Emission of Volatile Oganic Compounds from Wood and Wood-Based Materials

Appendix 6: Emissions from Wood and Wood-Based Products - Results in Details

Results in details cover emissions quantified from the 23 kinds of solid wood and wood-based materials and products investigated by chamber testing.

List of Contents

Description of test specimens

List of results in details

Chemical analyses

Sensory determinations

Test Specimens

The tested materials and products cover products of varying complexicity including solid wood, wood-based boards, veneered particleboards, oil-treated solid beech and lacquered veneered particleboards.

The test specimens are briefly described below:

Solid wood

Solid wood is generally sampled by the sawmill after drying in their usual production line and forwarded to the testing laboratory. Upon receipt at the laboratory the test specimens were sampled and sealed in emission free plastic. The materials were stored frozen in order to avoid growth of mould and fungi.

B1 Ash, Danish origin. Planks: 132 x 25 mm
Moisture content approx. 9% according to supplier's information.
Moisture content approx. 11.1% and 8.7% at start and end of chamber testing respectively.

B2 Oak, German origin. Planks: 132 x 27 mm
Moisture content approx. 9% according to supplier's information.
Moisture content approx. 11.3% and 9.3% at start and end of chamber testing respectively.

B3 Beech, Danish origin. Planks: 132 x 25 mmMoisture content approx. 9% according to supplier's information.
Moisture content approx. 13.8% and 9.3% at start and end of chamber testing respectively.

B4 Spruce, south Scandinavian origin. Planks: 135 x 40 mm
Moisture content approx. 9% according to supplier's information.
Moisture content approx. 11.1% and 8.7% at start and end of chamber testing respectively.

A13 Pine, Finnish origin. Heartwood share: approx. 84%
Moisture content approx. 17.0% and 10.4% at start and end of chamber testing respectively.

A14 Pine, Finnish origin. Sapwood share: approx. 96%
Moisture content approx. 14.0% and 9.9% at start and end of chamber testing respectively.

A15 Pine, Swedish origin. Heartwood share: approx. 67%
Moisture content approx. 15.9% and 9.6% at start and end of chamber testing respectively.

A16 Pine, Swedish origin. Sapwood share: approx. 98%
Moisture content approx. 17.5% and 10.1% at start and end of chamber testing respectively.

Wood-based Panels
Wood-based panels are sampled by the supplier. Upon receipt at the laboratory the test specimens were sampled and sealed in emission free plastic.

C6 Particleboard of pine and spruce, MelamineUreaPhenolFormaldehyde
(MUPF)-glue
Panels: 2000 x 1000 x 16 mm
Production week: 50, 1995. Receipt at laboratory week: 51, 1995.
Moisture content approx. 7.6% during chamber testing.

C7 Particleboard of pine and spruce, UreaFormaldehyde (UF)-glue
Panels: 2000 x 1000 x 16 mm
Production week: 50, 1995. Receipt at laboratory week: 51, 1995.
Moisture content approx. 6.7% and 7.4% at start and end of chamber testing respectively.

D8 Particleboard of pine and spruce, PolyUrethane (PU)-glue
Panels: 2700 x 1000 x 16 mm
Production week: 51, 1995. Receipt at laboratory week: 1, 1996.
Moisture content approx. 6.1% and 7.0% at start and end of chamber testing respectively.

D9 Birch Plywood, Phenol-glue
Panels: 2000 x 1000 x 15 mm
Production week: 4, 1996. Receipt at laboratory week: 5, 1996.
Moisture content approx. 9.3% and 8.7% at start and end of chamber testing respectively.

D10 Medium Density Fiberboard (MDF) of conifer, UreaFormaldehyde (UF)-glue
Panels: 500 x 500 x 15 mm
Production week: 4, 1996. Receipt at laboratory week: 8, 1996.
Moisture content approx. 5.1% and 5.3% at start and end of chamber testing respectively.

D17 Oriented Strand Board (OSB) of conifer, Phenol-glue
Panels: 2440 x 1220 x 15 mm
Production week: 8, 1996. Receipt at laboratory week: 25, 1996.
Moisture content approx. 6.1% during chamber testing.
Veneered particleboards
Particleboard UF-glue (C7) was used as basis for gluing on a 0.6 mm beech-veneer.

C11 Beech-veneered particleboard, PolyVinylAcetate (PVA)-glue for gluing-on veneer
Panels: 500 x 500 x 16 mm
Moisture content approx. 8.1% and 7.8% at start and end of chamber
testing respectively.

C12 Beech-veneered particleboard, UreaFormaldehyde (UF)-glue for gluing-on veneer
Panels: 500 x 500 x 16 mm
Moisture content approx. 6.4% and 7.4% at start and end of chamber
testing respectively.
Oil-treated solid beech
Solid beech (B3) was used as basis for the oil-treatment.

F18 Urethane alkyd and linseed-oil based oil for floors on planed beech planks.
Application of oil according to supplier's information. Applied amount
approx. 80 g/m².
Moisture content approx. 10.0% at the end of chamber testing.

F19 Natural resin and linseed-oil based oil for floors on planed beech planks.
Application of oil according to suppliers information. Applied a
ount approx. 84 g/m².
Moisture content approx. 10.4% at the end of chamber testing.

Lacquered veneered particleboards
Beech-veneered particleboard glued with ureaformaldehyde-glue (C12) was used as basis for the surface coatings. The application and drying of lacquer were made by the paint and varnish manufacturer using industrial equipment and procedures.

E20 Nitrocellulose lacquer on beech-veneered particleboard.
Spray application of 1 ground- and 1 top-coat of nitrocellulose lacquer was carried out 4 weeks before start of chamber testing. Applied amount in total approx. 200 g/m².
Moisture content approx. 7.9% at the end of chamber testing.

E21 UV-curing lacquer on beech-veneered particleboard.
Roll application of 2 ground- and 1 top-coat of UV-curing lacquer was carried out 4 weeks before start of chamber testing. Applied amount in total approx. 38 g/m².
Moisture content approx. 7.9% at the end of chamber testing.

E22 Acid-curing lacquer on beech-veneered particleboard.
Spray application of 1 ground- and 1 top-coat of acid-curing lacquer was
carried out 4 weeks before start of chamber testing. Applied amount in total
approx. 200 g/m².
Moisture content approx. 7.7% at the end of chamber testing.

E23 Water-based acrylic lacquer on beech-veneered particleboard.
Spray application of 1 ground- and 1 top-coat of acrylic lacquer was
carried out 4 weeks before start of chamber testing. Applied amount in total
approx. 200 g/m².
Moisture content approx. 8.0% at the end of chamber testing.

F24 Polyurethane lacquer on beech-veneered particleboard.
Spray application of 1 ground- and 1 top-coat of polyurethane lacquer was carried out 4 weeks before start of chamber testing. Applied amount in total approx. 200 g/m².

Moisture content approx. 7.7% at the end of chamber testing.

Results in Details - Chemical Analyses

The lists of results in details refer to the following data:

Sample identification and description

The brief sample identifications and description refer to the test specimens described on the first pages of this Appendix.

Testing procedure

The chamber testing was carried out according to the test method given in Appendix 3.

The test chambers used were made of stainless steel and had a volume of 225 litres. The tests were carried out at the standard test conditions of 45±5% relative humidity, 23±0.5EC and at a loading factor (L) and air exchange rate (n) ratio: n/L = 1. Refer to Appendix 3 for additional information.

The qualitative screening has been carried out by headspace analysis. The material to be examined was placed in a diffusion tight bag with a relatively low amount of clean air and heated to 120ºC for 1 hour. An air sample of 1 ml has been sampled with a gas tight syringe and analysed by head space capillary column gas chromatography combined with mass spectrometric detection (GC-MS).

Experimental conditions:

GC:

Capillary column: 35 m x 0.32 mm x 0.25 µm CP-Sil 8CB (5% phenyl methylsilicone)

Injection method: 1 ml split at 250ºC, split relation 1:5

Temperature programme: 0°C (1.0 min.), to 280ºC with 15EC/min.

Carrier gas: Helium, inlet pressure 5 psi

MS

Interface: 280ºC

Detection: Full scan m/z 25-400

The quantitative analyses have been carried out by collection of gases and vapours on adsorption tubes of charcoal and tenax and extracted by solvent desorption with carbon disulphide and dietyether respectively with isotop marked internal standard. The eluates were thereafter analyzed by GC-MS.

Experimental Conditions:

GC:

Capillary column: 50 m x 0.32 mm x 0.25 µm CP-Sil 8CB

(5% phenyl methyl silicone)

MS:

Interface: 280ºC

Detection: Full scan m/z 25-350

Tenax Tubes:

Injection: 2 Fl splitless at 250ºC

Temperature 20ºC (3.0 min.), to 70ºC with 10ºC/min, to

programme: 300ºC with 20ºC/min, kept 5.0 min.

Carrier gas: Helium, constant flow 1.2 mil/min (3.1 psi at 20°C)

Injection: 2 Fl splitless at 250°C

Temperature 20ºC (3.0 min.), to 70ºC with 10ºC/min, to

programme: 300ºC with 20ºC/min, kept 5.0 min.

Carrier gas: Helium, inlet pressure 5 psi

Chemical identity of quantified substances

The chemical identity is given by name of chemical substance, type of chemical substance and CAS-number.

Emission results in detail

All individual chemical substances quantified are included in the lists.

The measured "Emission rate" and the "Calculated Standard Room Concentration" are given to each of the 3 measurement times: 3-4 days, 9-11 days and 27-28 days respectively.

The standard room concentration was calculated for the area-interval 0.1 m² till 38 m² in a standard room with a volume of 17.4 m³, covering a material-load interval from 0.006 to 2.2 m²/m³, to obtain a basis for toxicological considerations. It should, however, be noted that most of the tested materials and products are not commonly used over this large interval. Common material-load for untreated solid wood of ash, beech and oak; untreated wood-based panels; uncoated veneered wood-based panels and oil-treated solid wood for floors are approx. 0.4 m²/m³ or less.

A load of 2.2 m²/m³ can be seen for materials covering all surfaces of a room e.g. untreated solid wood of pine and spruce and for lacquered surfaces.

The principles for conversion of concentrations from test chamber to standard room are gone through in Appendix 4-5, page 5. This results in:

and

At chamber conditions with a material load L_k = 1 m²/m³ and an air exchange rate n_k = 1 h^-1 the test chamber concentration is equal to the emission rates in the test chamber: C_ki = R_ki ±

The concentration in the standard room can be calculated from:

For A_s = 0.1 m² in V_s = 17.42 m³ standard room at an air exchange rate of

n_s = 0.5 h^-1:

For A_s = 38 m² in V_s = 17.42 m³ standard room at an air exchange rate of

n_s = 0.5 h^-1:

Method of analyses:

SD-GCMS = Gas Chromatography with Mass Spectrometric detection.

SD indicates solvent desorption. Tenax and charcoal respectively indicate the collection media used.

DNPH-HPLC = High Pressure Liquid Chromatography for aldehydes by use of DiNitroPhenylHydrazine reagent tubes and acetonitrile extraction.

Acetylacetone-method = A photometric method for determination of especially formaldehyde based on Hartzsch reaction in which formaldehyde reacts with ammonium ions and acetylacetone. Determination by the acetylacetone-method is in accordance with the analytic procedure given in e.g. prEN 717-1:"Wood-based panels. Determination of formaldehyde release. Part.1: Formaldehyde emission by the chamber method".

LCI-values

Lowest Concentration of Interest in the indoor air is estimated for each emitted chemical substance. The background for the LCI-values is given in Chapter 4 and 5 on principles for evaluation of the health and sensory effects of VOC emission from wood and wood-based products and in Appendix 7 on evalua-tion of single substances.

Odour threshold

Odour threshold refers to odour threshold values given in the air quality databank, VOCBASE, 1996.

The results of the chemical analyses, expressed in emission rates [µg/m²h] and calculated standard room concentrations of the individual chemical substances emitted, are given in the diagrams on the following pages.

The test results of the sensory determinations are given on the last pages of this Appendix.

Results in Details. Sensory Determinations

Directory sensory testing of odour perception has been carried out for spruce, beech veneered particleboard with by polyvinyl acetate glue and UV-curing lacquer on beech veneered particleboard by chamber testing (Danish Society of Indoor Climate. "Standard Test Method for Determination of Emission from Building Products" 1994) in Climpaq-chamber with odour funnel diffuser allowing sensory evaluation by sniffing, see Appendix 4, part on "Evaluation of sensory determination".

The determination was carried out to the time-value 1 day and with approx. 0.9 m² material load corresponding to approx. 0.12 m²/ m; converted to the standard room of 17.4 m³ (Danish Standard, DS/INF 90, 1994).

Sensory determination - Individual panel evaluation

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Results of sensory determination expressed as median and average.