofer Institute, 2010; Gay & Wizenne, 2010). Since the risk of emission in case of accident is not clearly defined, better protection of

The dismantling and recycling of PV systems can be problematic because of the potential risks associated with handling hazardous toxic compounds, especially polybrominated diphenyl ethers (PBDEs) used as flame retardants including inverters incorporated into photovoltaic systems (SVTC, 2009). The potential toxicity of PBDEs such as the carcinogenic

Other major health concerns inherent in the PV industry are to be considered in the tally of potential risks to human health. These are the risks associated with manufacturing and recycling processes for lead batteries, which involve handling a number of hazardous compounds such as, in addition to lead, heavy metals harmful to the central nervous, endocrine and cardiovascular systems, sodium nitrite, sulphur dioxide, arsenic and

Throughout the life cycle, the PV industry can generate potentially toxic compounds, either during normal production or during accidental situations that could be released into the atmosphere, in solid or liquid effluents. The possible consequences would include alterations in the quality of the air, the soil and the water, with potential impacts on biota

workers responsible for installation and maintenance of PV systems is required.

risk due to bioaccumulation in the body is not yet clarified (ATSDR, 2004).

Health concerns date back to the 1960s (Neff, 1979) and many frameworks have been developed since. The integration of PV panels into the European Waste Electrical and Electronic Equipment directive also shows awareness of PV systems potential toxic waste, which is classified as electronic waste (Silicon Valley Toxics Coalition [SVTC], 2009; Council of the European Union, 2011a). Legal frameworks such as the European REACH directive (Registration, Evaluation, Authorisation and Restriction of Chemicals) have lent support to the trend. As a whole and regardless of the technology, potential risks are a reality that must be addressed thoroughly, without invoking the environmental benefits to delay the risk assessments and possible adoption of mitigation measures.

The solar-grade silicon industry involves potential risks primarily during the manufacturing phase. However, mining of quartz or sand, precursors of metallurgical-grade silicon, also presents various risks mainly due to chronic exposure to crystalline silica dust, causing diseases of respiratory and urinary systems, arthritis, scleroderma and even lung cancer (International Agency for Research on Cancer [IARC], 1998; Yassin et al., 2005).

Developing solar-grade silicon from metallurgical-grade silicon through the Siemens process, which is still the most common in the sector despite the existence of other nonstandardized techniques (Miquel, 2009), releases chlorosilanes especially silane gas and silane tetrachloride (SiCl4). Silane gas is extremely explosive, which is potentially dangerous both for workers and the community surrounding manufacturing sites. Fatal explosions have been reported in Germany (1976), Taiwan (2005) and India (2007) (Ngai, 2010).

As for SiCl4, it is a potent eye and lung irritant that can also affect the central nervous system. It reacts with water and can lead to skin burns and no carcinogenicity or reproductive toxicity studies have been performed so far (Right To Know, 2010). This same gas is the cause of various irritative symptoms observed in the residents of a Chinese village in the Henan province, some 50 meters from a polycrystalline silicon cell plant (Cha, 2008). Cutting solar-grade silicon ingots into plates exposes workers to silica dust (kurf) that can induce breathing problems due to overexposure despite the use of protective masks (Yassin et al., 2005). Other non specific chemicals are also involved in the manufacturing process including sodium hydroxide, sulphuric acid or hydrofluoric acid, and pose potential risks to workers.

It is therefore important for the following two priorities to be applied in order to adjust the accelerated development of the market: a) review the manufacturing processes for emission-reducing technology (abatement technologies), b) carry out or complete the appropriate risk analyses of all potentially toxic compounds with great transparency from manufacturers.

In terms of potential risks to public health, thin film technologies are no exception. The risks are still poorly documented for copper indium selenide and its alloy copper indium gallium selenide but two compounds that are particularly irritating to eyes and lungs are still being handled, namely hydrogen selenide and selenium dioxide (Agency for Toxic Substances and Diseases Registry [ATSDR], 2003). Indium is also problematic as it can induce various diseases including lung cancer and reprotoxic and embryotoxic effects and remains without a standard toxicological reference value (Nakano, 2009).

Technologies using cadmium telluride (CdTe) generate some controversy for two main reasons: a) the presence of cadmium (Cd), a metal classified as a group 1 carcinogen by the International Agency for Research on Cancer (IARC, 1997) and b) little documentation exists about the extent of their particularly chronic potential toxicity (Norwegian Geotechnical

Health concerns date back to the 1960s (Neff, 1979) and many frameworks have been developed since. The integration of PV panels into the European Waste Electrical and Electronic Equipment directive also shows awareness of PV systems potential toxic waste, which is classified as electronic waste (Silicon Valley Toxics Coalition [SVTC], 2009; Council of the European Union, 2011a). Legal frameworks such as the European REACH directive (Registration, Evaluation, Authorisation and Restriction of Chemicals) have lent support to the trend. As a whole and regardless of the technology, potential risks are a reality that must be addressed thoroughly, without invoking the environmental benefits to delay the risk

The solar-grade silicon industry involves potential risks primarily during the manufacturing phase. However, mining of quartz or sand, precursors of metallurgical-grade silicon, also presents various risks mainly due to chronic exposure to crystalline silica dust, causing diseases of respiratory and urinary systems, arthritis, scleroderma and even lung cancer

Developing solar-grade silicon from metallurgical-grade silicon through the Siemens process, which is still the most common in the sector despite the existence of other nonstandardized techniques (Miquel, 2009), releases chlorosilanes especially silane gas and silane tetrachloride (SiCl4). Silane gas is extremely explosive, which is potentially dangerous both for workers and the community surrounding manufacturing sites. Fatal explosions

As for SiCl4, it is a potent eye and lung irritant that can also affect the central nervous system. It reacts with water and can lead to skin burns and no carcinogenicity or reproductive toxicity studies have been performed so far (Right To Know, 2010). This same gas is the cause of various irritative symptoms observed in the residents of a Chinese village in the Henan province, some 50 meters from a polycrystalline silicon cell plant (Cha, 2008). Cutting solar-grade silicon ingots into plates exposes workers to silica dust (kurf) that can induce breathing problems due to overexposure despite the use of protective masks (Yassin et al., 2005). Other non specific chemicals are also involved in the manufacturing process including sodium hydroxide, sulphuric acid or hydrofluoric acid, and pose potential risks to

It is therefore important for the following two priorities to be applied in order to adjust the accelerated development of the market: a) review the manufacturing processes for emission-reducing technology (abatement technologies), b) carry out or complete the appropriate risk analyses of all potentially toxic compounds with great transparency from

In terms of potential risks to public health, thin film technologies are no exception. The risks are still poorly documented for copper indium selenide and its alloy copper indium gallium selenide but two compounds that are particularly irritating to eyes and lungs are still being handled, namely hydrogen selenide and selenium dioxide (Agency for Toxic Substances and Diseases Registry [ATSDR], 2003). Indium is also problematic as it can induce various diseases including lung cancer and reprotoxic and embryotoxic effects and remains without

Technologies using cadmium telluride (CdTe) generate some controversy for two main reasons: a) the presence of cadmium (Cd), a metal classified as a group 1 carcinogen by the International Agency for Research on Cancer (IARC, 1997) and b) little documentation exists about the extent of their particularly chronic potential toxicity (Norwegian Geotechnical

(International Agency for Research on Cancer [IARC], 1998; Yassin et al., 2005).

have been reported in Germany (1976), Taiwan (2005) and India (2007) (Ngai, 2010).

assessments and possible adoption of mitigation measures.

a standard toxicological reference value (Nakano, 2009).

workers.

manufacturers.

Institute [NGI], 2010). These concerns also include emerging CdTe and CdSe-based solar nanotechnologies (Peyrot et al., 2009; Werlin et al., 2011).

The other element worth considering is the limited number of manufacturers using CdTe, which limits the scope of studies based mainly on data supplied by the manufacturers. The sector handling cadmium salts suffers from a confusion of nomenclature (Classification & Labelling [C&L]) since the physical and chemical properties of Cd salts are quite different from Cd just as the nanoparticles of cadmium salts differ from Cd salts in a thin layer (Fraunhofer Institute, 2010; NGI, 2010).

However, this controversy does not seem to have influenced the Council of the European Union, which will maintain exception concerning Cd use in PV modules in RoHS (Restriction of Hazardous Substances) so that the ambitious targets set by the EU for renewable energy and energy efficiency can be achieved (Council of the European Union, 2011b).

Nevertheless, current data attribute a lower acute toxicity to CdTe than to elemental Cd (Zayed & Philippe, 2009). Toxicity studies of CdTe nanoparticles are contradictory and inconclusive at this time although the nanocrystals' small size would be a priori more damaging thus high cytotoxicity is suspected (Su et al., 2010).

During the operation of CdTe solar panels, the risk of emission in case of breakage or fire would be considered negligible (Steinberger, 1997, as cited in Nieuwlaar & Aselma, 1997; Fthenakis, 2003; Fthenakis et al., 2005b, Raugei & Fthenakis, 2010). Optimistic findings concerning the risk of CdTe emission in case of fire should be reviewed since, although established according to standard procedures, they were provided on the basis of flame temperatures between 750 and 900°C.

However, in building fires where temperatures in the thermal plume are between 600 and 1,000°C, those in the flame can reach 2,000°C (Fraunhofer Institute, 2010; Gay & Wizenne, 2010). Since the risk of emission in case of accident is not clearly defined, better protection of workers responsible for installation and maintenance of PV systems is required.

The dismantling and recycling of PV systems can be problematic because of the potential risks associated with handling hazardous toxic compounds, especially polybrominated diphenyl ethers (PBDEs) used as flame retardants including inverters incorporated into photovoltaic systems (SVTC, 2009). The potential toxicity of PBDEs such as the carcinogenic risk due to bioaccumulation in the body is not yet clarified (ATSDR, 2004).

Other major health concerns inherent in the PV industry are to be considered in the tally of potential risks to human health. These are the risks associated with manufacturing and recycling processes for lead batteries, which involve handling a number of hazardous compounds such as, in addition to lead, heavy metals harmful to the central nervous, endocrine and cardiovascular systems, sodium nitrite, sulphur dioxide, arsenic and sulphuric acid (Vest, 2002).
