Design and Detailing for
Toxic Chemical Reduction in Buildings

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3.1 Construction Related Chemical Pollution
3.2 Scientific Uncertainty
3.3 Indoor Climate
3.4 The Wider Environment
3.5 Materials
3.6 Benefits of Benign Specification
      3.6.1 Increasing Market Share
      3.6.2 The Triple Bottom Line (environment, economy, community)

 

 
Key Principles

1. Growth in the use of modern building materials, decreased ventilation levels and fluctuating moisture levels have introduced increased levels of allergens in the indoor environment.

2. Poor indoor air quality can have a significant effect on health.

3. Volatile Organic Compounds pose a number of risks to health.

4. Care needs to be taken with all material types and attention given to treatments and processing in product manufacture.

5. Designing with benign materials benefits the environment, economy and community. In some cases, prices may be higher than standard products but it is often possible to make trade-offs, and additional costs will decrease as market share and competition increases.
 

 
3.1 Construction Related Chemical Pollution

Throughout the 20th century – but especially post-war – the construction industry has changed both its construction methods and its building materials. This has contributed to changed heat and moisture retaining capacities of buildings. As a consequence, fluctuations in moisture content in buildings are greater and so are the problems caused by moisture, which serves as a medium for chemical reactions and microbial growth. An increasing dependence on a high content of mechanical services in seeking to mitigate this is also a major cause for concern.

Modern buildings are less well ventilated than in the past (it is not unusual to find air changes of less than one per hour in modern, well insulated buildings). Whilst this is a trend necessary for environmental and energy benefits, it can lead to a build up of triggers in the air and to excessive moisture levels.

At the beginning of the 20th century, about 50 materials were used in buildings. Now, about 55,000 building materials are available, and over half are man-made. [35] There has also been a dramatic upsurge in pollutants such as synthetic chemicals in furnishings, fabrics and finishes.
 

 
Solvents (chemicals commonly used in paints and adhesives).

Risks range from: irritation & headaches to dermatitis, colour blindness, brain damage, cancer and even death.

Possible solvent free alternatives:

• Natural water-based emulsion paint;
• Linseed oil-based gloss paint;
• Avoidance of materials containing or requiring glues, e.g. manufactured wood products, wallpaper;
• Where use of glues is unavoidable, (e.g. for installation of linoleum or rubber flooring) use solvent & formaldehyde free glues;
• Avoidance of timber treatments through detailing.
  

 
There is evidence of a relationship between modern building materials, the increase in indoor allergens and an increase in allergic reaction. [36], [37] Some studies have implicated building materials including PVC, some paints, varnishes, insulation materials, timber treatments and wood composites; many furnishings are also implicated.38 There is increasing evidence of the role that toxicology plays in pre-disposing people to asthma. Evidence is appearing that particulates of elements such as cobalt, nickel, cadmium and mercury have a profound effect on the immune system. [39], [40]

The US Timber industry agreed to phase out use of Copper Chrome Arsenate (CCA) timber treatment, which has been a source of concern, provided that by agreeing to do so they were immune from future prosecution. [41] (and spec.note 17 in Appendix F)

Product information relating to health is usually derived from tests conducted on otherwise healthy people, under laboratory conditions, using the substance in question only. The affects on those potentially most vulnerable to such toxins, such as the elderly, children and the unborn are rarely considered. Also, the risk to health from the ‘cocktail effect’ of the many chemicals present in buildings is very rarely considered, so information on health risks from specific substances may be insufficient.

3.2 Scientific Uncertainty
 

 
“The reason for scientific uncertainty is that the widespread introduction of suspected carcinogens into the human environment is itself a kind of human experiment … The tools of science do not work well when everything is changing all at once!” [42]  
 

There is significant activity at a government level to address concerns about, and to establish controls on, chemicals. However the proliferation of chemicals exceeds the capacity of scientific appraisal methods to assess the impacts. The US national toxicology programme estimated in 1995 that 5-10% of the 75,000 chemicals in current use might reasonably be considered to be carcinogenic. Of these at present we regulate only about 200. Eco-labelling systems are emerging, but cannot give attention to chemical toxicity because the basic testing has simply not been done. Current labelling requirements put the onus of voluntary declaration on the manufacturer.

Defra’s chemicals pages provide a source of information on what the Government is doing to protect the environment and human health from the risks posed by exposure to hazardous chemicals. [43]

Despite the lack of an adequate system of appraisal, designers still have a duty of care to ensure that their specifications are fit for purpose in terms of their performance in a construction. Designers failing to apply the precautionary principle will be at increased risk of liability.

SEDA positively supports material testing and content declaration.
 

 
Legal case Study #2

DuPage County Courthouse v. Hellmuth Obata & Kassabaum

Staff experienced symptoms of SBS shortly after moving into the new courthouse in Illinois, with reports of over 400 occupants suffering from headaches, nausea, dizziness and respiratory irritation.

In March 1992 the building was evacuated with several building occupants requiring ambulances. Later that year, several of the occupants filed personal injury lawsuits against the architect and contractors (including the HVAC contractor) alleging that the design of the ventilation system and presence of VOCs were responsible for the illnesses they were experiencing.

The County also filed a lawsuit against the architects and contractors seeking $3 million for fixing the ventilation system. The County failed to win damages, the final verdict stating the County was responsible, attributing the problems to the measures taken in response to earlier concerns over IAQ including the chemicals used to clean furnishings and alterations to the mechanical systems.

Only minor damages against the architect and contractor were awarded due to faults in the air handling systems. However a number of individual suits were settled out of court.

The publicity that this generated played a key role in insurers and others taking SBS more seriously.
 

 
3.3 Indoor Climate

It has now been demonstrated that the contemporary indoor environment is a significant source of risk in relation to health. In a study of 15 office buildings in Copenhagen, it was found that only 12% of the pollution of the internal air originated in the occupant metabolism:- 25% derived from smoking, 20% from materials & furnishings and 42% from the ventilation equipment. The basis of this work was the complex ‘olf’ unit - invented by Fanger for the amount of pollution into the indoor climate emitted by an average adult. Much that followed from it transformed perceptions of the impact of the indoor environment on health, and has major repercussions in relation to behaviour, servicing strategies, choice of finishes and legal requirements.
 

Figure 1: Average Pollution Sources in 15 offices in Copenhagen.
An average of 17 occupants worked in each office. Source: P O Fanger. [44]

 
More recent studies have identified that concentrations of more than 35 VOC’s [including vinyl chloride, benzene, formaldehyde and toluene] are typically up to 10 times higher indoors than outdoors. [45] They are associated with a wide range of detrimental health effects in humans and animals, [including cancers, tumours, irritation and immune suppression]. Many have been identified as emanating from building products. The WWF study (referred to above) found many instances of fire retardant in human blood and tissue samples. Exposure limits are often set for the work environment, but there are no controls to limit exposure to harmful agents in the home. Given the time we spend in domestic buildings, pressure is building to address this.

There is a clear connection between VOC concentration in the air and indoor temperature. The higher the temperature, the more VOCs appear in the gaseous phase. It has also been shown that concentrations of many VOCs increase as humidity falls. [Though this is not the case for formaldehyde]. Information is available on sources of VOCs, the extent of emissions and assessing indoor air quality, although avoidance is the best strategy. [46]

Nobody in the UK yet markets a formaldehyde-free particleboard. OSB uses less resin binder than particleboard due to the removal of fine particles. Some OSB has less formaldehyde emission than particleboard (2 to 4.5 mg per 100g as against 3 to 7 mg per 100g) because the binder used is the more stable phenol formaldehyde, and is locked in. Particleboard uses the less stable urea formaldehyde. Both products meet the class E1 requirements of BS EN 300 1997, but a readily available UK “living board” as currently manufactured in Germany is awaited. There is a variation of emission with temperature.

A number of schemes are now in place for classifying low emission rates. There is presently no limit for VOC emissions in the European Product Standard, although schemes exist in a number of countries and there are plans to introduce a scheme. Recent research indicates that indoor air moisture content can best be tackled with the right choice of materials and surface treatment. [47]
 

There is evidence to suggest that adequate ventilation can reduce the impact of allergy triggers existing in the home. Also, appropriate choice of low emission materials helps to reduce the off-gassing that contributes to poor indoor air quality and triggers allergenic reactions. It can therefore be compatible with reducing ventilation requirements. This is an accepted trade off under the Norwegian building regulations. [48]
 

 
VOCs
Volatile organic compounds are chemicals that are emitted as gases from certain solids or liquids at room temperature. There are 50 – 300 chemicals that can be classed as VOCs in the average indoor environment. The main sources in domestic environments are paint, floor sealant, vinyl and furnishings.

VOC levels have been shown to be a lot higher during and after construction. This is often apparent in the smell of a new building, or where a new carpet has been fitted. Off gassing of the VOCs from the materials may occur over a prolonged period of time. Formaldehyde is the most common VOC in indoor air, and is emitted from carpeting, particleboard, furniture and new clothing. It is colourless but has a distinctive odour. Certain VOCs, such as formaldehyde, are often absorbed onto surfaces and textiles reducing peak concentrations but prolonging overall exposure. The most vulnerable are pre-toddler infants, who spend significant amounts of time in close proximity to the floor.

Exposure to VOCs is primarily though inhalation, although some VOCs are ingested through food, or liquids. Exposure to VOCs can result in irritation to the nose, throat and eyes; they can cause headaches, nausea, dizziness, and can aggravate asthma. Chronic health effects linked to VOC exposure include cancer, liver damage, kidney damage and central nervous system damage. The majority of studies have focussed on occupational exposure, where VOC levels are often higher and on the impact of one specific chemical over a relatively short period. Little is known about the effect of combined exposure or of the effects of low level long term exposure. It has been repeatedly shown that working as a painter increases the risk of lung cancer by 40% - however, it has not been possible to identify the causative chemical due to mixed exposures. [50]

Common VOCs are listed below:

• Formaldehyde	• Benzene	• Toluene
• Methylene	• Chloride	• Xylene
• Ethylene glycol	• Texanol	• ß1,3-butadiene

There is some information connecting the use of plastics in the home and respiratory illness. A Finnish study that investigated the presence of PVC based wall materials in the home and the respiratory health of children indicated that there might be adverse health effects on the lower respiratory tracts of small children from emissions from indoor plastics. [51] It also concluded that there was an increased risk of pneumonia in children exposed to plastic wall materials.

Many of the water based paints used in the home still contribute small amounts of VOCs to the indoor environment and have been linked to the exacerbation of asthma systems. Due to these medical concerns a number of ‘VOC free’ paints have appeared on the market.

Formaldehyde

Formaldehyde is present in significant quantities in a wide range of house furniture, insulation and floor and wall fittings. It is used in hundreds of industrial processes including the manufacture of particle boards, MDF, chipboard and plywood, thermal insulation foams, adhesives, glues and resins.

A study into the domestic exposure of young children to formaldehyde in Australia suggested that it increases the risk of childhood asthma. [52] An Austrian report distinguishes between the levels perceived as safe for occupational exposure and the levels that should be present in the home – infants spend a large portion of their time indoors. [53]

Risks

• Exposure to high levels or long-term low levels of formaldehyde may cause cancer (emissions still occur after installation).
• Formaldehyde is recognised as an asthma trigger.
  
  Possible formaldehyde alternatives:

• Cellulose insulation in lieu of foamed insulation;
• Water-based paint in lieu of wallpaper and associated glues;
• Timber in lieu of MDF and chipboard (Note: timber naturally contains formaldehyde, but at levels that are acceptable in terms of minimum health risk).

  
3.4 The Wider Environment

Many products used in construction have widespread unregulated environmental impact. Those containing VOC’s for example impact on the ozone layer and there is a wide range of water, air and land impacts from many substances in common use. The most serious chemical pollutants include the Chlorinated hydrocarbon pesticides such as DDT, aldrin and dieldrin, the polychlorinated biphenyls (PCBs) that have been used in a variety of industrial processes, and metals such as mercury, lead, cadmium, arsenic and beryllium. All these substances persist in the environment and are toxic to life if they accumulate in any appreciable quantity. Production of PCBs was halted at the beginning of the 1980s because of their accumulation in the food chain, but they are still found today in trace concentrations in the sea and in the fatty tissue of marine animals.

As an example, to demonstrate the range of effects, the subject of leachates is an increasing area of concern and is considered here. [54],[55] The potential adverse impacts on biodiversity are evident. Biodiversity is a key requisite of sustainable development as set out in “Meeting the Needs”. [56] The Scottish Executive is begining to acknowledge the importance of biodiversity as a neglected area in relation to sustainable construction. It is a big challenge, requiring more inter-departmental working, research and policy development to create a feedback loop within the Executive. There is a lack of data on the environmental impact of construction but this area of concern is related to - but outwith - the scope of this publication.
 

 
Leachates
These are apparent in landfill and arise from a wide range of construction materials and products including concrete, plastics, paper and electrical goods. Heavy metals, such as chromium and stainless steel, used in the construction industry manufacturing process, are a particular concern as are treatments and finishes that leach from buildings in use. Another area of concern is the final destination of unrecoverable, non-biodegradable wastes from building sites, such as plastics and plasticisers that release chemicals which are disruptive to ecosystems over time.
 

 
Legal case Study #3

515 Park Avenue, New York

515 Park Avenue is known as the world’s most expensive condominium building, where the cheapest units sell for $8 million and require a $40,000/month maintenance fee. However, cracks in the foundations, poorly insulated pipes and improperly sealed walls allowed water to seep into the building resulting in toxic mould growth. Eight of the building’s 38 apartments had to be evacuated and many common areas had to be sealed off over potential health concerns. Residents and the buildings board of managers started litigation against the building’s sponsors and contractors in late 2002. A second case asking for a phenomenal $2 billion in damages was also filed by one resident against the building’s board of managers as well as against the building sponsors and contractors.
 

3.5 Materials

For the purposes of this study it is convenient to use the system of classification of materials used by Bjørn Berge in “The Ecology of Building Materials”, which identifies materials used in buildings as inorganic, organic and composites of these. [57] The meanings of these terms in this context are explained below and are slightly different from their use in other disciplines.

Inorganic

This group includes many of the most traditional and ubiquitous of building materials that tend to be robust, re-useable or recyclable. Although they may be organic in origin, they are mainly manufactured from materials commonly regarded as minerals and are in a form that is not subject to biological decay. Some (especially the metals) are subject to slow chemical decay.

Many metals and their alloys are subject to leaching by even slightly acidic rainwater and this can give rise to pollution. Many naturally occurring elements can be dangerous and metals are often highly toxic to humans and animals even in small quantities.

These may be present as impurities or as a necessary part of alloys of the commoner metals. Radon emission may be a problem with some of the non-metals and dust may be a problem in the manufacture and use of any of this group.

Lime, cement and their derivatives are corrosive and care is required in applying materials that contain them.
 

 

	Ferrous metals	Secondary metals
Stone	Iron	Arsenic
Earth	Steel	Cadmium
Brick		Chrome
Ceramics		Cobalt
Aggregates		Lead
Glass	Non-ferrous metals	Manganese
Cement	Aluminium	Nickel
Concrete	Copper	Titanium
Lime + Limecrete	Zinc	Gold
Plaster/render		Alloys

 

 
Organic materials

Organic materials in this context are materials which come directly from either plant or animal sources and are subject to biological decay. Some of these are dangerous, but the ones listed here are generally considered healthy and will biodegrade benignly if they have not been over-processed or treated. However, they are often treated with a wide range of potentially dangerous chemicals to prevent decay. Examples of these include organophosphates in wool, weed killer in hemp and tannins in leather.

 

Vegetable products	Animal products
Timber	Hide
Timber products	Hair
Straw	Wool
Rubber	Wax
Linoleum	Glues
Coconut fibre

 
Synthetic materials

Synthetic materials in this context are either not naturally occurring or are naturally occurring but have been subject to significant chemical or mechanical processing. They therefore tend to have significant levels of embodied energy and many are specifically designed to resist chemical and biological decay. Unless clearly certified as benign and environmentally responsible they need to be regarded as needing to be treated with caution. The best current source of information on potential hazards is in “The Ecology of Building Materials”. [58]

 

Plastics	Paints	Solvents
Synthetic Fibres	Preservatives	Formaldehyde
Synthetic Fibre reinforced products	Sealants	CFCs/HCFCs
Industrial by-products	Glues and resins
Fossil oils	Asphalts + bitumen

 

 
Composites

Most building products are composite elements made up of a number of different materials each of which will have different environmental credentials. The use of composite materials in general greatly reduces the possibility/viability of later recycling or re-use. Reinforced concrete is an example. It is possible to separate out the steel but it is noisy and expensive. Earlier floor techniques with, for example, steel beams or brick vault in the compression zone and concrete on top kept the materials separate.

A window will tend to have a large number of different components: timber, glass, glue, aluminium, sealant, gas. The potentially toxic content in all the elements should be a consideration as well as any life cycle issues for maintenance and management.

 
3.6 Benefits of Benign Specification

3.6.1 Increasing Market Share

Environmental issues are increasingly used in specification choices to discriminate between products and frequently only imports are available to meet the required performance specification. Transportation of imports adds to pollution, but this is currently justified by improved performance in the building lifetime. With increasing demand for healthy and energy efficient buildings this is already applying to a small but growing market of whole buildings being imported.

Many environmental products lack competitors and so can be expensive, making sustainable construction potentially more expensive than unsustainable alternatives. If appropriate agencies were to identify readily available and cost effective opportunities for reducing environmental impacts, it would result in a whole range of benefits.

3.6.2 The Triple Bottom Line (environment, economy, community)

Designers and specifiers need to become more aware of benign product choices.

There is an overriding assumption that construction activity is optimized with respect to cost and hence that change imposes an unnecessary burden. (This assumption is challenged in section 5.) This view fails to take account of widespread waste. Reduction in chemical loads should be adopted for the wider economic, social and environmental benefits. If governments are serious about addressing environmental pollution then economic drivers are likely to make this increasingly easy. The convergence of environmental and economic policy is helpful. For example the increasing requirement for recycled materials means that reducing chemical loads will add value should design for deconstruction be more widely adopted.

Specifying healthy materials is a means of cutting unnecessary use of financial resources on, for example, sickness at work, environmental mitigation and remediation issues and enabling money to be spent more productively on other things. Ultimately we all pay for the NHS/health insurance premiums to treat the consequences of building toxicity, and the taxes that are needed to deal with cleaning rivers, bunding landfill and remediation of polluted land. Yet prevention is usually cheaper than cure. (see cost case study 5.5)

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Footnotes:

35. Roalkvam D., (1997) Naturlig Ventilasjon NABU/NFR

36. Andrae S., et al (1988) Symptoms of bronchial hyper-reactivity and asthma in relation to environmental factors Arch Dis Child 63 473-478

37. Abramson M., et al (1991) Ambient Air Pollution and respiratory disease Med J Aust 154 543-551

38. Oie L., (1998) The role of indoor building characteristics as exposure indicators and risk factors for development of bronchial obstruction in early childhood NTNU Trondheim

39. PM2.5 particulates: man-made particles smaller than 2.5 microns. These have in crease dramatically in recent years at least in part due to the shift from coal to waste oil mixes in incinerators, factories, etc.

40. www.epa.gov

41. Lumber Companies agree to Arsenic Ban St Petersburg Times February 13th 2002

42. Steingraber.S (1997) “Living Downstream” Virago Press, London

43. www.defra.gov.uk/environment/chemicals/index.htm

44. Fanger O.L (1998) Hidden Olfs in Sick Buildings ASHRAE Journal

45. www.epa.gov/iaq/voc.html

46. “Volatile organic chemical (including formaldehyde) in the home”, Medical Research Council, Institute for Health and the Environment (2000)

47. Technical University of Denmark (2005) “Moisture Buffering of Building Materials” BYG·DTU R-126

48. National Office of Building Technology and Administration, Norway, Guidelines to the Technical Regulations under the Planning and Building Act (1997) (English version available from: www.be.no/beweb/english/englishtop.html)

49. “Das Gesunde Haus” Hubert Palm, (1968) Verlag Gesundheitsdienst. (second ed. 1974)

50. Lynge, E., Anttila, A. and Hemminki, K., (1997) Organic solvents and cancer. Cancer Causes Control, The Harvard-Teikyo Program Special Issue, Vol. 8, No. 3, pp. 406-419

51. Jaakkola, J.J., Verkasalo, P.K. and Jaakkola, N., (2000) Plastic wall materials in the home and respiratory health in young children. American Journal of Public Health; Vol. 90 pp. 797-799

52. Rumchev, K.B., Spickett, J.T., Bulsara, M.K., Phillips M.R., and Stick, S.M., (2001), Domestic exposure to formaldehyde significantly increases the risk of asthma in young children, European Respiratory Journal Vol. 20 pp. 403-40849. Wankte et al. “Exposure to gaseous formaldehyde induces IgE-mediated…”

53. Wantke, F., Demmer, C.M., Tappler, P., Gotz, M., Jarisch, R., (1996) Exposure to gaseous formaldehyde induces IgE-mediated sensitization to formaldehyde in school-children, Clinical & Experimental Allergy, Vol. 26 Issue 3 pp. 276-280

54. SEPA “State of the Scottish Environment 2006” www.sepa.org.uk

55. Amlo S et al Identification of PCB and decontamination of PCB-containing buildings in Norway.
Andersson, Åse., (2002) Harmful compounds in paint leached from wooden facades, The 3rd International Conference on Sustainable Building, Oslo 2002
Andersson, Åse., (2002) Long-term leaching of environmentally hazardous substances in admixtures, emitted from concrete, The 3rd International Conference on Sustainable Building, Oslo 2002
Christensen, N.T. et al. (2002) Harmful substances in building waste in the future – inventory and prediction of twelve substances. The 3rd International Conference
on Sustainable Building, Oslo

56. Choosing our Future – Scotland’s Sustainable development Strategy (2005)
www.scotland.gov.uk/Publications/2005/12/1493902/39032

57. Berge, B. (2000), The Ecology of Building Materials, Architectural Press, Oxford

58. Berge, B. (2000), The Ecology of Building Materials, Architectural Press, Oxford

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