Formaldehyde Emissions: Hardwood Plywood and ... - ACS Publications

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Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on October 27, 2015 | http://pubs.acs.org Publication Date: August 8, 1986 | doi: 10.1021/bk-1986-0316.ch002

Formaldehyde Emissions: Hardwood Plywood and Certain Wood-Based Panel Products William J. Groah Hardwood Plywood Manufacturers Association, 1825 Michael Faraday Drive, Reston, VA 22090

Hardwood plywood products are decorative in nature and are designed for interior use. Over 95% of all hardwood plywood is made with urea-formaldehyde adhesives. Responding to concerns about formaldehyde and certain wood products, test methods for measuring surface emissions were developed in the early 1980's. Emissions from most hardwood plywood and particleboard products have decreased 65% to 95% in recent years primarily by use of low emitting UF adhesives and/or scavengers. Good correlation has been demonstrated between product test methods and indoor levels of formaldehyde in experimental manufactured homes. Decorative surface finishes can act to either increase or decrease surface emissions, depending on the nature of the finish and the substrate.

L i n e s o f d e m a r c a t i o n between hardwood plywood, softwood plywood a n d c e r t a i n o t h e r wood b a s e d p a n e l p r o d u c t s h a v e become l e s s d i s t i n c t i n r e c e n t y e a r s . One o f t h e m o s t i m p o r t a n t d i s t i n c t i o n s i n respect t o formaldehyde emission p o t e n t i a l i s that softwood plywood i s t y p i c a l l y bonded w i t h p h e n o l - f o r m a l d e h y d e w h i l e hardwood plywood i s t y p i c a l l y bonded w i t h u r e a - f o r m a l d e h y d e . P h e n o l - f o r m a l d e h y d e a d h e s i v e s a r e more s t a b l e a n d have l e s s t e n d e n c y t o e m i t f o r m a l d e h y d e t h a n do u r e a - f o r m a l d e h y d e a d h e s i v e s . Some i m p o r t a n t f e a t u r e s o f h a r d w o o d 1.

2. 3. 4.

plywood:

The f a c e v e n e e r i s u s e d t o d e s c r i b e t h e p r o d u c t . Oak p l y w o o d , f o r example, w i l l have oak f a c e v e n e e r ; t h e i n n e r l a y e r s and b a c k v e n e e r w i l l l i k e l y b e o f some o t h e r p r o d u c t o r s p e c i e s . Most hardwood plywood p r o d u c t s a r e d e c o r a t i v e i n n a t u r e . Most hardwood plywoods a r e d e s i g n e d f o r i n t e r i o r a p p l i c a t i o n . Face veneers t y p i c a l l y a r e h i g h q u a l i t y . F o r many f a c e 0097-6156/86/0316-0017S06.00/0 © 1986 A m e r i c a n C h e m i c a l Society

In Formaldehyde Release from Wood Products; Meyer, B., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

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5.


6.

FORMALDEHYDE

RELEASE FROM WOOD

PRODUCTS

s p e c i e s t h e c o s t o f l o g s i s h i g h and f a c e s a r e s l i c e d t h i n , r a n g i n g f r o m a b o u t 1/20" t o 1 / 1 0 0 " i n t h i c k n e s s . B e c a u s e f a c e v e n e e r s a r e d e c o r a t i v e and t h i n , a c o l o r l e s s g l u e l i n e i s d e s i r e d t o p r e v e n t d i s c o l o r a t i o n on t h e f a c e . Urea-formaldehyde adhesives are predominate i n the manufacture of hardwood p l y w o o d . W e l l o v e r 95% o f a l l hardwood plywood c o n s u m e d i n t h e U.S. i s made f r o m UF a d h e s i v e s .

A p p a r e n t U.S. c o n s u m p t i o n o f h a r d w o o d p l y w o o d i n 1983 was 4.3 b i l l i o n s q u a r e f e e t s u r f a c e m e a s u r e h a v i n g a v a l u e o f a b o u t 1.1 b i l l i o n d o l l a r s . About 2 / 3 ' r d s , on a s u r f a c e measure b a s i s , was i m p o r t e d , I n d o n e s i a b e i n g t h e p r i m a r y e x p o r t i n g c o u n t r y , w i t h K o r e a , T a i w a n , P h i l i p p i n e s and M a l a y s i a a l s o b e i n g i m p o r t a n t factors. Formaldehyde e m i s s i o n and/or formaldehyde space l e v e l p o t e n t i a l c a n be r e l a t e d t o b o t h c o n s t r u c t i o n t y p e a n d p r o d u c t e n d use. W h i l e t h e A m e r i c a n N a t i o n a l S t a n d a r d f o r Hardwood and D e c o r a t i v e P l y w o o d (1_) r e f e r e n c e s e i g h t d i f f e r e n t t y p e s o f c o n s t r u c t i o n , t h r e e a r e most i m p o r t a n t i n the c o n t e x t o f f o r m a l d e hyde: V e n e e r c o r e - 3, Particleboard

5,

7,

9 p l y and

greater

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Medium D e n s i t y F i b e r b o a r d c o r e - 3 p l y B o t h p a r t i c l e b o a r d a n d MDF c o r e a r e c h a r a c t e r i s t i c a l l y 3 - p l y a n d h a v e two p o t e n t i a l s o u r c e s o f f o r m a l d e h y d e : the adhesive used t o a d h e r e t h e hardwood f a c e and b a c k t o t h e c o r e , and t h e a d h e s i v e b i n d e r used i n the manufacture of the p a r t i c l e b o a r d or MDF. Hardwood plywood m a n u f a c t u r e r s a r e t y p i c a l l y n o t v e r t i c a l l y i n t e g r a t e d a n d do n o t p r o d u c e c o m p o s i t i o n b o a r d c o r e s , t h u s a r e d e p e n d e n t on o t h e r c o m p a n i e s o r p l a n t s f o r p a r t i c l e b o a r d and MDF. The s i n g l e l a r g e s t e n d u s e f o r h a r d w o o d p l y w o o d i s i n t e r i o r w a l l p a n e l s , g e n e r a l l y 3 - p l y a n d 1/4" a n d t h i n n e r , a n d f r e q u e n t l y machined w i t h d e c o r a t i v e v-grooves. F u r n i t u r e , c a b i n e t s , door s k i n s and a number o f s p e c i a l t i e s c o m p l e t e an a r r a y o f end u s e products. Many o f t h e n o n w a l l p a n e l p r o d u c t s c a n be c h a r a c t e r i z e d as b e i n g i n d u s t r i a l p a n e l s and a r e o f 5 o r more p l y v e n e e r c o r e , 3 - p l y p a r t i c l e b o a r d c o r e , o r 3 - p l y medium d e n s i t y f i b e r b o a r d (MDF) c o r e c o n s t r u c t i o n . B r o a d end u s e p a t t e r n s i n d i c a t e t h a t i n t e r i o r w a l l p a n e l s r e p r e s e n t a p p r o x i m a t e l y 55% o f t o t a l hardwood plywood consumption. F u r n i t u r e , c a b i n e t s , and f i x t u r e s r e p r e s e n t a b o u t 3 0 % , and d o o r s k i n s and s p e c i a l t y p r o d u c t s a b o u t 15% (2.). P o t e n t i a l s o u r c e s o f f o r m a l d e h y d e i n two o f t h e m o r e t y p i c a l h a r d w o o d p l y w o o d c o n s t r u c t i o n s a r e d i s p l a y e d i n F i g u r e 1. Formaldehyde Issue

Benchmarks

The p o t e n t i a l f o r e l e v a t e d a m b i e n t f o r m a l d e h y d e l e v e l s became apparent i n manufactured housing d u r i n g the l a t e 1970*s. Federal standards governing the c o n s t r u c t i o n of manufactured or mobile homes f i r s t b e c a m e e f f e c t i v e i n 1 9 7 6 , a p e r i o d w h i c h c o i n c i d e d w i t h t h e d r a m a t i c i n c r e a s e i n c o s t o f e n e r g y and t h e t i g h t e n i n g


GROAH

Plywood

and Wood-Based

Panel

Products


3-PLY WALL PANEL GLUE LINE

GROOVES MAY EXPOSE GLUE LINES

3-PLY INDUSTRIAL PANEL GLUE LINE BETWEEN

ADHESIVE BINDER FOR BONDING PARTICLES TOGETHER

F i g u r e 1. P o t e n t i a l s o u r c e s o f f o r m a l d e h y d e hardwood plywood c o n s t r u c t i o n s .

i n two t y p i c a l



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FORMALDEHYDE RELEASE FROM WOOD

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o f homes o f a l l t y p e s . I n t h e l a t e 1 9 7 0 ' s , t h e d o m e s t i c h a r d w o o d p l y w o o d i n d u s t r y became s i g n i f i c a n t l y i n v o l v e d i n r e s p o n d i n g t o c o n c e r n s about hardwood plywood as a p o t e n t i a l s o u r c e o f f o r m a l d e h y d e e m i s s i o n s . The p r i m a r y i n d u s t r y f o c u s h a s b e e n o n w a l l p a n e l use i n m a n u f a c t u r e d h o u s i n g because o f low a i r exchange r a t e s c o u p l e d w i t h h i g h p r o d u c t usage o r l o a d i n g . A f e w y e a r s ago i t was n o t uncommon f o r d e c o r a t i v e w a l l p a n e l i n g t o be u s e d o n a l m o s t a l l i n t e r i o r w a l l s i n m o b i l e h o m e s . The u s e o f wood w a l l p a n e l s i n m a n u f a c t u r e d homes h a s d e c l i n e d i n r e c e n t y e a r s b u t is s t i l l significant. One o f t h e f i r s t m a j o r e f f o r t s was t o i n v e s t i g a t e how f o r m a l d e h y d e e m i s s i o n s f r o m p r o d u c t s c o u l d be d e t e r m i n e d . This e v e n t u a l l y r e s u l t e d i n two i n d u s t r y d e v e l o p e d t e s t m e t h o d s : the two h o u r d e s i c c a t o r t e s t d e s i g n a t e d a s FTM 1, a n d t h e l a r g e l a b o r a t o r y c h a m b e r t e s t d e s i g n a t e d a s FTM 2 ( 3 . , 4 ) . Concomitant w i t h t h e a s s e s s m e n t o f a n a l y t i c a l t e c h n i q u e s and t h e development o f t e s t m e t h o d s was a n e f f o r t t o d e t e r m i n e t h e p o t e n t i a l f o r r e d u c i n g formaldehyde e m i s s i o n s from hardwood plywood. A product e m i s s i o n s u r v e y o f h a r d w o o d p l y w o o d p r o d u c t s was made a b o u t 1980 to determine the then current s t a t e - o f - t h e - a r t . In o b t a i n i n g s a m p l e s f o r t h e t h e s u r v e y , p l y w o o d was c h a r a c t e r i z e d a s s t a n d a r d , low__emitting and odor f r e e . T h i s t e r m i n o l o g y was s e l e c t e d t o be s i m i l a r t o t h a t used i n J a p a n and p e r h a p s w e l l u n d e r s t o o d by o t h e r countries i n the A s i a n region. P r o d u c t s were o b t a i n e d from v a r i o u s companies i n A s i a and N o r t h A m e r i c a . The r e s u l t s o f t h e s u r v e y a p p e a r e d t o d e m o n s t r a t e t h a t e m i s s i o n s c o u l d be r e d u c e d b y 65% t o 95%. Reducing Formaldehyde

Emissions

T e c h n i c a l c o n s i d e r a t i o n s , r e s i n c o s t , and r e s i n a v a i l a b i l i t y have a n d a r e d i c t a t i n g l o w e m i t t i n g UF s y s t e m s a s t h e p r i m a r y s u b s t i t u t e f o r s t a n d a r d UF a d h e s i v e s . R e l a t i v e l y s m a l l q u a n t i t i e s o f h a r d w o o d p l y w o o d h a v e b e e n made w i t h p o l y v i n y l a c e t a t e a n d p h e n o l f o r m a l d e h y d e , t h e two m o s t l i k e l y s u b s t i t u t e s . C o s t i s a p r i m a r y d i s a d v a n t a g e o f PVA t y p e s a n d c e r t a i n u s e p a r a m e t e r s a n d the dark c o l o r o f p h e n o l l i m i t t h a t a d h e s i v e t o c e r t a i n hardwood plywood f a c t o r i e s and f o r c e r t a i n a p p l i c a t i o n s . Reduction i n the emission c h a r a c t e r i s t i c s of u n f i n i s h e d hardwood p l y w o o d i s c u r r e n t l y b e i n g a c h i e v e d p r i m a r i l y by t h e use of low formaldehyde t o u r e a m o l a r r a t i o f o r m u l a t i o n s . For the m a n u f a c t u r e o f hardwood plywood and p a r t i c l e b o a r d , f o r m a l d e h y d e t o u r e a m o l a r r a t i o s h a v e b e e n r e d u c e d t o a r a n g e o f 1.15/1 t o 1 . 3 / 1 . A n i m p o r t a n t c a v e a t ; l o w F/U r a t i o s p e r h a p s s h o u l d be c o n s i d e r e d a proxy f o r the p o t e n t i a l t o reduce e m i s s i o n s through improved u r e a f o r m a l d e h y d e a d h e s i v e t e c h n o l o g y r a t h e r t h a n t h e e x c l u s i v e means f o r improvement. R e d u c i n g t h e F/U r a t i o i s n o t a l w a y s t h e m o s t e f f e c t i v e way o f r e d u c i n g e m i s s i o n s i n c o n s i d e r a t i o n o f t h e v a r i e t y o f hardwood plywood c o n s t r u c t i o n s , p r o d u c t s , and t h i c k nesses . S u r f a c e a p p l i e d p o s t t r e a t m e n t s a r e a l s o commonly b e i n g u s e d . M y e r s (5.) h a s d o c u m e n t e d t h e e f f e c t i v e n e s s o f a l a b o r a t o r y a p p l i e d ammonia t r e a t m e n t a n d a l s o a u r e a c o n t a i n i n g c o a t i n g t o h a r d w o o d plywood. I n p r a c t i c e most c o m m e r c i a l t r e a t m e n t s a r e a p p l i e d by r o l l e r c o a t e r s and t h e e f f e c t i v e n e s s o f t h e t r e a t m e n t depends n o t


2.

GROAH

Plywood

and

Wood-Based

Panel

21

Products

o n l y on t h e t r e a t m e n t m a t e r i a l b u t a l s o t h e a p p l i c a t i o n r a t e and the nature of the product being t r e a t e d . Exact f o r m u l a t i o n s are t y p i c a l l y p r o p r i e t a r y but most t r e a t m e n t s a r e b e l i e v e d t o c o n t a i n some ammonia o r u r e a compound a n d a r e a p p l i e d a t r a t e s t h a t a c h i e v e a 30% t o 85% r e d u c t i o n i n f o r m a l d e h y d e e m i s s i o n s . Some m a n u f a c t u r e r s u s e b o t h l o w e m i t t i n g UF a d h e s i v e s y s t e m s a n d p o s t treatments.


Two

Product

R e l a t e d F a c t o r s T h a t Can

Effect

Emissions

S u r f a c e f i n i s h e s c a n be a n i m p o r t a n t f a c t o r i n e i t h e r i n c r e a s i n g or decreasing emissions. T h i s became a p p a r e n t as f o r m a l d e h y d e e m i s s i o n s d e c r e a s e d a s a r e s u l t o f c h a n g e s i n UF a d h e s i v e s . Wall p a n e l p r o d u c t s c a n be s e g m e n t e d b y t h e t y p e o f d e c o r a t i v e s u r f a c e f i n i s h i n order of commercial importance. Paper Overlays - (40% of w a l l panel consumption) are 1 t o m i l p r i n t e d p a p e r f i l m s a d h e r e d t o l a u a n p l y w o o d w i t h PVA other adhesive. Paper f i l m s are a v a i l a b l e i n pre-topcoat non p r e - t o p c o a t v a r i e t i e s .

2 or or

P r i n t e d - (35%) s u r f a c e s a r e d e c o r a t i v e p a t t e r n or s i m u l a t e d wood g r a i n e f f e c t s c r e a t e d b y t h e a p p l i c a t i o n o f l i q u i d a p p l i e d b a s e c o a t s , i n k s and p r o t e c t i v e t o p c o a t s t o l a u a n o r o t h e r t r o p i c a l hardwoods. N a t u r a l Hardwoods - (18%) d e s c r i b e e s s e n t i a l l y t r a n s p a r e n t f i n i s h s y s t e m s on s p e c i e s s u c h as w a l n u t , oak, b i r c h , p e c a n , cherry, etc. V i n y l Overlay - (7%) are 2 m i l or t h i c k e r p r i n t e d v i n y l a d h e r e d t o l a u a n p l y w o o d w i t h PVA o r o t h e r a d h e s i v e s .

films

The d o m e s t i c h a r d w o o d p l y w o o d i n d u s t r y h a s b e e n t r e n d i n g t o w a r d s t h e u s e o f w a t e r b a s e d t o p c o a t s f o r some p a p e r o v e r l a y , p r i n t e d , and n a t u r a l hardwood p a n e l i n g p r o d u c t s t o r e d u c e v o l a t i l e o r g a n i c compound e m i s s i o n s . To a c h i e v e d e s i r e d s u r f a c e p r o d u c t p r o p e r t i e s f o r m a l d e h y d e i s o f t e n a component o f the t o p c o a t . There have been e f f o r t s t o r e d u c e t h e amount o f e m i t t a b l e f o r m a l dehyde i n t o p c o a t s o r t o r e f o r m u l a t e t o e l i m i n a t e f o r m a l d e h y d e as a component. F i n i s h e s i n some c a s e s a l s o a p p e a r t o r e d u c e e m i s s i o n s f r o m w a l l paneling products. The e f f e c t i v e n e s s o f a v i n y l f i l m o v e r l a y was e v a l u a t e d u s i n g h i g h e m i t t i n g h a r d w o o d p l y w o o d w a l l p a n e l s (.6). Formaldehyde emissions from the v i n y l s u r f a c e of plywood were compared w i t h the b a c k or unexposed plywood s u r f a c e u s i n g b o t h t h e l a r g e c h a m b e r a n d t h e two h o u r d e s i c c a t o r . T h i s comp a r i s o n i n d i c a t e d t h a t a 2 - m i l v i n y l was a b o u t 9 0 % e f f e c t i v e i n reducing emissions. The n u m b e r o f V - g r o o v e s c a n be a f a c t o r , p a r t i c u l a r l y w h e n o n l y p o s t s u r f a c e t r e a t m e n t s a r e u s e d p r i o r t o p a n e l g r o o v i n g on r e l a t i v e l y high emitting panels. Matched specimens were c a r e f u l l y s e l e c t e d f o r d e s i c c a t o r t e s t i n g t o compare t h e e f f e c t o f number o f g r o o v e s f r o m z e r o t o 16 ( o n e g r o o v e f o r e a c h d e s i c c a t o r s a m p l e s u r f a c e ) from a group of p a n e l s where the improvement i n e m i s s i o n


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c h a r a c t e r i s t i c s was a c h i e v e d p r i m a r i l y by a p o s t s u r f a c e t r e a t ment. A t y p i c a l v - g r o o v e d 4 x 8 w a l l p a n e l has f i v e t o seven grooves which t r a n s l a t e d t o 4 t o 6 grooves i n t h i s study. The d a t a p l o t o f F i g u r e 2 s u g g e s t s t h a t a 30% t o 40% i n c r e a s e i n e m i s s i o n r a t e c o u l d t h e o r e t i c a l l y r e s u l t when g r o o v e s a r e c u t f o l l o w i n g p o s t t r e a t m e n t s o f p a n e l s made w i t h s t a n d a r d UF adhesives. 1


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f

Regulations

P a r t i c l e b o a r d d e c k i n g and hardwood plywood w a l l p a n e l s c a n r e p r e s e n t 80% t o 90% o f t h e t o t a l e x p o s e d s u r f a c e o f f o r m a l d e h y d e c o n t a i n i n g w o o d b a s e d p r o d u c t s i n new m o b i l e h o m e s . Kitchen c a b i n e t s , v a n i t i e s , s h e l v i n g and other b u i l t - i n s a r e p r i m a r i l y made f r o m i n d u s t r i a l p a r t i c l e b o a r d , MDF o r h a r d w o o d p l y w o o d panels. On F e b r u a r y 1 1 , 1985, a r u l e e s t a b l i s h i n g p r o d u c t s t a n d a r d s f o r hardwood plywood and p a r t i c l e b o a r d used i n m a n u f a c t u r e d h o u s i n g b e c a m e e f f e c t i v e . T h e U.S. D e p a r t m e n t o f H o u s i n g a n d U r b a n D e v e l o p m e n t h a s d e s i g n a t e d a chamber l o a d i n g r a t e o f 0.29 s q f t / c u f t a n d c h a m b e r l e v e l o f 0 . 2 ppm f o r h a r d w o o d p l y w o o d , a n d a 0.13 s q f t / c u f t l o a d i n g r a t e , a n d 0 . 3 ppm l e v e l f o r p a r t i c l e board. I n d u s t r i a l Panels, that i s panels that a r e composite i n n a t u r e and a r e used f o r a p p l i c a t i o n s o t h e r t h a n w a l l p a n e l i n g , a l s o h a v e b e e n d e f i n e d b y HUD i n J a n u a r y 1985 t o b e t e s t e d a t a l o a d i n g r a t e o f 0 . 1 3 s q f t / c u f t t o c o n f o r m t o a 0 . 3 ppm c h a m b e r level. HUD m a n d a t e s t h e l a r g e c h a m b e r a s t h e p r i m a r y t e s t m e t h o d t o be u s e d f o r i n i t i a l p r o d u c t c o m p l i a n c e a n d t o be c o n d u c t e d t h e r e a f t e r a t a f r e q u e n c y o f once a q u a r t e r . I n - p l a n t q u a l i t y c o n t r o l and r o u t i n e acceptance t e s t i n g by p r o p e r t y v e r i f i c a t i o n o r g a n i z a t i o n s such a s t h e Hardwood Plywood M a n u f a c t u r e r s A s s o c i a t i o n and t h e N a t i o n a l P a r t i c l e b o a r d A s s o c i a t i o n r e q u i r e a method more e f f i c i e n t t h a n t h e chamber f o r r o u t i n e l y monitoring trends i n emission c h a r a c t e r i s t i c s of products. The r e l a t i o n s h i p b e t w e e n chamber a n d t h e s m a l l s c a l e d e s i c c a t o r t e s t o b s e r v a t i o n s i s i l l u s t r a t e d b y a s e r i e s o f 76 t e s t s a c c o m p l i s h e d d u r i n g t h e p a s t y e a r on hardwood plywood w a l l p a n e l p r o d u c t s a t a chamber l o a d i n g r a t e o f 0.29 s q f t p e r c u f t : Y = 0 . 6 2 X + 0.005 Where:

Y = The chamber v a l u e X = The a v e r a g e d e s i c c a t o r v a l u e i n t h e chamber

[1]

of a l l panels

placed

NOTE: T h e e q u a t i o n a b o v e i s g e n e r i c i n n a t u r e a n d s h o u l d n o t n e c e s s a r i l y be u s e d t o d e s c r i b e t h e s m a l l and l a r g e s c a l e t e s t r e l a t i o n s h i p f o r a l l w a l l panel products. The HUD p r o d u c t s t a n d a r d s a r e t i e d t o t h e o b j e c t i v e o f p r o v i d i n g a 0 . 4 ppm a m b i e n t t a r g e t l e v e l i n new m a n u f a c t u r e d homes. The h y p o t h e s i s t h a t p r o d u c t e m i s s i o n s t a n d a r d s c a n be r e l a t e d t o a m b i e n t f o r m a l d e h y d e l e v e l s w a s t e s t e d i n a HUD s p o n s o r e d p r o j e c t (7.) t h a t i n v o l v e d c o n s t r u c t i n g four experimental m o b i l e homes a n d c o m p a r i n g home o b s e r v e d f o r m a l d e h y d e l e v e l s w i t h



F i g u r e 2. Relationship and number o f V - g r o o v e s

between d e s i c c a t o r formaldehyde i n d e s i c c a t o r samples.

values


FORMALDEHYDE RELEASE FROM WOOD PRODUCTS

24

product emissions in laboratory tests including the large chamber. This experiment demonstrated that home levels could be related reasonably well to chamber levels when plywood paneling and particleboard decking were tested together at manufactured home loading rates. Moreover, it was demonstrated that chamber levels of paneling and decking tested together (in combination) relates to values obtained by the addition of the chamber values for paneling and for decking when tested individually. Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on October 27, 2015 | http://pubs.acs.org Publication Date: August 8, 1986 | doi: 10.1021/bk-1986-0316.ch002

Y = 0.81X - 0.09

[2]

Where: Y is the chamber value for decking and paneling tested in combination. X is the decking value plus the paneling value when the products are tested separately. Concluding Statements While the initial concern for formaldehyde emissions in the hardwood plywood industry was in the wall paneling sector there is a strong and decided movement by many manufacturers to apply new low emitting adhesive technology to other hardwood plywood products. Low emitting UF products are nearing the emission characteristics of certain other resin systems assumed to be likely substitutes. The HUD rule has had an effect far beyond the products designed for manufactured housing. Some companies that make wall panels either do not or may not know where the product will be used. Many companies have elected to use low emitting products that meet HUD product standard requirements even if they know the product will not be used in manufactured homes. It would appear that the wall paneling industry, on average, has probably been able to achieve a 70% to 95% reduction in formaldehyde emissions and s t i l l maintain the use of urea-formaldehyde adhesives. Literature Cited 1. 2.

3.

4.

American National Standards Institute. American National Standard for Hardwood and Decorative Plywood, ANSI/HPMA HP 1983. Hardwood Plywood Manufacturers Association, Comments before the Environmental Protection Agency, regulatory investigation of formaldehyde exposures determined to be within section 4(f) of the toxic substances control act, 1984. National Particleboard Association, Hardwood Plywood Manufacturers Association, Formaldehyde Institute. October 10, 1983. Small scale test method for determining formaldehyde emissions from wood products, two-hour desiccator test, FTM 1, Reston, VA. National Particleboard Association, Hardwood Plywood Manufacturers Association, October 10, 1983. Large scale test method for determining formaldehyde emissions from wood products, large chamber method, FTM 2, Reston, VA.



2. GROAH

Plywood and Wood-Based Panel Products

5. Myers, G. E., Formaldehyde dynamic air contamination by hardwood plywood: effects of several variables and board treatments. Forest Products Journal. 1982; 32(4):20-25. 6. Groah, W., G. Gramp, M. Trant, 1984. Effect of a decorative vinyl overlay on formaldehyde emissions. Forest Products Journal. 1984; 34(4):27-29. 7. Singh, J., R. Walcott, C. St. Pierre, T. Ferrel, S. Garrison, G. Gramp, W. Groah. "Evaluation of the relationship between formaldehyde emission from particleboard mobile home decking and hardwood plywood wall paneling as determined by product test methods and formaldehyde levels in experimental mobile homes." U.S. Dept. of Housing and Urban Development, 1982. RECEIVED January 14, 1986


Formaldehyde Emissions: Hardwood Plywood and ... - ACS Publications

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