Are Solar Panels Toxic? [Definitive Guide]

We know that solar panels are good for the environment, but what about their safety?

Many people wonder if they emit harmful substances into the air or ground. In this post, we will explore whether or not solar panels have any negative effects on humans and animals.

The majority of the materials used to make solar panels are non-toxic and safe. This includes glass, plastic, aluminum, and steel. However, a small number of toxic trace materials may be used to improve material properties during the manufacturing process, which is a common industry practice that should not be a cause for concern.

There are so many different solar panel products with different material compositions and there is no clear answer as to whether or not they are toxic.

But here is what you should know about.

A typical solar panel consists of glass (75%), polymer (10%), aluminum (Al) (8%), silicon (5%), and copper (1%). It can also have trace amounts of silver (Ag), Cd, chromium (Cr), Sn, Pb, and other metals that make up a considerable portion of solar panel waste.

When there is physical damage on solar panels or when they are old, certain materials like Ag, Pb, Cd can leach into the environment and contact human skin. So, you should avoid randomly touching old/damaged panels or removing them without taking the proper safety precautions.

Although solar panels have toxic chemicals they are generally is not a toxicity concern during the useful service life of the panels. The toxicity is a concern if proper maintenance and recycling aren't practiced.

The solar panels become a toxicity concern mostly during their post-use period, where they are likely to be disposed of or stockpiled for future disposal.

Let's take a look at each individual component that goes into manufacturing a solar panel in order to better understand its potential effect on humans and the environment.

Solar panel components and their related toxicity concerns

Solar Cells

The most common solar panels are made of silicon, a non-toxic material. However, some less-common solar cells contain other toxic chemicals that may pose a hazard to the environment and humans if not disposed of properly.

One type is cadmium telluride (CdTe). While it can withstand extreme temperatures, this type of solar panel also emits toxic gas when exposed to heat. This is why it's very important to follow the manufacturer’s instructions for proper disposal and recycling after use.

Another rare example of a potentially harmful solar cell is copper indium gallium selenide (CIGS). If broken apart or melted down, it is possible for this material to release harmful levels of lead, selenium, and indium.

The safest solar panels are the most common ones made out of silicon. There may be some toxicity issues with products containing toxic chemicals like cadmium telluride or copper indium gallium selenide (CIGS).

However, it is important to note that these are not commonly used in solar panels. It’s best to check the safety record of a product before making any purchases.

In conclusion, there may be some toxicity issues with less common types of solar cells like cadmium telluride or copper indium gallium selenide (CIGS). However, the majority of solar cells have a non-toxic makeup.

That said, solar panel manufacturers may use Pb to solder copper ribbons that connect each cell in the module. Pb exposure at high concentrations is known to cause serious health problems in children and adults.

However, Pb exposure is only becoming a concern if the panels are broken or disposed of improperly. The improper disposal of PV panel waste with a broken glass layer could endanger human health and the environment and are classified under many governing authorities' standards.

Aside from Pb, researchers have also discovered other elements such as Cr, Mn, Ag, and Cd in trace amounts in the leachate, with increased leachability seen in samples without the glass encapsulation. This tells us proper handling and recycling are important to reduce environmental pollution.

Solar Panel Glass

Another major solar panel component is the glass that encapsulates the solar cells. The most common type of solar panel glass is made of borosilicate or tempered glass. These types of glasses are non-toxic and generally have nothing to worry about in terms of toxicity.

EVA

The EVA sheet is also known as ethylene-vinyl acetate, which is a type of polymer material used to protect solar cells from dust and harsh weather conditions. This material doesn't pose toxical concerns unless it is burned to release gases like vinyl acetate and acetic acid.

Backsheet

The backsheet is the panel's last layer, and it provides both mechanical and electrical insulation while functioning primarily as a protective layer. It is generally made of TPT(Tedlar Polyester Tedlar), PVF (Polyvinyl Fluoride), and PET (Polyethylene Terephthalate).

These types of plastics have been extensively studied and found to be safe for both humans and the environment. They don't pose a direct toxicity risk from solar panels.

However, if these materials are burned, they can release toxic fumes, and their proper disposal and recycling are extremely important.

Silicone Glue

Solar cells are glued to the glass with silicon-based glue. Silicone is generally non-toxic, but some types of silicone may have additional components that have been associated with toxic effects on humans.

That said as a solar panel owner you don't have to worry about the silicone that manufacturers use, since you will not be exposed to wet silicone that can release VOC (volatile organic compounds) like methyl methacrylate and toluene.

Junction Box

Junction Boxes are used to connect solar panels together and protect the wiring from damage. They usually consist of a plastic or metal housing with electrical connections inside. Although junction boxes are considered non-toxic, the electrical connections inside may contain lead.

Lead is a dangerous heavy metal that accumulates in both nature and humans. As a result, the EU has prohibited the use of lead in all electronic products, with the exception of solar cells.

Inverters

Inverters are used to convert direct current (DC) from the solar panels into alternating current (AC). They're usually made out of a metal housing with plastic components, and they may contain hazardous materials like lead.

This is an important component when it comes to safety in terms of toxicity because improper disposal or recycling can increase the risk of environmental pollution.

Panel Frame

The panel frame is the outermost component of a solar panel that provides mechanical strength and supports all other components inside it. Solar panels are usually made out of aluminum, steel, or plastic frames depending on which one performs better in terms of cost efficiency for manufacturers.

These materials are generally safe but depending on the manufacturing processes can include small amounts of other metals to improve material properties. 

Depending on the composition of these added materials they may have a negative impact on the environment and humans. Therefore, it’s best to check with the manufacturer's safety data sheets to know what type of materials are exactly used as the frame material.

Which type of solar panels more likely cause a bigger toxicity risk?

The types of panels listed below may contain toxic substances due to their composition or manufacturing process.

CdTe solar panels

CdTe stands for Cadmium Telluride, which is a semiconductor material that can be used to make solar cells. Generally, it's considered safe but because of the cadmium content, this type of panel could pose toxicity risks if mishandled or disposed of improperly. In particular, cadmium compounds are highly toxic and carcinogenic.

Cadmium is quite often used as a stabilizer of the semiconductor material. It's also often added to some types of solar cells because it reduces electrical resistance, making them more efficient and scalable for mass production at lower costs.

Most everyday electronic equipment still uses Ni-Cd battery chemistry which contains Cadmium as well. But the Cd used in batteries doesn't pose the same toxicity risk since it is housed within the battery and unlikely to get into the environment.

Gallium arsenide (GaAs) panels

GaAs is a semiconductor material that can be used to make solar cells. It contains arsenic, which has been linked with some types of cancer and other toxic effects on humans at certain concentrations in the air or water. As a result, the EU has placed limits on its use of electronic equipment.

Old solar panels (Hexavalent chromium coatings)

Old solar panels may contain hexavalent chromium coatings that were used to increase solar cell efficiency by providing better light absorption.

However, this type of coating poses significant toxicity risks to humans and the environment because it can be easily released into water or air when exposed during recycling, disposal, or salvage activities.

Newer solar panels today have safer alternatives to toxic hexavalent chromium coatings. However, this may be a concern depending on the type of solar panels you're looking at buying.

Thin-film solar panels

Thin-film solar panels contain CIS/CIGS and may be toxic due to copper and/or selenium content. Selenium is considered toxic and can accumulate in aquatic organisms, causing significant environmental damage over time.

RoHS Restrictions on the Use of Certain Hazardous Substances (RoHS) in Electronic Devices

The California RoHS Law was designed after the European Union's (EU) Directive 2002/95/EC, which prohibits the use of certain hazardous compounds in electrical and electronic devices marketed in the EU.

The California RoHS law required the DTSC to adopt regulations prohibiting the sale or offer for sale of a covered electronic device in California if the device is prohibited from sale or offer for sale in the EU due to the presence of lead, mercury, cadmium, or hexavalent chromium above certain maximum concentration values (MCVs). California RoHS standards set by the DTSC went into effect on January 1, 2007.

Any party who sells or distributes a covered electronic device in California is subject to RoHS. This includes manufacturers, suppliers, wholesalers, and retailers that sell items considered covered electronic devices in California.

However, A CED that is not covered by the EU RoHS Directive (for example, a device covered by the end-of-life-vehicle directive or battery directive rather than the RoHS directive) is not subject to California's RoHS law.

Under this directive, the maximum permissible concentration of most restricted materials is limited to 0.1% by weight, with the exception of cadmium, which has a limit of 0.01%.

Conclusion

In conclusion, solar panels generally don't pose a toxicity risk as long as they are manufactured using cleaner material technologies and are handled properly after their life cycle.

If you have solar panels on your roof or yard, you don't have to worry about the toxicity of your panels. However, make sure to properly maintain them by observing their energy performance and visual appearance to detect early signs of damage that can affect electrical operation.

If any of your solar panels seems damaged or has a sign of leakage, then toxicity concerns may arise. Because water and other weather conditions can affect the panel and damage it. In this case, it's best to contact a professional that can handle the situation safely.