Environmental Assessment of Building Materials for Good Indoor Air Quality

Transcription

1 Environmental Assessment of Building Materials for Good Indoor Air Quality Miriam García-González (1), Anna Widheden (2), Sarka Langer (2) (1) Tecnalia Research & Innovation (2) IVL Swedish Environmental Research Institute Ltd VII International Congress on Architectural Envelopes May 27-29, 2015, Donostia-San Sebastian, Spain

2 Building Materials for an envelope Energy efficiency Service life GENERAL DRIVERS Material efficiency Health issues VOC (including formaldehyde) Radon, Particles, Fibres Microbiological attack Impurities from outside and human activity Indoor environment Thermal comfort Acoustic comfort Lighting comfort Odour comfort Indoor Air Quality

3 Indoor Air Quality (IAQ) People spend 85-90% of time indoors and the exposure for air pollutants occurs mainly in the indoor environments Indoor air pollution originates from the building materials, furnishing and human activities WHO has specified IAQ guidelines for selected compounds for the protection of public health The substances of special concern are benzene, carbon monoxide, formaldehyde, naphthalene, nitrogen dioxide, polycyclic aromatic hydrocarbons (especiallybenzo[a]pyrene), radon, trichloroethylene and tetrachloroethylene They have indoor sources, are known in respect of their hazardousness to health and are often found indoors in concentrations of health concern Indoor ozone may react with the emitted compounds to produce new toxic compounds (secondary emissions) Microbiological and mold presence worsens IAQ 2x-10x More pollution indoors than outdoors 160% Childhood asthma rates increased in the past 20 years VOC 6 out of 10 homes are hazardous to their occupant s health

4 Consequences of poor air quality Worsening asthma, allergies, and other respiratory problems Headaches & nausea Shortness of breath Sinus congestion, sneezing and cough Eye, skin, nose and throat irritations Memory loss, dizziness,fatigue and depression For example, working days are becoming less effective and working absence due to illness increases!

5 Analysis of IAQ Pollutants most often measured by established sampling and analytical techniques in indoor air are Volatile Organic Compounds, NO 2, ozone and formaldehyde. Mould is not acceptable in indoor environments The materials are tested for suitability for indoor environments with respect to the VOC emissions according to established assessment schemes The emission pattern may be altered by chemical transformation initiated by humidity or reactive substances such as ozone VOC, aldehydes after 3 days VOC, aldehydes after 28 days Primary emissions Secondary emissions Ozonation VOC, aldehydes before and after Various mould species Microbiological resistance

6 Improvement of IAQ? Active methods HVAC Permeability to water vapour Improved transpirability Avoid moisture Hygroscopicity Passive methods New materials Materials with low emissions Materials that decontaminate Capillarity Not applicable for facades insulated from the ground

7 The Construction Product Regulation (CPR): Basic Requirements Hygiene, health and environment The construction works must be designed and built in such a way that: they will not be a threat to the hygiene or health and safety of people nor have an exceedingly high impact on the environmental quality or on the climate during their construction, use and demolition Particular aspects considered: a) the giving-off of toxic gas; b) the emissions of dangerous substances, volatile organic compounds (VOC), greenhouse gases or dangerous particles into indoor or outdoor air; (c) the emission of dangerous radiation; (d) the release of dangerous substances into ground water, marine waters, surface waters or soil; (e) the release of dangerous substances into drinking water (f) faulty discharge of waste (g) dampness

8 EU project OSIRYS FOREST BASED COMPOSITES FOR FAÇADES AND INTERIOR PARTITIONS TO IMPROVE INDOOR AIR QUALITY IN NEW BUILDS AND RESTORATION THEME EeB.NMP Safe, energy-efficient and affordable new eco-innovative materials for building envelopes and/or partitions to provide a healthier indoor environment

9 Project objective Development of biocomposites with different functionalities able to meet the strictest requirements of the Building Code with regard to:

10 Goal of the project Materials with low emissions: avoidance of particles, VOC and formaldehyde generation Improve transpirability to avoid mould and microorganisms generation Materials that decontaminate Material Design Product Multilayer facade Light facade (curtain wall, windows) Interior partitions

11 Analysis of IAQ We have developed and tested the methodology for assessment of building materials for indoor use with respect to: Primary emission of Volatile Organic Compounds from the materials using a recognized assessment scheme (based in German AgBB scheme) Formation and emission of secondary compounds products from the reaction between the materials and ozone The rate of deposition of ozone onto the materials (passive removal of ozone from indoor air) Propensity of mold growth on the materials

12 Method for primary emissions Emission test according to the German AgBB scheme AgBB = Committee for Health-related Evaluation of Building Materials Assessment scheme - criteria ISO :2006: Indoor air Part 9: Determination of the emission of volatile organic compounds from building products and furnishing Emission test chamber method substances are evaluated based on LCI (Lowest Concentration of Interest) R i = C i /LCI i R = sum of all R i additivity R < 1 no effects The materials are tested for the emission of VOC and formaldehyde (and other aldehydes): after 3 and 28 days 1 m 3 emission chamber temperature of 23 ± 2 o C relative humidity 50 ± 5 % air exchange rate 0.5 h -1 Material to be accepted or rejected

13 Method for secondary emissions Ozone deposition velocity Ozone reacts on/with the material exposure for ozone - VOC and aldehydes sampled before and after ozonation Material removes ozone passive ozone removal desired properties: low in reaction products high in deposition velocity

14 Method for microbiological resistance Mold test according to a standard: SIS-TS 41 Determination of critical moisture level for mold growth on building materials (Laboratory method) extended with two levels of relative humidity and more often controls/read-outs Mold spores sprayed on the samples Six levels of relative humidity maintained by saturated solutions of inorganic salts: % Constant temperature of 22 o C Test duration of 16 weeks Control at week 1, 2, 3, 4, 6, 8, 10, 12, 14 and 16 Chamber with exposure containers Mold species: Eurotium herbariorum Aspergillus versicolor Penicillium chrysogenum Aureobasidium pullulans Cladosporium sphaerospermum Stachybotrys chartarum Penicillium funiculosum Chaetomium globosum Aspergillus restrictus Penicillium sp.

15 VOC Compound CAS# Day 3 µg/m 3 Fire resistant biocomposite Day 28 µg/m 3 LCI Ri = µg/m 3 Ci/LCIi Cyclohexanone Cyclohexanol Benzylalcohol TVOC n.a VOC Compound CAS# Day 3 µg/m 3 Primary emissions Aldehydes/Carbonyls Compound CAS# Biocomposite profile Day 28 µg/m 3 R < 1 LCI µg/m 3 Ci/LCIi Methyl-methylethylcyclohexane Toluene Styrene Tetradecane Heptylcyclohexane Methyltetradecane Pentadecane Octylcyklohexanon Benzaldehyde Formic acid phenylmethylester Methoxyphenol Benzylalkohol TVOC n.a Day 3 Day 28 µg/m 3 µg/m 3 LCI Ri = µg/m 3 Ci/LCIi Formaldehyde Acetaldehyde Acetone Butanone Isovaleraldehyde R > 1 Aldehydes/Carbonyls Compound CAS# Day 3 Day 28 µg/m 3 µg/m 3 LCI Ri = µg/m 3 Ci/LCIi Formaldehyde Acetaldehyde Acetone Butanon Butyraldehyde Benzaldehyde Isovaleraldehyde TVOC 28 < 1000 µg/m 3 ISO (2012): Indoor air - Part 6: Determination of volatile organic compounds in indoor and test chamber air by active sampling on Tenax TA sorbent, thermal desorption and gas chromatography using MS or MS-FID. ISO (2013): Indoor air - Part 3: Determination of formaldehyde and other carbonyl compounds in indoor air and test chamber air - Active sampling method.

16 Secondary emissions Fire resistant biocomposite 50 2 panels 35 x 35 cm Ozone 700 ppb 50 Biocomposite profile 2 panels 66 x 36 cm Ozone 780 ppb 40 before ozone after ozone 40 before ozone after ozone Concentration in µg/m Concentration in µg/m Formaldehyde Acetaldehyde Aceton Acrolein Propanal Crotonaldehyde 2-Butanon Butanal Benzaldehyd 3-Methypentanal Pentanal 2-Methylbenzaldehyde 4-Methylbenzaldehyde Hexanal Heptanal Octanal Nonanal Decanal Undecanal Dodecanal 0 Formaldehyde Acetaldehyde Aceton Acrolein Propanal Crotonaldehyde 2-Butanon Butanal Benzaldehyd 3-Methypentanal Pentanal 2-Methylbenzaldehyde 4-Methylbenzaldehyde Hexanal Heptanal Octanal Nonanal Decanal Undecanal Dodecanal Increase in concentration of the carbonyl compounds - oxygenated reaction products Concentration in all products below LCI

17 Ozone deposition velocity Fire resistant biocomposite Biocomposite profile 2 panels 35 x 35 cm 2 panels 66 x 36 cm 800 Air Exchange Rate = 0.5 h -1 Decay of ozone concentration Exponential fit 1 st order kinetics with material without material removal by AER 600 Ozone (ppb) Ozone (ppb) with material without material removal by AER time (minutes) time (minutes) without material s -1 with material s -1 modelled for AER s -1 without material s -1 with material s -1 modelled for AER s -1 v d chamber v d material = cm/s = cm/s v d chamber = cm/s v d material = 0.42 cm/s

18 Microbiological resistance RH = 70-85% RH = 90% scale microbial growth Spruce reference Pine reference Fire resistant biocomposite Biocomposite/profile scale microbial growth Spruce reference Pine reference Fire resistant biocomposite Biocomposite/profile number of weeks RH = 95% number of weeks scale microbial growth Spruce reference Pine reference Fire resistant biocomposite Biocomposite/profile number of weeks No growth Grading scale Initial growth, one or a few hyphes or few branches, scattered on the surface, no conidiophores Clearly established but sparse growth scattered on the surface, branched occasionally with a few conidiophores Patchy heavy growth, mycelia often with many well developed conidiophores Heavy growth on more or less the entire surface

19 Conclusions Biocomposites (TP and TS) are suitable materials to be used for building envelopes and contribute possitively to IAQ Do not release particles VOC, formaldehyde and other aldehydes emissions are below LCI Oxygenated product are formed in presence of ozone, but concentration remains safe Contribute to ozone removal through deposition Microbiological resistance up to 85% RH is total. At RH>90% simple additivation during formulation is enough to avoid microbiological growth.

20 Thank you for your attention! OSIRYS Consortium