Some Lessons From the Horton School – January 2, 1999 – archive

CASLE executive toured the new Horton School in November of 1998, and were very impressed. This is an exceptional facility that can make all those involved proud of their accomplishment. In the spirit of learning from all that we do, CASLE offered to provide our impressions from an Indoor Environment Quality point of view.

We hope these comments will be useful in the ongoing effort to provide our Province’s children and school staffs with the safest and healthiest schools possible. We hope our input will be reflected in the decisions made in the scheduled building of the Province’s next new schools.


  • The stated goal: “To make the air quality inside better than the outside” is commendable because clean air is key to the health of building occupants.
  • The impressive HVAC system uses a three stage filtering system including HEPA filters as well as carbon filters.
  • It is a very positive step that the operating standards exceed the ASHRAE guidelines.
  • We noted a separation of the intake and outtake vents on opposite sides of the building and not downwind.
  • We were also pleased to find that the air system was enclosed within pipes (did not use ceiling plenums for exhaust or delivery), and
  • that most lined ducts were either in return air pipes or prior to the filtering system in the intake section. We did not clarify the type of lining used. Some kinds are difficult to clean, and some encourage mould growth if condensation or other moisture problems develop. Insulation particles may also break away from the lining and enter the airspace.
  • We are very pleased that there is no recirculating of used indoor air.
  • We were pleased to see the technical equipment isolated from the building proper, and in a roomy and easily accessed penthouse. This improves access for monitoring and maintenance and should
    guarantee efficiency and longevity of equipment.

Concern: Even with such a good ventilation system, the strong odour of fresh building materials was evident throughout the building. We neglected to inquire if the janitorial closets are well ventilated.


  • We were pleased to see ceramic tile used in the foyer and major hallways. This tends to be a safe flooring material for asthmatics and environmentally sensitive individuals (although the cement and grouting materials can cause problems if not well chosen).
  • We were also extremely pleased to see that there was no carpeting in the school.
  • Concern: Elsewhere in the school, was soft vinyl tile used? Was the rolled flooring in some classrooms also soft vinyl?
    Hard, more stable (from a VOC point of view), composite tiles tend to be preferable to soft vinyl. Newer, low-emission products are becoming available. Also, research has found Terazzo flooring to be very cost effective in the long term, even though initial installation expense is relatively high. Perhaps terazzo could be used in the other new schools.


  • The use of a geo-thermal heating and cooling system is an important positive step in reducing gas emissions that can be harmful to building occupants. An added feature of this system is its ability to provide stable heat, as well as air-conditioning and dehumidification when needed. Stable thermal comfort is much needed in many existing schools across the Province.


  • We were pleased to see that the roof was not constructed of asphalt, and the drainage system seems extensive. Flat roofs tend to be an area of concern considering the Maritime climate, so we will watch with interest to see how this EPDM roof performs. It is a synthetic rubber which is getting good reviews from the environmental building industry. Tar pots, which cause so much problem in so many schools, will not be an issue at Horton.


  • Large windows provide adequate sunlight (and a spectacular view!). Even the studio classrooms which were in the middle of the hallways appeared to have a feeling of window space. (Would the exposed “aquarium” effect in these rooms be disconcerting?)
  • The positioning of the skylight above the cafeteria area also provides extra lighting.
  • It was good to note that many of the windows are operable, as air other than that supplied by the HVAC system may be needed from time to time.
  • We were pleased to learn that low-e windows were not used.

Concern: However, the sunny side apparently has tinted windows, which may not be a healthy idea according to the CMHC Research Division.

  • The use of electronic ballast lighting with cool-white lights is welcome, as this type of lighting is known to be more beneficial to health and performance than are other types of fluorescent lighting.


  • The acoustics seemed to be good throughout. We were impressed that one could not hear any noise from the gymnasium from the hallway.

Additional positive features were:

  • the use of white boards; (CAUTION, The pens used with these boards can be significant contributors to IAQ problems. Great care needs to go into pen choices or the whiteboards may be more of a liability than the chalk board dust.)
  • low emission, strong gypsum board;
  • low emission paints and gym floor varnish (except for an apparent problem with the final coat which is being investigated. Finishing floors while school is in use, even with the less toxic alternatives is not a good practice. The less toxic products still offgas solvents that should not be breathed in, although they are a significant improvement from oil based products.)
  • ceiling tiles in the vestibules that were clipped to prevent up and down movement that could have produced breathable particles;
  • cork bulletin boards that did not appear to be offgassing.
  • The separation of higher pollution-generating areas such as laboratories, gymnasium, performance theatre and music rooms from other classrooms is a good feature;
  • this includes the locating of the technical room (for heat, ventilation, and other operations systems) in a rooftop penthouse, and generally separate from the building proper, yet fully accessible for maintenance.

Note: When housing the back-up heating system in the same room as the ventilation equipment, it is important to ensure that contaminated ambient air around the furnace burners can not enter the ventilation system.

  • The use of CO2 monitors is an important feature in particular when using propane gas stoves.

Areas of concern:

  • We felt that the building had not had time to offgas properly. Building material odours were strongly evident upon our entering the building, and were higher and lower in various locations during the tour. In particular, the gymnasium was still off-gassing strongly. The performance theatre and a stairwell that had been painted the weekend prior to our visit were filled with airborne chemicals, but the areas were fairly well isolated from the rest of the building. The ongoing construction, and work of plumbers on the various water fountains, etc, were obvious sources of pollution, but the offgassing of the finished walls etc. may or may not have been contributing.
  • We were particularly concerned with the use of propane stoves in the cafeteria and foods labs. Natural gas and propane can cause many health problems in both sensitive and healthy individuals. These problems stem partly from acute, higher, accidental exposures, but also from long-term exposure to low-level combustion and/or gas leakage. One of the first things Environmental Health physicians check for is the presence of gas appliances in homes or workplaces of their patients, and removal is recommended. A U.S. study of 47,000 people with Environmentally Induced Illnesses found Natural Gas to be the primary cause of onset of illness.
  • Pressure treated wood was used on the spectator stands at the sports field. This type of wood can pose a health threat. It has been banned for use in the Yarmouth Parks & Recreation Department, and many other places. Safe alternatives are available.
  • We were disappointed to see that the cupboards and many desks and tables were built of pressed wood and wood laminate. Due to offgassing of formaldehyde and other chemicals, from the glues and binders, these products can contribute to indoor air pollution and pose an unnecessary potential health risk. We look forward to increased availability of low-emission manufactured boards. We were pleased to see metal shelving in the library and some other areas.
  • Plastic furniture also contributes to indoor air pollution. Some fewer schools in the Province have predominantly solid wood fixtures and furniture. CASLE would encourage the use of wood and metal for furnishings.
  • We prefer to see window blinds made of metal instead of vinyl. The blinds in classrooms at Horton were off-gassing quite strongly.
  • We do not encourage buses and other vehicle delivery to circle schools, as classroom windows can be opened and allow vehicle exhaust to enter. We were pleased to hear that bus drivers had been instructed to shut off their vehicles when delivering and picking up students, however the fresh air intake was on the side the of the building where this delivery was happening.
  • We learned that protection from electromagnetic fields was minimally considered. This is in regard to the placement of computers to minimize exposure to students at or near the computers and their monitors, but also from exposure to internal building wiring. There is information available on wiring buildings to minimize EMF exposures.
  • We were surprised to learn that the school is not involved in or encouraging a Fragrance-Free Policy. Fragrance chemicals can significantly add to indoor air pollution even with a good ventilation system.
  • We were surprised to see the types of cleaning products that were in use. Many of these products contain hazardous chemicals. It is of interest to note that the Halifax Regional School Board stopped using these very same products several years ago. This is also surprising because the Annapolis Valley School Board is known to be leading the Province in many Indoor Air Quality issues, and we understood it had very good guidelines in place for using less-toxic cleaning materials. How is it that Horton is not covered by these protective guidelines?

We trust that these products will be replaced soon with less toxic alternatives, and that the same mistake will not be made in the next new schools. The ECOLOGO program from Environment Canada provides an excellent way of choosing least toxic products. Call 613-247-1900. It is recognized internationally as being one of the best ecolabelling programs in the world.

In closing, a reminder that Indoor Air Pollution can and does make some people sick, that even low levels of common indoor air chemical pollution have been found to negatively affect even normal healthy adult’s behaviour and the ability to perform/learn. Learning at optimum levels is important in the school setting, and children tend to be more vulnerable than adults to toxins in the environment.

The designers and builders can be proud of the Horton School. By this time next year the Horton School should be one of the healthiest places for learning in the Province. CASLE encourages the decision-makers of the Province to use all of the lessons from Horton school in the building of the next new schools – to attempt to repeat the successes and to adjust the rest.

Also, to use what we have learned at Horton in the renovation of the many other older schools that are in need of upgrading.

Thank you for this opportunity for CASLE to give input into the important process of providing safe and healthy learning environments for our Province’s school children.

Citizens for A Safe Learning Environment (CASLE)