How dangerous is second-hand smoke?

Second-hand smoke is more than a nuisance—it is a toxic mix of more than 4,000 chemicals.  In 1992 the U.S. Environmental Protection Agency (EPA) classified second-hand smoke as a “Group A” carcinogen. This category is reserved for the most dangerous compounds that have been proven to cause cancer in humans.

In 2006 the State of California added second-hand smoke to its toxic air contaminant list, putting it in the same category as the most toxic automotive and industrial air pollutants. Over 50 cancer-causing chemicals have been found in second-hand smoke, including arsenic, cadmium, benzene and vinyl chloride.

There is no  known safe level of exposure.

Because second-hand smoke particles are so small (less than 2.5 micrometres), they can actually penetrate the alveoli deep in the lungs where oxygen and carbon dioxide are exchanged. Each year in Canada, breathing second-hand smoke causes more than 1,000 deaths in non-smokers from lung cancer and heart disease, and keeps thousands more from leading normal, healthy lives.

The most comprehensive scientific report on the health consequences of second-hand smoke was conducted by the US Surgeon General in 2006 and should be a wake-up call for non-smokers and smokers alike. The US Surgeon General’s Report warns that no amount of second-hand exposure is safe.

Major conclusions from the report reveal that:

  • Second-hand smoke causes premature death and disease in children and adults who do not smoke;
  • There is no risk-free level of exposure to second-hand smoke;
  • Eliminating smoking in indoor spaces fully protects non-smokers from exposure. Separating smokers from non-smokers, cleaning the air, and ventilating buildings cannot eliminate exposures of non-smokers to second-hand smoke.
  1. Second-hand smoke increases risk of heart disease and lung cancer
  • Concentrations of cancer-causing and toxic chemicals are potentially higher in second-hand smoke than in the smoke inhaled by smokers;
  • Chronic exposure to second-hand smoke increases a non-smoker’s risk of developing heart disease by 25 to 30 percent and lung cancer by 20 to 30 percent;
  • Breathing second-hand smoke for even a short time can have immediate negative effects on the cardiovascular system and interferes with the normal functioning of the heart, blood, and vascular systems;
  • Persons who already have heart disease are especially at high risk of suffering negative affects from breathing second-hand smoke. They should take extra precautions to avoid even brief exposure.

2.  Second-hand smoke causes acute respiratory problems

  • Second-hand smoke contains many chemicals that can quickly irritate and damage the lining of the airways;
  • Even brief exposure can trigger respiratory symptoms including cough, phlegm, wheezing, and breathlessness;
  • Persons with asthma or other respiratory conditions are at especially high risk, and should take extra precautions to avoid breathing second-hand smoke.

3.  Exposure to second-hand smoke harms children

  • Babies exposed to second-hand smoke are at a greater risk for sudden infant death syndrome (SIDS);
  • Babies exposed to second-hand smoke have weaker lungs than unexposed babies, which increases the risk for many health problems;
  • Among infants and children, second-hand smoke cause bronchitis and pneumonia, and increases the risk of ear infections;
  • Second-hand smoke exposure can cause children with asthma to experience more frequent and severe attacks.

In addition, findings from a 2009 Canadian Expert Panel on Tobacco Smoke and Breast Cancer Risk confirm that exposure to second-hand smoke can cause breast cancer in younger, primarily pre-menopausal women.

How does second-hand smoke get from one unit to another?

Any way it can!

Due to differences in air pressure between units, floors, and the inside and outside of a building, air is forced through openings, cracks and other leakage paths. The Canada Mortgage and Housing Corporation describes three main “driving forces” that tend to dictate air movement in apartment buildings in the winter months:

  • The “stack effect” causes air to be drawn in from outside at the lower levels of the building, rise up through the floor levels and then leak out of the building at the upper floors;
  • The “wind effect” will cause air to leak into the apartments on the windward side of the building, and flow across the common corridors to the apartments on the leeward side of the building; and
  • Mechanical ventilation systems will also cause the transfer of air to and out of your

Human activity, such as opening and closing windows and doors, and turning on and off fans, also alters air movement patterns.

Air transfer between units is complex–and the solution to minimizing air transfer in one building won’t necessarily work for the next.

Smoking is legal, so don't people have the right to smoke in their own homes?

Yes, in the absence of a no-smoking policy, smokers have a right to smoke in their own homes. However, adjudicators presiding over second-hand smoke cases have come to the conclusion that if the smoke is seriously affecting other tenants or the landlord, the smoker can be ordered to stop or even evicted.

Second-hand smoke has been identified as a breach of reasonable enjoyment at the Ontario Landlord and Tenant Board. just because someone exercises their freedom to smoke does not mean that they haved an absolute right to smoke.

There is no “right to smoke” enshrined anywhere in Canadian law.

Download our article on Human Rights and No-Smoking Policies for Multi-Unit Dwellings.

Do non-smoking tenants have a right to breathe clean indoor air?

Not exactly. There is no “right to clean indoor air” enshrined anywhere in Canadian law.

However, the Residential Tenancies Act, 2006 states that tenants have a right to reasonable enjoyment of their premises, which includes the right to be free from unreasonable disturbances. This could include being free from breathing toxic substances such as second-hand smoke on a frequent and on-going basis.

If I'm getting complaints about second-hand smoke from tenants, and I don't have a no-smoking policy that applies to private units, what can I do?

Consider adopting a no-smoking policy so that you aren’t stuck in a cycle of complaints.

Try to find out where the smoke is coming from, and where it is entering the unit. You can try sealing and caulking cracks and gaps to mitigate the smoke. This will work best if you seal both units: where it is coming from and where it is going.

It is also worth double checking the ventilation system to make sure everything is in working order.

Try talking to your tenant who smokes to see if they might be amenable to smoking outdoors, or in one particular room with the window open, etc. You never know–perhaps this tenant has no idea that the smoke is bothering other tenants in the building.

All tenants are entitled to reasonable enjoyment of their rental units and the premises, including freedom from unreasonable disturbance from other tenants. As the landlord, you are responsible for ensuring that tenants have reasonable enjoyment.

If smoke from one unit is significantly bothering one or more tenants, the second-hand smoke can constitute a breach of reasonable enjoyment. Addressing the issue of second-hand smoke is similar to addressing the issue of loud music. Playing music is allowed in private units, yet when it’s played too loud and interferes with the reasonable enjoyment of other tenants, landlords can take steps to stop this intrusion, including last resort steps to end the tenancy.

Consider adopting a no-smoking policy. Download How to implement a no-smoking policy for a multi-unit dwelling: A protocol for rental housing.

What should I do if people are smoking in the common areas?

As a landlord, you are responsible for enforcing the Smoke-Free Ontario Act. If you actually witness a tenant or tenant’s guest smoking in a common area, inform them that smoking is prohibited by provincial law, and let them know where they can smoke (either inside a private unit if you don’t have a no-smoking policy, or outside). Document this incident for your own records.

Make sure that you have ample no-smoking signage posted around your building. Signs can be obtained from your local public health unit.

If the problem persists, contact your local public health unit and speak with someone in tobacco control. They will investigate the complaint.

You could also write a letter to all tenants informing them of the law and indicating where they are permitted to smoke. Your local public health unit may be able to assist.

What is reasonable enjoyment?

In every tenant and landlord relationship there exists the covenant of the right to reasonable enjoyment, even if no lease is signed. Reasonable enjoyment is the right:

“to take possession, and to be protected against interference with the tenant’s use and enjoyment of the premises by the landlord or others claiming under the landlord” (Bruce Ziff, Principles of Property Law, 3rd ed., 2000).

Section 22 of the Residential Tenancies Act, 2006 states that:

A landlord shall not at any time during a tenant’s occupancy of a rental unit and before the day on which an order evicting the tenant is executed substantially interfere with the reasonable enjoyment of the rental unit or the residential complex in which it is located for all usual purposes by a tenant or members of his or her household.

To be considered substantial, an interference must be so severe that you (or a tenant) are not able to use the premises in a normal way, or in a way you expected when you moved in. In 1976 the Ontario Law Reform Commission established parameters to help determine if reasonable enjoyment has been breached:

  1. Alleged breaches must be committed by the landlord or by someone claiming under the landlord (i.e. another tenant);
  2. Alleged breaches must substantially interfere with the normal enjoyment of the premise; and
  3. Alleged breaches must be more than a temporary inconvenience or a matter or personal annoyance.

There is no concrete list nor universal consensus on what constitutes a breach of reasonable enjoyment, although noise, vibrations, odours, threats, fire, withholding heat, electricity, water, gas, etc. are all common examples. Although a breach can’t be a one-time or isolated occurrence, it doesn’t necessarily have to be continuous but can be intermittent.

For a detailed examination of second-hand smoke and reasonable enjoyment, read Jacob Shelley’s scholarly paper called Environmental Tobacco Smoke as a Breach of the Covenant for Quiet Enjoyment.

What is the Landlord and Tenant Board?

The Landlord and Tenant Board is a quasi-judicial dispute resolution mechanism with exclusive authority to rule on residential tenancy matters as set out under the Residential Tenancies Act, 2006. This law sets out the rights and responsibilities of landlords and tenants who rent residential properties.

One of the Board’s responsibilities is to provide information about the Act to landlords and tenants. In many cases, once landlords and tenants are aware of their rights and obligations they can usually resolve their own problems. However, if a landlord and tenant cannot resolve their problems, then another responsibility of the Board is to resolve these problems for them.

Adjudicators are appointed. Although adjudicators prefer to be consistent, their decisions are not bound by precedent and do not necessarily reflect official Board positions. Decisions are made using the “balance of probabilities” standard of proof, which essentially comes down to a question of credibility–adjudicators must decide whose side of the story is more likely to be truthful.

Could smoking be considered a disability?

In 2007 the Ontario Human Rights Commission held a series of public hearings to examine the issue of human rights and rental housing. It subsequently published a report called Right at home: Report on the consultation on human rights and rental housing in Ontario. On the issue of smoking, the report concluded that “there are conflicting decisions as to whether or not smoking can be considered a disability and whether allowing people to smoke is an appropriate accommodation.”

This issue has been considered a number of times over the years, and Canadian courts and other decision-making bodies have consistently ruled–with one exception–that smoking is not a disability.

The one exception was a British Columbia Labour Relations Board decision in an employment context. Cominco, a nickel smelter, had banned smoking on the plant site, and while the Board found that the ban discriminated against heavily addicted smokers, it also recognized that the employer’s no-smoking policy was reasonable and was adopted to protect non-smokers from a known hazard. The matter was referred back to the parties to resolve how to accommodate the heavily addicted smokers and Cominco’s smoking ban remains in effect today. More on Cominco…

It is important to note that this decision applied to an employment situation. With respect to housing, it is unlikely that an arbitrator or judge would prefer to have tenants be continually exposed to second-hand smoke rather than infringe on someone else’s supposed right to smoke. Just because someone exercises their freedom to smoke does not mean they have an absolute right to smoke regardless of others in the building.

The key issue is nicotine withdrawal. Even if in the future an adjudicator or judge ruled a tenant’s smoking as a disability, the focus then becomes one of reasonable accommodation by the landlord to the point of undue hardship. This could potentially include the provision of an outdoor smoking area, physical modifications to the smoker’s unit or provision of nicotine replacement therapy, etc.

A disability designation is very individual. If an adjudicator were to rule that a smoking tenant was disabled, it does not mean that all tenants who smoke, or all tenants in Ontario, would also be recognized as disabled.

Is there market demand for smoke-free apartments in Ontario?

Adopting a no-smoking policy will provide Ontario landlords with a unique marketing advantage. A 2006 survey of Ontarians living in multi-unit dwellings found that the majority of respondents would prefer to live in a building that banned smoking.

Further, over 80% of Ontarians do not smoke, yet there are few available smoke-free buildings for those who want and need to live smoke-free.

What are the benefits of adopting a no-smoking policy?

Adopting a no-smoking policy is good for the health of residents, and good for business:

  • Reduce maintenance, repair and clean-up costs;
  • Reduce the risk of fire;
  • Reduce complaints about second-hand smoke; and
  • Provide your tenants with a unique amenity.

Check out our benefits section for more information.

Are no-smoking policies difficult to enforce?

No. A no-smoking policy is just like any other policy or rule.

Existing tenants who smoke will be grandfathered, meaning they will be permitted to continue smoking in their units for as long as they choose to live there. New tenants signing new leases will enter into their agreements fully aware (and likely fully supportive) of the policy. Prospective tenants who do not like the policy have the choice to seek accommodation elsewhere.

Plus, enforcing a no-smoking policy will likely be a lot less time consuming than mediating disputes between smokers and non-smokers when there is no policy in place.

For more information, visit our section on enforcement of no-smoking policies.

Are there smoke-free buildings in Ontario?

Yes, but they are still relatively rare. Unfortunately, many landlords and property managers are still under the impression that no-smoking policies are either illegal, discriminatory or unenforceable.

However, despite this, there is a growing number of housing providers that are moving forward and adopting policies. Please see our smoke-free housing directory for details.

You can read about some of them in our success stories section.

If you know of any medium or large size landlords that have a no-smoking policy in place, contact us and tell us about it.

Can ventilation or air filters remove second-hand smoke from the air?

Air filters, purifiers and ventilation systems cannot eliminate second-hand smoke, nor can they address the health concerns of exposure to second-hand smoke. Some of the smoke and larger particles from the air may be removed, but they will not remove the smaller particles or gases found in second-hand smoke.

The American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE), the world’s leading association on indoor air quality standards, agrees that there is no acceptable ventilation system that can protect the health of individuals exposed to second-hand smoke.

James Repace, an internationally recognized second-hand smoke physicist, conducted a review for ASHRAE on controlling tobacco smoke. He concluded that “ventilation technology cannot possibly achieve acceptable indoor air quality in the presence of smoking, leaving smoking bans as the only alternative.”

There is a useful fact sheet about ventilation by the Centres for Disease Control

Are there provincial or municipal laws that prohibit smoking in multi-unit housing?

Yes. Under the provincial Smoke-Free Ontario Act, smoking is prohibited in the common areas of public places (which includes your apartment building) including the corridors, elevators, laundry rooms, etc.

Municipal governments can restrict smoking in public places within their geographic limits and to create smoking bylaws that exceed Ontario’s smoke-free legislation. There are some Ontario municipalities that have passed bylaws prohibiting smoking within a certain distance from doorways.

Contact your local municipality to find out if any such bylaws apply to your building, or visit the Non-Smokers’ Rights Association  for more information.

Municipalities involved in the provision of social housing can create policies to prohibit smoking in private units. The Region of Waterloo is the first municipality in Ontario to prohibit smoking in its social housing private units (effective April 1, 2010), and the ban includes a 5 m buffer zone around entrances.   Since then,  many have joined them.  See our Directory for more information.

Is there support for tenants who want to quit smoking?

A great place to get started is the Canadian Cancer Society’s Smokers’ Helpline at 1.877.513.5333. You can also visit the Smokers’ Helpline online at

For more information, visit our cessation section.

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