On this page

1. Introduction
   • VOCs and air pollution
   • VOCs and asphalt
2. Code of Practice objectives
3. Summary of results for 2021
4. Progress since first reporting period (2017)
5. Conclusion & Next steps
6. Contact

List of tables

Table 1: recommended VOC limits

Table 2: Quantities of liquefied asphalt manufactured in 2021 and resulting VOC emissions

Table 3: Products manufactured in 2021 exceeding the Code’s recommendations and resulting VOC emissions

Table 4: Total quantities of liquid asphalt products reported in 2017, 2019 and 2021 and resulting VOC emissions and VOC EI

List of figures

Figure 1: progress of emission intensity towards meeting the 2023 target

1. Introduction

On February 25, 2017, a notice of the issuance and publication of the Code of Practice for the Reduction of Volatile Organic Compound (VOC) Emissions from Cutback and Emulsified Asphalt (the Code) was published in the Canada Gazette, Part I. The Code includes reporting every 2 years from cutback and emulsified asphalt manufacturers. The objective of this progress report is to provide a summary of the data submitted by industry in 2022, for the 2021 calendar year. This is the third progress report following publication of the Code. In this report, results from the first and second progress reports, covering 2017 and 2019 activities, are compared to the 2021 data to assess progress towards meeting the Code’s objectives.

VOCs and air pollution

VOCs are volatile organic compounds that participate in the formation of ground-level ozone through complex reactions with nitrogen oxides (NOx), in the presence of sunlight. They also contribute to the formation of particulate matter via complex chemical reactions involving emissions of other smog precursors, including sulphur dioxide (SO₂), NOx and ammonia (NH₃).

Particulate matter and ground-level ozone are the 2 principal components of smog. Smog is an air quality issue that poses serious health and environmental concerns in Canada. Particulate matter and ozone can be transported by prevailing winds over long distances, making them not only a local urban issue but also one that can extend into many smaller communities and rural areas. The 2013 Canadian Smog Science Assessment (co-authored by Environment and Climate Change Canada and Health Canada) concluded that both particulate matter and ground-level ozone need to be treated as having no safe levels.

VOCs and asphalt

Cutback asphalt and emulsified asphalt are liquefied asphalt products used in various road construction, maintenance and repair applications, such as plant mix, road mix, surface treatment and maintenance mix. These products are prepared by mixing asphalt cement with a petroleum solvent to produce cutback asphalt, or with emulsifiers and water (and sometimes a small amount of petroleum solvent) to produce emulsified asphalt. During paving operations, the petroleum solvent or the water evaporates after the liquefied asphalt is applied, leaving the asphalt cement behind. This evaporation of petroleum solvent results in VOC releases into ambient air. The use of cutback asphalt generates more VOC emissions than emulsified asphalt, as it contains larger quantities of petroleum solvents.

As of 2016, many jurisdictions in Canada and the United States have adopted practices to reduce VOC emissions from this sector. These practices involve either restrictions on the use of cutback asphalt during the ozone season (typically the summer months); a prohibition of the use of cutback asphalt throughout the year; or limiting the VOC content in cutback and emulsified asphalt products.

2. Code of Practice objectives

The objective of the Code is to protect the environment by reducing VOC emissions from the liquefied asphalt sector by at least 40% over a 6-year period. The Code describes recommended practices that should be implemented to meet the Code’s objectives, including maximum VOC contents by volume of cutback and emulsified asphalt products during and outside of the ground-level ozone season (table 1). This season runs from May 1 through September 30. There are no recommended practices in the Code for emulsified asphalt products used outside of the ozone season.

Table 1: recommended VOC limits

Additionally, the Code recommends manufacturing, importing, selling and using low VOC-emitting alternative products instead of cutback asphalt, and promotes the consideration of low VOC-emitting products during contracting discussions. Consideration should also be given to adding a commitment to follow the Code in contracts issued for paving or maintenance operations in Canada.

3. Summary of results for 2021

A summary of the information received for the 2021 reporting period is presented below. Due to rounding, numbers presented throughout this document may not add up exactly to the totals provided and percentages may not exactly reflect absolute figures.

In total, 9 liquified asphalt manufacturers provided Environment and Climate Change Canada with a report for the 2021 calendar year. Of these, 2 reporters indicated that they had closed operations or had not manufactured any cutback or emulsified asphalt in 2021. As such, data presented in this section is representative of 7 Canadian manufacturers of liquefied asphalt. Data submitted by 1 reporter for 6 cutback products whose VOC contents are not available are not included in this report.

Overall a reported 250.7 kilotonnes (kt) of liquefied asphalt were manufactured in Canada in 2021, generating a total of 4.7 kt of VOC emissions after application. As shown in table 2, most of the liquefied asphalt manufactured in 2021 was emulsified asphalt, representing 87.6% of the total quantity manufactured. Although cutback asphalt represented only 12.4% of the liquefied asphalt quantity manufactured, it was responsible for 54.9% (2.6 kt) of the resulting VOC emissions.

Table 2: Quantities of liquefied asphalt manufactured in 2021 and resulting VOC emissions

Reporters also provided data for each liquefied asphalt product sold or manufactured. A total of 234 liquefied asphalt products were manufactured in 2021. Of these products, 44 had a VOC content exceeding the Code’s recommended practices, representing 12% of the total quantity of liquefied asphalt manufactured and 56.0% of the total VOC emissions (table 3).

Table 3: Products manufactured in 2021 exceeding the Code’s recommendations and resulting VOC emissions

4. Progress since first reporting period (2017)

Not all manufacturers are captured by this report and some manufacturers did not report for each reporting period. As such, emission intensity (EI) expressed in kg per tonne of asphalt is used to evaluate the progress towards meeting the Code’s objective, rather than total emissions.

The following table provides the total quantities of liquid asphalt products reported for 2017, 2019 and 2021, as well as the resulting VOC emissions and VOC EI.

Table 4: Total quantities of liquid asphalt products reported in 2017, 2019 and 2021 and resulting VOC emissions and VOC EI

The graph below shows the overall EI of liquefied asphalt products in 2017, 2019 and 2021, along with the 40% reduction target for 2023, from the 2017 level. For the purpose of comparison, a trendline representing the progress for manufacturers who reported all three years has also been added.

Figure 1: progress of emission intensity towards meeting the 2023 target

5. Conclusion & next steps

The VOC EI of liquified asphalt products has decreased by 8.9% since 2017. Based on the current reduction trend, it seems increasingly unlikely that the Code’s objective of a 40% VOC emission reduction by 2024 from the 2017 level will be met. To reach the objective, there will have to be a substantial increase in the use of lower VOC emitting products in 2023, such as emulsified asphalt.

To ensure that the Code’s objective and requirements are understood, Environment and Climate Change Canada completed an informative campaign for procurement enablers and municipalities as well as a campaign directed to pavers in the spring of 2022. In 2025, Environment and Climate Change Canada will publish a fourth and final progress report on the activities of liquefied asphalt manufacturers covering the 2023 calendar year. If the Code’s objectives are not met, it may be necessary to renew the Code or develop another control instrument to better manage VOC emissions from the liquefied asphalt sector.

6. Contact

If you have any questions regarding this report, please contact the Products Division by email at Produits-Products@ec.gc.ca.