Are Roofing Shingles Toxic?

Modern roofing no longer uses the highly toxic asbestos of the past. But homeowners still worry about the materials used on their home’s roof construction and how these can affect their families. This is understandable since asphalt shingles contain petroleum-based products. The shingles release dissolved organic carbon into the environment, often entering rainwater running off the pitch. Below, we explore the subject of roof shingle toxicity with insight provided by the pros of

Are roof shingles toxic?

Installation is the time when modern asphalt shingles can be toxic. But after this time, you will generally not experience exposure to harmful chemicals unless you collect potable rainwater from the roof. As the water runs off of the roof, it can pick up chemical toxins from the shingles. An appropriately engineered rainwater collection system can prevent toxins from getting into your potable water.

Otherwise, shingles are not really toxic to you or your loved ones. It is only during the removal of roof shingles that rising dust can contain toxins. If you are having your roof replaced, ask the contractor about your risk and how they remove the shingles to prevent health hazards.

Types of Roof Shingles

There are many types of roof shingles used on homes and commercial buildings today. But most installations use shingles that contain asphalt, the primary culprit in toxicity.

Types of roof shingles include:

  • Organic asphalt
  • Fibreglass asphalt
  • Metal
  • Plastic or rubber composite
  • Fibre cement

Asphalt shingles contain underlayment of polyester or fibreglass. The asphalt is sometimes modified with a polymer or polymer-based coating. Particularly in older homes with roofs not replaced in a long time, you can find fibreglass asphalt shingles.

Which shingles are most toxic?

It is widely accepted in roofing that asphalt-based shingles are the most toxic. But these are only risky during the process of roof installation and removal. It is in construction-related dust and sealants that the greatest toxicity lies. In the commercial roof construction process, many roofers still use heated asphalt, the most toxic method for building a roof.

During construction, other types of shingles can also pose a risk. But each presents its own unique dangers. These shingles types and their associated dangers include:

  • Cedar shakes, a type of roof material that requires treatment with toxic fire retardants that counteract their “non-pollutant” status
  • Asbestos-based shingles, those only installed before government regulation of asbestos, with highly damaging fibres that can cause lung cancer and other diseases

Least Toxic Shingles

Homeowners today want roofers and builders to use materials that do not negatively impact the environment.

Which Roof Shingles Are Least Toxic to the Environment?

Concern about the toxicity of shingle materials goes well beyond the impact that they have on human health. Homeowners also want to be sure that they choose roofing materials that won’t have too much of a negative impact on the environment.

If environmental sustainability is one of your goals for your home construction and roof replacement, consider the points below:

  • Fibreglass and organic asphalt shingles are not sustainable because of petroleum-based materials they contain
  • Fibre cement shingles damage the environment during their manufacture, polluting the air and water
  • Composite shingles of petroleum-based asphalt are the least sustainable, although many companies recycle the materials for use in road construction and similar projects after their use on a residential roof
  • Metal roofs last longer than asphalt, weigh less and work well for rainwater collection system safety
  • Wood shingles are environmentally friendly when sourced from sustainably harvested timber

Making the Right Choice for Your Roof

When looking for the right roof materials for your home, consider that shingles are not necessarily hazardous after installation to your home. The risks involved in exposure to asphalt-based shingles primarily stem from the installation and removal processes or potable rainwater collection. With appropriate water treatment, you can bypass any risks of rainwater collection, even with asphalt shingles.