Dry Cleaning's Dirty Secret: Air Pollution Culprit

Dry cleaning is a common business in cities, towns, and urban areas in the United States and Canada. However, it contributes to air pollution through the release of hazardous air pollutants (HAPs) and volatile organic compounds (VOCs) into the atmosphere. The primary solvent used in dry cleaning, perchloroethylene (PERC), is a toxic chemical that can pollute the air and contribute to smog. It is also a known carcinogen, posing health risks to workers and residents nearby. In addition to air pollution, dry cleaning operations generate hazardous waste, contaminate groundwater, and contribute to soil pollution. The environmental impact of dry cleaning is a growing concern, and efforts are being made to transition to eco-friendly alternatives and implement pollution reduction plans.

The use of PERC/PCE, a toxic chemical that can pollute air, water and soil

Perchloroethylene, or PCE, is a colourless liquid with a sweetish odour that is not flammable under normal temperatures and pressure. It is a widely used solvent, especially in dry-cleaning activities, and is also utilised as a degreaser and in some consumer products such as shoe polish and typewriter correction fluid. PCE is toxic to humans even at very low concentrations and has been linked to serious health effects. Due to its resistance to degradation and biodegradation, PCE can persist in the environment for long periods, leading to soil, water, and air pollution.

PCE is part of a class of chemicals known as halogenated volatile organic compounds (HVOCs) and chlorinated solvents. When PCE is spilled into the environment, it can evaporate and infiltrate the ground, leading to air pollution. It has a half-life of 96 days once oxidised in the air. During its subsurface transport, PCE may be absorbed by soil particles, further contributing to soil pollution.

As a dense non-aqueous phase liquid (DNAPL), PCE is heavier than water and will accumulate at the bottom of water bodies. This creates a secondary source of pollution as PCE continuously dissolves into the water. PCE can travel as a dissolved phase into groundwater and as a gaseous phase, further contributing to water and air pollution, respectively.

The use of PCE in dry cleaning has historically been a significant source of pollution. While modern equipment and preventive measures have reduced accidental spills and leaks, the legacy of past dry cleaning activities still impacts the environment. Residents living near dry cleaning establishments may be at risk of exposure to contaminated groundwater, which can intrude into their breathing air through a process known as vapour intrusion.

Although there has been a push toward alternative, safer chemicals, PCE still accounted for 36% of PCE usage in the US dry cleaning industry as of 1999. The Environmental Protection Agency has established a Maximum Contaminant Level for PCE in water of 5 parts per billion to address this issue. At this low concentration, PCE cannot be perceived by smell or taste. However, dry cleaning operations continue to contribute to air pollution through the release of hazardous air pollutants (HAPs) and volatile organic compounds (VOCs).

The release of VOCs, which contribute to smog and air pollution

Dry cleaning operations emit hazardous air pollutants (HAPs) and volatile organic compounds (VOCs). The main source of these pollutants is the solvent used in the cleaning process, with perchloroethylene and petroleum solvents being the most common. These chemicals are toxic and can persist in the environment for decades due to their resistance to degradation.

VOCs are chemicals that vaporize at room temperature and are released into the air when we use products containing them. They are commonly found in household products such as cleaning supplies, paints, varnishes, and personal care products. Concentrations of VOCs are typically higher indoors than outdoors, and they can contribute to smog and air pollution.

Perchloroethylene (Perc), a suspected carcinogen, is often used in dry cleaning and can be released into the air during the cleaning process. It may also remain on fabrics for weeks after cleaning, off-gassing and releasing VOCs into the air even when the clothes are still in the bag. This contributes to indoor air pollution and can pose health risks to those exposed.

Petroleum solvents, another common choice for dry cleaning, can also release VOCs and HAPs. These chemicals can react with sunlight to form ground-level ozone, commonly known as smog, which has been linked to respiratory issues.

To reduce the release of VOCs and the resulting air pollution, dry cleaners can implement several measures. These include upgrading equipment, converting to closed-loop machines, using refrigerated condensers, and properly training employees to handle and dispose of solvents correctly.

The generation of hazardous waste, which requires proper disposal

The dry cleaning industry generates hazardous waste that requires proper disposal. The main source of pollution from dry cleaners is the solvent used in the cleaning process, with perchloroethylene (PCE) and petroleum solvents being the most common. These solvents are toxic and can contaminate groundwater, soil, and building structures, posing risks to human health and the environment.

The waste products from dry cleaning, including used solvents and contaminated packaging, are often non-biodegradable and can be challenging to dispose of properly. The EPA has estimated that an average dry cleaner can generate over 650 gallons of hazardous waste per year, contributing to long-term environmental damage. The contamination created by dry cleaning stores can pose serious potential risks for real estate investors and lenders due to the strict and costly cleanup standards required for these pollutants.

Historic dry cleaning operations further exacerbate the problem, as they used significantly more solvents, and the equipment at that time resulted in numerous spills and leaks. The legacy of decades of dry cleaning activities is still felt today, with the chemicals used being resistant to degradation and persisting in the environment for extended periods. This has led to concerns about vapor intrusion, where solvent vapors seep into the ambient air and can intrude into people's breathing air, posing health risks to those living or working nearby.

The environmental impact of dry cleaning waste is not limited to air pollution but also extends to water pollution. The California Water Boards found that dry cleaners are a major contributor to groundwater contamination, with wastewater discharges to sewers and septic systems being a leading cause. This contamination can migrate off-site and affect nearby residences, schools, and other buildings, posing risks to human health and the environment.

Proper disposal of hazardous waste generated by dry cleaning operations is crucial to mitigate these risks. While the exact methods may vary based on local regulations and available infrastructure, some common approaches include:

• Implementing pollution reduction plans: Working with local dry cleaners to develop and implement effective plans can help reduce pollution at the source and minimize the generation of hazardous waste.
• Adopting eco-friendly alternatives: Transitioning to eco-friendly dry cleaning methods, such as wet and liquid CO2 cleaning, can reduce the use of toxic chemicals and generate less hazardous waste.
• Compliance with regulations: Ensuring strict compliance with Federal, state, local, and Tribal regulations can help prevent accidental releases of hazardous air pollutants (HAPs) and minimize the environmental impact of dry cleaning waste.

High energy consumption, contributing to carbon emissions and climate change

Dry cleaning is an energy-intensive process, contributing significantly to carbon emissions and climate change. The energy consumption of dry cleaning facilities is a major concern, as the process requires a significant amount of energy to operate the machinery and produce the necessary heat for the cleaning process.

The high energy consumption of dry cleaning is driven by several factors. Firstly, the machinery used in dry cleaning, such as large industrial washers and dryers, consumes a significant amount of electricity. These machines often run on fossil fuels, leading to the release of carbon dioxide and other greenhouse gases into the atmosphere. Secondly, the heating process itself requires a substantial amount of energy. The solvents used in dry cleaning have a high boiling point, requiring a significant amount of heat energy to reach the necessary temperatures for effective cleaning. This heat is typically generated by burning fossil fuels, further contributing to carbon emissions.

Additionally, the energy-intensive nature of dry cleaning is exacerbated by the inefficiencies of the process. Traditional dry cleaning machines often use more energy than is necessary due to outdated technology and a lack of energy-efficient features. Inefficient processes can also contribute to energy wastage, such as when multiple cycles are required to remove stubborn stains. Furthermore, the energy consumption of dry cleaning facilities is often disproportionate to the amount of cleaning they perform. A single dry cleaning facility may serve a large area, resulting in increased energy demands to meet the needs of its customers.

The carbon emissions from dry cleaning facilities contribute to climate change. Carbon dioxide and other greenhouse gases released into the atmosphere trap heat, leading to the gradual increase in the Earth's average temperature. The impact of these emissions on climate change is significant, as the gases can remain in the atmosphere for extended periods, accumulating over time and intensifying the greenhouse effect. The climate change caused by these emissions has far-reaching consequences, including rising sea levels, altered weather patterns, and ecological disruptions that affect a wide range of plant and animal species.

To mitigate the environmental impact of dry cleaning, efforts are being made to reduce energy consumption and transition to more sustainable energy sources. Some dry cleaning businesses are investing in energy-efficient technologies, such as modern machines with better insulation and energy-saving features. Additionally, the development of alternative cleaning methods, such as wet cleaning and liquid carbon dioxide cleaning, offers more environmentally friendly options that reduce the reliance on energy-intensive processes. By adopting these sustainable practices, the dry cleaning industry can play a crucial role in reducing carbon emissions and mitigating the effects of climate change.

The use of petroleum-based solvents, which can release HAPs and VOCs

Dry cleaning operations emit hazardous air pollutants (HAPs) and volatile organic compounds (VOCs), which can contribute to health issues for shop employees, customers, and the wider community. The main source of these pollutants is the solvent used in the cleaning process, with perchloroethylene (Perc) and petroleum solvents being the most common. While regulations limit the amount of emissions from dry cleaners, dangerous releases of HAPs can occur if these regulations are not followed.

Petroleum solvents, in particular, are a concern due to their potential to release HAPs and VOCs. These solvents are complex mixtures of hydrocarbons produced from petroleum distillation fractions that have been further refined. They can be grouped into three categories based on their boiling ranges and solvent strengths: special boiling range solvents (30–160°C), white spirits (130–220°C), and high-boiling aromatic solvents (160–300°C). Exposure to petroleum solvents and the HAPs and VOCs they release can pose health risks, with studies indicating a potential link to Hodgkin's lymphoma.

The use of petroleum-based solvents in dry cleaning can release HAPs and VOCs into the air, contributing to air pollution. These pollutants have been linked to a range of health problems, including respiratory issues. Petroleum solvents are a significant source of HAPs and VOCs, which are released during the cleaning process. HAPs, such as Perc, are known to be potentially carcinogenic to humans, and their use in dry cleaning operations is strictly regulated. However, non-compliance with these regulations can result in dangerous releases of these hazardous substances.

To reduce the emission of HAPs and VOCs from petroleum-based solvents, several measures can be implemented. These include covering containers of solvents to reduce evaporation and fugitive emissions, installing spill containment structures, and investing in closed-loop dry-to-dry machines or innovative cleaning technologies. Additionally, solvent recovery systems, such as refrigerated condensers, can capture and reuse solvents, reducing both pollution and solvent purchase costs. Implementing these practices can help dry cleaners minimize their environmental impact and improve air quality for their employees, customers, and the surrounding community.

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