Ethylene Dibromide: Regulatory Background

Much attention has recently been focused on the chemical ethylene dibromide (EDB). This chemical has been widely used in leaded gasoline, and has also been used to treat grains, citrus and other crops. It has been found in foods and in groundwater. This paper examines the possible health effects of exposure to EDB, as well as its regulation. The possible health effects and regulation of various chemical and physical alternatives to EDB are also examined. This paper concludes with some policy considerations pertinent to EDB.

2 5 __ __ P ~ P 84-591 ENR _-_, Congressional Research Service - The Library of Congress Cq ji 4 Washington, D.C. 20540 ETHYLENE D IBROMI DE : REGULATORY BACKGROUND James V. A i d a l a Analyst Environment and N a t u r a l R e s o u r c e s P o l i c y D i v i s i o n F e b r u a r y 8 , 1984 Revised March 2 7 , 1984 ETHYLENE DIBROMIDE : REGULATORY BACKGROUND SUMMARY On F e b r u a r y 3 , 1984, EPA announced t h e emergency s u s p e n s i o n o f EDB u s e a s a fumigant f o r r a w g r a i n and m i l l i n g machinery. T h i s a c t i o n was i s s u e d i n l i g h t o f a d d i t i o n a l d a t a c o n c e r n i n g EDB r e s i d u e s i n g r a i n - b a s e d consumer p r o d u c t s . I n September 1983 EPA had i s s u e d a r e g u l a t o r y d e c i s i o n o n l y s u s p e n d i n g EDB u s e a s a s o i l fumigant i m m e d i a t e l y , and p r o p o s i n g t o p h a s e o u t most o f i t s r e m a i n i n g u s e s o v e r t h e n e x t 12-18 months. I n September EPA c i t e d s i g n i - f i c a n t new e v i d e n c e t h a t EDB i s c o n t a m i n a t i n g g r o u n d w a t e r s u p p l i e s i n a number o f S t a t e s , and promised t o f u r t h e r i n v e s t i g a t e p o s s i b l e EDB r e s i d u e s i n f o o d . R e g i s t r a t i o n t o u s e EDB t o f u m i g a t e c i t r u s was c a n c e l l e d i n t h e September 1983 d e c i s i o n , e f f e c t i v e i n September 1984. R e s i d u e s i n t r e a t e d f r u i t have a l s o b e e n a s u b j e c t o f p u b l i c c o n c e r n ; EPA reexamined t h i s i s s u e and i n March 1984 announced i n t e r i m r e s i d u e t o l e r a n c e l e v e l s , and s e t a permanent zero-level t o l e r a n c e e f f e c t i v e i n September 1984. L a b o r a t o r y t e s t r e s u l t s h a v e shown EDB t o b e a p o t e n t c a r c i n o g e n and mutagen, and a c a u s e o f r e p r o d u c t i v e d i s o r d e r s , i n t e s t a n i m a l s . Between September 1983 and F e b r u a r y 1984, a number o f S t a t e s began t o t e s t f o r t h e p r e s e n c e o f EDB i n consumer food p r o d u c t s . Upon d i s c o v e r y o f EDB r e s i d u e s , t h e S t a t e o f F l o r i d a s t o p p e d t h e s a l e o f s p e c i f i c l o t s of t h e s e . . - p r o d u c t s , and o t h e r S t a t e s c o n s i d e r e d s i m i l a r measures. EPA had n e v e r e s t a b l i s h e d a n a l l o w a b l e r e s i d u e t o l e r a n c e f o r EDB i n t h e s e f o o d s , which l e f t t h e S t a t e s l i t t l e g u i d a n c e a s t o what c o n s t i t u t e s a s a f e o r u n s a f e l e v e l o f EDB . I n t h e F e b r u a r y 1984 announcement, EPA recommended maximum p e r m i s s i b l e r e s i d u e l e v e l s o f 900 ppb ( p a r t s p e r b i l l i o n ) on raw g r a i n p r o d u c t s , 150 ppb o n g r a i n p r o d u c t s r e q u i r i n g f u r t h e r p r o c e s s i n g ( s u c h a s a c a k e m i x ) , and 30 ppb on ready-to-eat products (such a s bread o r cookies). It i s s t i l l u n c l e a r t h e e x t e n t t o which EDB h a s b e e n used t o t r e a t c e r e a l g r a i n s . Estimates of t h e amount o f raw g r a i n t r e a t e d w i t h EDB r a n g e from 2-50%. The March 1984 announcement e s t a b l i s h e d an i n t e r i m t o l e r a n c e o f 250 ppb on c i t r u s . T h i s i s a whole f r u i t t o l e r a n c e which i s e q u i v a l e n t t o a 30 ppb level i n the edible portions. A f t e r September 1 , 1984, n o l e v e l s o f EDB r e s i d u e w i l l b e allowed o n d o m e s t i c o r imported c i t r u s and papaya. WHAT I S EDB? EDB, a p e r s i s t e n t h a l o g e n a t e d hydrocarbon, h a s been r e g i s t e r e d a s a p e s t i c i d e s i n c e 1948. i n t h i s country. Over 300 m i l l i o n pounds o f EDB a r e produced a n n u a l l y Over 20 m i l l i o n pounds a r e used a s a p e s t i c i d e . The r e - mainder i s used a s an a d d i t i v e i n l e a d e d g a s o l i n e . Of t h e 20 m i l l i o n pounds o f EDB used f o r a g r i c u l t u r a l p u r p o s e s , o v e r 90 p e r c e n t i s used a s a s o i l fumigant. was suspended i n September 1983. The u s e o f EDB a s a s o i l f u m i g a n t The remaining u s e s o f EDB were t o f u m i g a t e s t o r e d g r a i n and g r a i n m i l l i n g m a c h i n e r y , a s a fumigant t o q u a r a n t i n e c i t r u s and o t h e r t r o p i c a l f r u i t s , and f o r a number of m i n o r u s e s . Subsequent d e c i s i o n s h a v e ended v i r t u a l l y a l l EDB u s e by t h e p r e s e n t t i m e . EPA' s DECISIONS* EPA's a u t h o r i t y t o r e g u l a t e p e s t i c i d e s i s g i v e n by t h e F e d e r a l I n s e c t i c i d e , F u n g i c i d e , and R o d e n t i c i d e Act (FIFRA) . FIFRA r e q u i r e s t h a t a p e s t i c i d e b e r e g i s t e r e d w i t h EPA b e f o r e i t c a n b e used. This r e g i s t r a t i o n i s based upon a r e v i e w o f h e a l t h and s a f e t y d a t a , and i s t o g u a r a n t e e t h a t t h e p r o d u c t c a n b e used w i t h o u t u n r e a s o n a b l e a d v e r s e effects. I f l a t e r information i n d i c a t e s unreasonable adverse e f f e c t s , EPA c a n move t o suspend o r c a n c e l t h e p e s t i c i d e ' s r e g i s t r a t i o n . The September 1983 emergency s u s p e n s i o n ( t h e most r e s t r i c t i v e m e a s u r e EPA c a n t a k e under t h e law) i m m e d i a t e l y s t o p p e d t h e s a l e and d i s t r i b u t i o n o f EDB f o r s o i l f u m i g a t i o n . I n t h i s u s e i t was a p p l i e d p r i o r t o p l a n t i n g t o c o n t r o l nematodes and o t h e r s o i l i n s e c t s . As a s o i l f u m i g a n t i t was used o n c i t r u s and f r u i t t r e e s , s o y b e a n s , p i n e a p p l e s , c o t t o n , t o b a c c o , p e a n u t s , and o v e r 30 a d d i t i o n a l f r u i t and v e g e t a b l e c r o p s . Most o f t h e s e u s e s a r e c o n c e n t r a t e d i n t h e s o u t h e r n s t a t e s , C a l i f o r n i a , and Hawaii where t h e s o i l p e s t s a r e t h e g r e a t e s t problem. T e s t s have found t h e c h e m i c a l i n groundwater i n C a l i f o r n i a , F l o r i d a , ~ a w a i i ,and G e o r g i a . I n F e b r u a r y 1984 EPA announced a n emergency s u s p e n s i o n o f EDB f o r f u m i g a t i o n o f s t o r e d g r a i n and g r a i n m i l l i n g machinery. The s u s p e n s i o n o r d e r l e g a l l y h a l t s t h e s a l e , d i s t r i b u t i o n and a c t u a l u s e o f EDB p r o d u c t s f o r these purposes. EPA a l s o recommended maximum a c c e p t a b l e l e v e l s o f EDB r e s i d u e s i n t h r e e c a t e g o r i e s of g r a i n - b a s e d f o o d s : raw g r a i n i n t e n d e d f o r human consumption (900 p p b ) ; consumer p r o d u c t s r e q u i r i n g f u r t h e r p r e p a r a t i o n *For t h e c o n v e n i e n c e o f t h e r e a d e r , a c h r o n o l o g y o f e v e n t s i s g i v e n a t t h e end o f t h i s p a p e r . (150 P P ~ ) ;and r e a d y - t o - e a t p r o d u c t s (30 ppb). EPA a l s o i n i t i a t e d a c t i o n s t o remove impediments t o F e d e r a l enforcement of t h e recommended l e v e l s . These a c t i o n s i n c l u d e r e v o k i n g t h e e x i s t i n g exemption from t o l e r a n c e r e q u i r e m e n t s f o r r e s i d u e s o f EDB r e s u l t i n g from g r a i n f u m i g a t i o n , and r e v o k i n g t o l e r a n c e s f o r i n o r g a n i c bromide r e s u l t i n g from EDB f u m i g a t i o n o f g r a i n and o t h e r commodities. The September 1983 EPA c a n c e l l a t i o n o r d e r a l s o o r d e r e d a phase o u t , by September 1 , 1984, o f t h e u s e o f EDB f o r q u a r a n t i n e f u m i g a t i o n o f c i t r u s f r u i t s , t r o p i c a l f r u i t s such a s mangos and papaya, and o t h e r f r u i t s and v e g e t a b l e s which c a n b e t h e h o s t f o r t r o p i c a l f r u i t f l i e s . The i n t e r i m p e r i o d was allowed t o p r o v i d e time f o r f u r t h e r development and implement a t i o n of a l t e r n a t i v e s . On March 2 , 1984, EPA announced i n t e r i m t o l e r a n c e l e v e l s of 250 ppb f o r c i t r u s and papaya, and allowed u s e t o c o n t i n u e u n t i l September 1. A f t e r t h a t d a t e , t h e s e w i l l be a z e r o t o l e r a n c e f o r t h e s e f r u i t s , and no f u r t h e r EDB u s e w i l l be a l l o w e d . Gamma i r r a d i a t i o n and c o l d s t o r a g e t r e a t m e n t s a r e a l t e r n a t i v e s c u r r e n t l y under c o n s i d e r a t i o n ( s e e CRS w h i t e paper: " P r e s e r v a t i o n of Food by I r r a d i a t i o n t t by Donna P o r t e r , J u n e 21, 1983). Much o f t h e fumigated f r u i t i s s h i p p e d t o J a p a n , which r e q u i r e s some k i n d of q u a r a n t i n e t r e a t m e n t . Some v e r y m i n o r u s e s of EDB w i l l be allowed t o c o n t i n u e , though l a b e l changes w i l l be r e q u i r e d . These i n c l u d e t h e f u m i g a t i o n o f s t o r e d b e e h i v e s and h i v e p l a t f o r m s t o c o n t r o l wax moths; u s e on v a u l t - s t o r e d and f u r n i t u r e ; and t h e U.S. Program. clothing Department o f A g r i c u l t u r e ' s J a p a n e s e B e e t l e These a c t i o n s a r e p a r t of EPA's i n v e s t i g a t i o n o f EDB u n d e r t h e proc e d u r e c a l l e d R e b u t t a b l e P r e s u m p t i o n A g a i n s t R e g i s t r a t i o n (RPAR). his f o r m a l p r o c e s s i s s t a r t e d when t h e Agency h a s e v i d e n c e t h a t a ~ e s t i c i d e may c a u s e u n r e a s o n a b l e a d v e r s e e f f e c t s i n humans o r t h e e n v i r o n m e n t . In 1975, t h e N a t i o n a l Cancer I n s t i t u t e i s s u e d a n o t i c e t h a t EDB a p p e a r e d t o induce cancer i n l a b o r a t o r y animals. I n 1977, f o l l o w i n g e v i d e n c e t h a t EDB a l s o posed a d d i t i o n a l r i s k s , EPA b e g a n t h e RPAR r e v i e w . I n December 1980, a f t e r f u r t h e r r e s e a r c h on t h e u s e o f EDB, and a f t e r a n a l y z i n g t h e p u b l i c comments c o n c e r n i n g r i s k s and b e n e f i t s , t h e Agency i s s u e d a proposed d e c i s i o n t o cancel t h e p e s t i c i d e f o r fumigation of s t o r e d g r a i n , m i l l i n g machinery and f e l l e d l o g s , and t o p h a s e o u t t h e u s e o f EDB f o r c i t r u s and v e g e t a b l e q u a r a n t i n e f u m i g a t i o n o v e r a p e r i o d o f two y e a r s . I n t h i s 1980 p r o p o s a l , u s e o f EDB f o r s o i l f u m i g a t i o n was t o b e r e t a i n e d s i n c e t h i s u s e d i d n o t a p p e a r t o r e s u l t i n s i g n i f i c a n t human e x p o s u r e . Between 1980-83, d i s c o v e r y o f g r o u n d w a t e r c o n t a m i n a t i o n by EDB caused EPA t o p r o p o s e an end t o t h i s use a s well. FIFRA a l l o w s m a n u f a c t u r e r s and r e g i s t r a n t s of EDB p r o d u c t s t o a p p e a l EPA'S d e c i s i o n s . None o f t h e suspended u s e s h a s b e e n a p p e a l e d . The c a n c e l l a t i o n o r d e r f o r f e l l e d l o g f u m i g a t i o n , which a c c o u n t s f o r a s m a l l amount o f EDB u s e , h a s b e e n a p p e a l e d by t h e s t a t e o f Colorado. Appealing a c a n c e l l a t i o n o r d e r i n i t i a t e s h e a r i n g s which r e v i e w t h e r i s k s and b e n e f i t s of t h e p e s t i c i d e p r o d u c t s . cancellation hearings. complete. Uses of t h e p e s t i c i d e a r e a l l o w e d d u r i n g t h e These h e a r i n g s u s u a l l y t a k e one o r two y e a r s t o The u s e o f EDB i n g a s o l i n e was n o t c o n s i d e r e d a s p a r t of t h e s e decisions. Used i n g a s o l i n e , EDB k e e p s l e a d from c o l l e c t i n g on a n e n g i n e ' s c y l i n d e r w a l l s . C o n c e n t r a t i o n s i n g a s o l i n e a r e less t h a n 0.5 p e r c e n t . Acc o r d i n g t o EPA'S September 1983 p r e s s r e l e a s e , p r e l i m i n a r y a n a l y s i s of exposure t o EDB f r a n g a s o l i n e v a p o r s shows t h a t t h e s e e x p o s u r e s a r e much lower t h a n t h o s e r e s u l t i n g £ r a n a g r i c u l t u r a l u s e s . However, some o b s e r v e r s b e l i e v e t h a t ambient EDB l e v e l s f r a n g a s o l i n e u s e a r e n o t t r i v i a l . The S t a t e o f New York e s t i m a t e d h i g h e r EDB r i s k s t h a n EPA d i d , based i n p a r t on an a s s e s s m e n t o f t h e s e e s t i m a t e d ambient e x p o s u r e s . EDB R e s i d u e s i n Food As p a r t o f a r e g i s t r a t i o n d e c i s i o n , EPA d e c i d e s what amount of a p e s t i c i d e w i l l p r e s e n t no u n r e a s o n a b l e r i s k t o t h e e v e n t u a l consumers o f t h e t r e a t e d crop. These a r e " p e s t i c i d e r e s i d u e s 1 ' which a r e g r a n t e d a " t o l e r a n c e " from EPA. T h i s i s t h e amount EPA c a l c u l a t e s a s s a f e assuming a l i f e t i m e of e x p o s u r e v i a t h e f o o d s t u f f . EPA g r a n t s t h e t o l e r a n c e , b u t i t i s e n f o r c e d by t h e Food and Drug A d m i n i s t r a t i o n . I n 1956, EDB g r a i n f m i g a t i o n u s e s were g r a n t e d an exemption from t o l e r a n c e r e q u i r e m e n t s , b e c a u s e i t was b e l i e v e d t h a t t h e p e s t i c i d e d i s s i p a t e d d u r i n g t h e p r o c e s s i n g of t h e food. shows t h i s assuniption t o b e i n c o r r e c t . Modern d e t e c t i o n t e c h n o l o g y now EDB t o l e r a n c e s on c i t r u s were n o t exempted i n 1956 o r any l a t e r time; a n i n t e r i m t o l e r a n c e was g r a n t e d i n March 1984. EPA h a s known t h a t EDB d o e s n o t e n t i r e l y d i s s i p a t e f o r some y e a r s . T h e i r 1980 EDB r e g u l a t o r y s u p p o r t document d i s c u s s e s 1978 s t u d i e s showing t h e p r e s e n c e o f EDB i n f l o u r and baked goods. According t o EPA'S 1983 s u p p o r t document, t h e 1980 document somewhat u n d e r e s t i m a t e d t h e r e s i d u e s o f EDB i n s t o r e d g r a i n . I n t h e 1983 document, EPA s t a t e d t h a t t h e r i s k e s t i m a t e s from b u l k g r a i n f u m i g a t i o n were found t o p r e s e n t t h e m a j o r known d i e t a r y r i s k from EDB. The 1983 r e p o r t found EDB l e v e l s i n 20 o f 22 f l o u r s a m p l e s ; t h e l e v e l s ranged from none d e t e c t e d t o 4200 ppb ( p a r t s p e r b i l lion). I n t h e 20 samples found w i t h E D B , r e s i d u e l e v e l s i n b i s c u i t s baked from t h e f l o u r d e t e c t e d w i t h EDB r a n g e d from none d e t e c t a b l e t o 260 ppb, and a v e r a g e d 3 6 ppb. I n h e a r i n g s b e f o r e t h e House Government O p e r a t i o n s Committee on March 5 and 6 , 1984, i t was r e p o r t e d t h a t t h e r e was some knowledge o f EDB r e s i d u e s i n food a s e a r l y a s 1965. During t h i s t i m e EPA d i d n o t i s s u e a t o l e r a n c e f o r EDB r e s i d u e s o n c e r e a l g r a i n s o r c i t r u s , n o r were t h e r e g i s t r a n t s r e q u i r e d t o submit a n application. C o o r d i n a t i o n Between EPA and FDA Allowable r e s i d u e l e v e l s a r e d e t e r m i n e d by EPA b u t a r e e n f o r c e d by t h e Food and Drug A d m i n i s t r a t i o n (FDA). For raw a g r i c u l t u r a l c o m m o d i t i e s , s u c h a s unprocessed g r a i n o r c i t r u s , t h e t o l e r a n c e i s e n f o r c e d u n d e r a u t h o r i t y o f FIFRA. For p r o c e s s e d f o o d s , s u c h a s wheat f l o u r , t h e t o l e r a n c e i s e n f o r c e d under a u t h o r i t y o f t h e Food, Drug and Cosmetic Act (FDCA), This i s because a p e s t i c i d e r e s i d u e i s c o n s i d e r e d a "food a d d i t i v e " a f t e r t h e r a w commodity h a s been p r o c e s s e d . S e c t i o n 409 of t h e FDCA i n c l u d e s t h e Delaney Amendment, which d o e s n o t p e r m i t food a d d i t i v e s which have been e s t a b l i s h e d a s a n i m a l carcinogens. However, S e c t i o n 402 o f t h e FDCA s t a t e s t h a t a f o o d s t u f f c a n n o t b e c o n s i d e r e d a d u l t e r a t e d i f t h e r e s i d u e l e v e l i n t h e p r o c e s s e d food i s t h e same o r l e s s t h a n t h e l e v e l allowed on t h e raw a g r i c u l t u r a l commodity. As a r e s u l t o f EDB l e v e l s d e c l i n i n g d u r i n g p r o c e s s i n g ( d u e t o a e r a t i o n , baking, e t c . ) , t h e Delaney Amendment i s i n t e r p r e t e d n o t t o a p p l y . However, once EPA s e t s a t o l e r a n c e f o r t h e raw a g r i c u l t u r a l commodity, t h i s a l s o d e t e r m i n e s , t o a n e x t e n t , t h e c e i l i n g of a l l o w a b l e r e s i d u e s i n p r o c e s s e d foods. A r e l a t i v e l y h i g h t o l e r a n c e f o r t h e raw commodity might p r e v e n t a c t i o n s a g a i n s t p r o c e s s e d foods a t l e v e l s above E P A ' s recommendations. S e t t i n g a low r e s i d u e l e v e l aimed a t t h e r e t a i l consumer l e v e l c o u l d l e a v e much s t o r e d g r a i n t o be c o n s i d e r e d " a d u l t e r a t e d " . To avoid t h e s e dilemmas, EPA r e l i e s on " a c t i o n l e v e l s " t o be used by FDA. These l e v e l s a r e F e d e r a l l y e n f o r c e a b l e a s e v i d e n c e t h a t "good manu- f a c t u r i n g p r a c t i c e s " h a v e been followed. Such d e c i s i o n s a r e a d m i n i s t r a t i v e o n e s i s s u e d by FDA w i t h r e l a t i v e l y l i t t l e p r o c e d u r a l r e q u i r e m e n t s . S t a t e s r e q u i r e FDA a c t i o n l e v e l s t o b e b i n d i n g . Many Residues found t o b e above t h e FDA a c t i o n l e v e l s would t r i g g e r FDA i n v e s t i g a t i o n a s t o whether o r n o t good m a n u f a c t u r i n g p r a c t i c e s were f o l l o w e d . However, e s t a b l i s h i n g a c t i o n l e v e l s i n s t e a d of r e s i d u e t o l e r a n c e s d o e s r a i s e some q u e s t i o n s o f uniform e n f o r c e m e n t o f t h e s e s t a n d a r d s . A l s o , some e n v i r o n m e n t a l g r o u p s have t h r e a t e n e d l i t i g a t i o n s h o u l d EPA n o t o n l y revoke t h e 1956 exemption from t o l e r a n c e s r e q u i r e m e n t s , b u t a l s o e s t a b l i s h a z e r o t o l e r a n c e f o r f i n i s h e d food p r o d u c t s which a r e r e a d y f o r human consumption. Quarantine Fumigation EPA's September 1983 d e c i s i o n on EDB a s a q u a r a n t i n e t r e a t m e n t f o r c i t r u s and t r o p i c a l f r u i t s was t o c a n c e l t h i s r e g i s t e r e d u s e e f f e c t i v e September 1 , 1984. EPA e x p l a i n e d t h a t t h i s phase-out p e r i o d was needed t o c l a r i f y b o t h t h e a v a i l a b i l i t y and a c c e p t a b i l i t y o f a l t e r n a t i v e q u a r a n t i n e t r e a t m e n t s . EPA f e l t t h a t more i n f o r m a t i o n was needed a b o u t r e s i d u e s , a l t e r n a t i v e s , and international trade. I n March 1984, EPA announced a n i n t e r i m r e s i d u e t o l e r a n c e l e v e l of 250 ppb on t h e whole f r u i t , and a s o f September 1, 1984, no EDB r e s i d u e s w i l l b e a l l o w e d o n c i t r u s and papaya. The e x t e n t o f f u m i g a t i o n v a r i e s . * F o r example, EPA e s t i m a t e s t h a t Texas fumigates approximately 20 percent of i t s exported c i t r u s , while C a l i f o r n i a r e q u i r e s a l l c i t r u s imported from F l o r i d a t o b e f u m i g a t e d (however, C a l i f o r n i a r e c e n t l y d e c i d e d t o d e n y e n t r y t o EDB-treated fruit). E s t i m a t e s o f t h e amount o f e x p o r t e d C a l i f o r n i a c i t r u s which i s fumigated i n c l u d e : 17 p e r c e n t o f t h e o r a n g e s , 35 p e r c e n t o f g r a p e f r u i t , and 44 p e r c e n t of o t h e r f r e s h c i t r u s . It i s e s t i m a t e d t h e economic b e n e f i t s * o f EDB t o t h e c i t r u s i n d u s t r y a r e some $30 m i l l i o n i n t r a d e t h a t c o u l d b e l o s t i f t h e p e s t i c i d e i s banned. Some $24.7 m i l l i o n o f t h i s c o n s i s t s o f g r a p e f r u i t e x p o r t s t o J a p a n . For t h e a v e r a g e U.S. consumer o f c i t r u s and t r o p i c a l f r u i t s , t h e most l i k e l y s o u r c e o f EDB e x p o s u r e i s from imported p r o d u c t s . Q u a r a n t i n e r e q u i r e m e n t s f o r c i t r u s and t r o p i c a l f r u i t s p r e v e n t t h e s p r e a d of p o t e n t i a l l y d e v a s t a t i n g i n f e s t a t i o n s o f s e v e r a l s p e c i e s o f f r u i t *These e s t i m a t e s a r e g i v e n i n EPA's " E t h y l e n e Dibromide: P o s i t i o n Document 4 " , September 1983. flies. The U.S. t h e mainland U.S. U.S. r e q u i r e s most f r e s h c i t r u s and t r o p i c a l f r u i t s s h i p p e d i n t o t o b e fumigated w i t h EDB. Some f r u i t s shipped w i t h i n t h e t o Texas, New Mexico, A r i z o n a , and C a l i f o r n i a must a l s o b e f u m i g a t e d . Thus, d e c i s i o n s on EDB p o t e n t i a l l y a f f e c t : ( a ) i m p o r t s from L a t i n American, Caribbean and M e d i t e r r a n e a n n a t i o n s ; ( b ) e x p o r t s t o J a p a n ; and ( c ) some f r u i t s s h i p p e d i n i n t e r s t a t e commerce. EPA e s t i m a t e s t h a t o n l y a s m a l l p e r c e n t a g e of a l l c i t r u s consumed i n t h i s c o u n t r y i s t r e a t e d w i t h EDB. Of t h e 5.8 b i l l i o n pounds o f c i t r u s con- sumed, a b o u t 40 m i l l i o n pounds i s imported f r e s h f r u i t (most i s f u m i g a t e d ) , and about 5 5 m i l l i o n pounds i s fumigated f o r d o m e s t i c i n t e r s t a t e q u a r a n t i n e . T h i s i s a b o u t 2% o f t h e t o t a l consumed. C i t r u s intended f o r processing i n t o j u i c e i s not fumigated. According t o EPA, r e s i d e n t s o f t h e Southwest, w i t h i n c r e a s e d p o r t i o n s o f EDB-treated c i t r u s i n t h e i r d i e t s , were assumed t o have been exposed t o g r e a t e r amounts o f EDB. Average EDB r e s i d u e l e v e l s i n e d i b l e p o r t i o n s of c i t r u s , c o l l e c t e d by EPA from S u n b e l t s u p e r m a r k e t s , h a v e ranged from a 5 1 ppb l e v e l i n g r a p e f r u i t t o a 48 ppb l e v e l i n o r a n g e s . Recently, C a l i f o r n i a o f f i c i a l s have r e p o r t e d F l o r i d a c i t r u s pulp t o c o n t a i n an average o f 200 ppb o v e r t h e l a s t f i v e y e a r s . EPA e s t i m a t e s t h e i n c r e a s e d c a n c e r r i s k o v e r a l i f e t i m e o f e a t i n g t r e a t e d c i t r u s i s 1 i n 100,000 from EDB f o r t h e a v e r a g e consumer. A l t e r n a t i v e s t o e t h y l e n e dibromide include t h e use of o t h e r chemicals such a s methyl bromide. Gamma i r r a d i a t i o n o f c i t r u s , a l o n g w i t h c o l d s t o r a g e of t h e f r u i t , a r e a l s o new t e c h n i q u e s under development. The FDA i s c u r r e n t l y l o o k i n g a t t h e method o f i r r a d i a t i n g f r u i t and v e g e t a b l e s as a n a l t e r n a t i v e t o q u a r a n t i n e f u m i g a t i o n , though a n y new method must b e approved b o t h by t h e U.S. Department o f A g r i c u l t u r e and t h e i m p o r t i n g S t a t e s . Some of t h e a l t e r n a t i v e , n o n - p e s t i c i d e c o n t r o l methods ( e . g , c o l d s t o r a g e t r e a t m e n t ) a l r e a d y h a v e been approved by FDA b u t a w a i t g r e a t e r i n d u s t r y and consuner a c c e p t a n c e . U n t i l EDB-use i s banned o r a n e f f e c t i v e a l t e r n a t i v e p r o d u c t o r method i s m a r k e t e d , EDB w i l l remain as a m a j o r q u a r a n t i n e f u m i g a n t o f c h o i c e o f many e x p o r t i n g and i m p o r t i n g c o u n t r i e s . OCCUPATIONAL EXPOSURE On O c t o b e r 7 , 1983 t h e O c c u p a t i o n a l S a f e t y and H e a l t h A d m i n i s t r a t i o n (OSHA) proposed a s t r i n g e n t r e v i s i o n ( 4 8 CFR 45956) i n t h e p r e s e n t s t a n d a r d r e g u l a t i n g employee e x p o s u r e t o EDB. l i m i t o f 2 0 ppm a arts The p r o p o s a l would r e d u c e t h e p r e s e n t p e r m i l l i o n ) o f a i r t o .1 ppm ( t o compare t o t h e food l e v e l s d i s c u s s e d e a r l i e r , 20 ppm - i s e q u i v a l e n t t o 20,000 ppb and .1 - - - ppm i s e q u a l t o 1 0 0 ppb). The p r o p o s a l would a l s o add r e q u i r e m e n t s f o r e x p o s u r e m o n i t o r i n g , employee e d u c a t i o n , and t h e l i k e . OSHA e s t i m a t e s t h a t 56,000 w o r k e r s a r e exposed t o EDB f o r v a r y i n g p e r i o d s ; o t h e r s have e s t i m a t e d t h e number o f exposed w o r k e r s a t 100,000 ( t h e s e e s t i m a t e s i n c l u d e g r a i n u s e e x p o s u r e s which h a v e now b e e n s u s p e n d e d ) . I n t e s t i m o n y a t c o n g r e s s i o n a l h e a r i n g s ( ~ e p t .1 3 , 1983 h e a r i n g s b e f o r e t h e House E d u c a t i o n and Labor Subcommittee on Labor S t a n d a r d s ) e x p r e s s e d d i s s a t i s f a c t i o n w i t h t h e OSHA p r o p o s a l . , l a b o r groups have They b e l i e v e t h e proposed m o n i t o r i n g arid t r a i n i n g r e q u i r e m e n t s t o be i n a d e q u a t e . Of s p e c i a l c o n c e r n i s t h a t t h e p r o p o s a l exempts employers t h a t e x p o s e t h e i r employees t o EDB f o r l e s s t h a n 30 d a y s p e r y e a r from r e q u i r e m e n t s t o i n s t a l l f e a s i b l e e n g i n e e r i n g c o n t r o l s ( s u c h a s v e n t i l a t i o n f a n s ) o r adopt work p r a c t i c e c o n t r o l s ( s u c h a s p r o v i d i n g more time between f u m i g a t i o n and worker r e - e n t r y ) . f i c i a l s view t h i s exemption a s t o o broad and u n n e c e s s a r y . many workers exposed t o EDB. Labor of- I t c o u l d exempt Furthermore, t h e s e simple enginering c o n t r o l s and r e v i s e d work p r a c t i c e s h a v e b e e n r e q u i r e d f o r o v e r two y e a r s i n t h e S t a t e o f C a l i f o r n i a w i t h r e p o r t e d l y l i t t l e n e g a t i v e impact on employers. I n s t e a d o f t h e s e c o n t r o l m e a s u r e s , OSHA's p r o p o s a l would r e q u i r e p e r s o n a l p r o t e c t i v e d e v i c e s ( r e s p i r a t o r s ) t o b e used by w o r k e r s . The u n i o n s m a i n t a i n t h a t r e s p i r a t o r y p r o t e c t i o n i s o f t e n i n e f f e c t i v e , c a n n o t b e used by e v e r y o n e , and p r o v i d e s no p r o t e c t i o n a g a i n s t s k i n a b s o r p t i o n . The o t h e r major c o m p l a i n t i s t h a t t h e e x p o s u r e l e v e l s w i l l n o t b e immediately r e d u c e d . I n l i g h t o f t h e h e a l t h r i s k s o f EDB, t h e u n i o n s have r e p e a t e d l y p e t i t i o n e d OSHA t o i s s u e a n emergency t e m p o r a r y s t a n d a r d t o r e d u c e e x p o s u r e immediately. OSHA h a s d e n i e d t h e s e p e t i t i o n s e x p l a i n i n g t h a t t h e r e i s no documented e v i d e n c e o f a n emergency, a l t h o u g h s u c h measures h a v e b e e n r e commended t o OSHA by t h e N a t i o n a l I n s t i t u t e of O c c u p a t i o n a l S a f e t y and H e a l t h (NIOSH) . The c u r r e n t s t a n d a r d o f 20 ppn i s w i t h i n t h e r a n g e o f e x p o s u r e which induced tumors i n t h e N a t i o n a l Cancer I n s t i t u t e a n i m a l i n h a l a t i o n s t u d i e s . Some s t u d i e s showed t u n o r - c a u s i n g e f f e c t s t o o c c u r a t 10 ppm, w i t h a s t r o n g d o e s - r e s p o n s e r e l a t i o n s h i p up t o t h e 40 ppn l e v e l , Finding a carcinogenic e f f e c t i n l a b o r a t o r y animals a t l e v e l s w i t h i n t h e permissible occupational exposure i s unusual. T h i s f i n d i n g of adverse e f f e c t s a t r e l a t i v e l y low l e v e l s i s p a r t i a l l y behind t h e NIOSH recommendation f o r an emergency s t a n d a r d t o immediately reduce a l l o w a b l e exposure l e v e l s . EPA, under FIFRA, h a s no a u t h o r i t y c o n c e r n i n g o c c u p a t i o n a l exposure s t a n d a r d s t o EDB. However, a s EPA h a s suspended almost a l l u s e s o f EDB, t h i s makes t h e OSHA r u l e r e l a t i v e l y moot. The h i g h e s t exposure groups a r e t h o s e who work i n a g r i c u l t u r e - r e l a t e d s i t u a t i o n s - - g r a i n warehouses, and t h e l i k e . m i l l s , food The EPA a c t i o n s on c i t r u s and g r a i n f u m i g a t i o n u s e s e f f e c t i v e l y s t o p most of t h e exposure t o such h i g h r i s k groups. As a r e s u l t , l a b o r union r e p r e s e n t a t i v e s have t a k e n an i n t e r e s t i n n o t o n l y t h e rulemaking a c t i v i t y o f OSHA, b u t a l s o t h a t o f EPA. Related Issues Some o f t h e c o n f u s i o n about a p p r o p r i a t e r e s p o n s e s i n l i g h t o f EDB r e s i d u e s h a s been r e s o l v e d by EPA's g u i d e l i n e s . N e v e r t h e l e s s , a t l e a s t two i s s u e s remain: 1) how s a f e a r e l e v e l s of EDB which a r e below t h e s u g g e s t e d t o l e r a n c e ; and 2) i s t h i s s i t u a t i o n unique, o r w i l l i t b e r e p e a t e d i n t h e f u t u r e with o t h e r p e s t i c i d e s ? The f i r s t q u e s t i o n , "How s a f e i s s a f e , " h a s no obvious answer. Many o b s e r v e r s compare EDB r i s k s t o o t h e r widespread, p o t e n t i a l c a n c e r - c a u s i n g t r a c e contaminants. For example, a f l a t o x i n , a v e r y p o t e n t animal c a r c i n o g e n (more p o t e n t t h a n EDB), i s a n a t u r a l l y - o c c u r r i n g s u b s t a n c e i n many foods ( e s p e c i a l l y g r a i n ) , and h a s an a l l o w a b l e r e s i d u e l e v e l of 20 p a r t s p e r b i l l i o n i n food. T h i s l e v e l of a l l o w a b l e a f l a t o x i n may add some perspec- t i v e t o proposed EDB t o l e r a n c e l e v e l s . However, o v e r a l l F e d e r a l r e g u l a t o r y pol i c y h a s been t h a t avo i d a b l e e x p o s u r e s t o animal c a r c i n o g e n s s h o u l d b e minimized. As a r e s u l t , t o l e r a n c e l e v e l s a r e l i k e l y t o remain c o n t r o v e r s i a l u n t i l EDB r e s i d u e s i n t h e food s u p p l y a p p r o a c h z e r o ( e s t i m a t e d t o t a k e 3-5 years). The second i s s u e i s more g e n e r a l and c o n c e r n s t h e o v e r a l l r e s i d u e l e v e l s e t t i n g process. There a r e a v a r i e t y of p e s t i c i d e s whose r e s i d u e t o l e r a n c e s w e r e developed and g r a n t e d w i t h o u t t h e b e n e f i t s o f modern d e t e c t i o n methods o r of what a r e now c o n s i d e r e d e s s e n t i a l c h r o n i c h e a l t h d a t a . GAO and Congress have i s s u e d numerous r e p o r t s i n t h e l a s t 5-10 y e a r s s t r o n g l y c r i t i c i z i n g EPA's t o l e r a n c e - s e t t i n g p r o c e d u r e s and program. The Agency's program h a s been con- t i n u a l l y upgraded i n l i g h t o f t h e s e r e p o r t s and recommendations from o t h e r sources. However, i t i s l i k e l y t h a t o t h e r p e s t i c i d e s which h a v e b e e n i n widespread u s e f o r many y e a r s w i l l r a i s e s i m i l a r p o l i c y i s s u e s i n t h e f u t u r e - how t i m e l y h a s EPA b e e n i n i t s r e v i e w o f t h e s e o l d e r p r o d u c t s , a n d , s h o u l d a l l o w a b l e r e s i d u e l e v e l s b e r e v i s e d i n l i g h t of new d a t a ? The r e c e n t 11 d i s c o v e r y ' ' o f EDB and i t s l a c k o f e s t a b l i s h e d t o l e r a n c e s may b r i n g t h e s e i s s u e s more d i r e c t l y i n t o t h e FIFRA r e a u t h o r i z a t i o n d e b a t e d u r i n g t h e second s e s s i o n o f t h e 9 8 t h Congress. O t h e r o l d e r p e s t i c i d e s which a r e p o s s i b l e a l t e r n a t i v e s t o EDB may a l s o be hazardous. There i s l e s s d a t a a v a i l a b l e about some o f t h e s e o t h e r pes- t i c i d e s , and i t w i l l t a k e y e a r s b e f o r e a l l have b e e n f u l l y c h a r a c t e r i z e d with complete r e g i s t r a t i o n d a t a . Methyl bromide h a s been r e p o r t e d i n t h e - washington Post a s being p o s i t i v e i n a r e c e n t animal cancer t e s t . t e t r a c h l o r i d e h a s been under EPA's RPAR r e v i e w s i n c e 1980. Carbon For more i n f o r - m a t i o n about h e a l t h e f f e c t s o f EDB and i t s a l t e r n a t i v e s , s e e CRS w h i t e p a p e r : " E t h y l e n e ~ i b r o m i d e " , J a n u a r y 2 6 , 1984, by Michael simpson. EDB CHRONOLOGY* S t u d i e s f i r s t document EDB's t o x i c i t y t o a n i m a l s . Ethylene dibromide introduced a s a p e s t i c i d e . Congress amends t h e F e d e r a l Food, Drug, Cosmetic A c t , mandating t h e s e t t i n g o f s a f e t o l e r a n c e l e v e l s f o r p e s t i c i d e s i n foods. FDA r u l i n g exempts bromide f u m i g a n t s such a s EDB from regulation regarding pesticide residue standards. This was based on t h e b e l i e f t h a t t h e p e s t i c i d e s would be d i s s i p a t e d i n t h e p r o c e s s i n g of food. Delaney Amendment t o t h e Food, Drug and Cosmetic Act banning t h e u s e of a n y c a r c i n o g e n ( c a n c e r - c a u s i n g a g e n t ) a s a food a d d i t i v e . Environrnenal P r o t e c t i o n Agency e s t a b l i s h e d . OSHA i s s u e s a 20 ppm s t a n d a r d f o r EDB a s a maximum s a f e e x p o s u r e l e v e l f o r workers o v e r a n 8 h o u r d a y . N a t i o n a l Cancer I n s t i t u t e ( N C I ) , i n a " ~ e m o of ~ l e r t " , warns t h a t EDB i s a p o t e n t c a r c i n o g e n . F i n a l N C I r e p o r t on c a n c e r h a z a r d of EDB. Environmental Defense Fund p e t i t i o n s EPA t o i n i t i a t e R e b u t a b l e P r e s u m p t i o n A g a i n s t R e g i s t r a t i o n (WAR) p r o c e s s , under FIFRA. NIOSH recaumends l o w e r i n g OSHA's 20 p p s t a n d a r d f o r EDB . EPA p u b l i s h e s n o t i c e s t a r t i n g RPAR p r o c e s s f o r EDB i n r e s p o n s e t o EDF p e t i t i o n . F i n a l N C I r e p o r t s t a t e s t h a t EDB must be c o n s i d e r e d c a p a b l e of c a u s i n g c a n c e r i n humans. The p e s t i c i d e DBCP i s banned, c a u s i n g i n c r e a s e d r e l i a n c e on t h e a l t e r n a t i v e EDB a s a p e s t i c i d e . Some 53 ccmpanies n a t i o n w i d e make 122 p r o d u c t s c o n t a i n i n g EDB . * T h i s c h r o n o l o g y i s based p r i m a r i l y on m a t e r i a l p r e p a r e d f o r t h e S e n a t e Environment and p u b l i c Works Committee. - Decanber 10 EPA announces a v a i l a b i l i t y of f i r s t p o s i t i o n document s e t t i n g f o r t h EPA'S r e v i e w o f t h e e v i d e n c e c o n c e r n i n g EDB: "Notice o f P r e l i m i n a r y D e t e m i n a t i o n Concluding t h e RPAR", P o s i t i o n Document 213." The Agency c o n c l u d e d t h a t t h e presumptions o f o n c o g e n c i t y , m u t a g e n i c i t y , and r e p r o d u c t i v e e f f e c t s were n o t r e b u t t e d , and p r o p o s e s a n end t o EDB use except f o r s o i l fumigation. - April EPA h a s g a t h e r e d a l l n e c e s s a r y s c i e n t i f i c i n f o r m a t i o n o n EDB t o p r e p a r e f i n a l RPAR d e c i s i o n . I n t e r n a l EPA s t u d y f i n d s t h a t a t e x i s t i n g maximum l e v e l s o f p e r m i t t e d e x p o s u r e , t h e o r e t i c a l l y , 999 workers o u t of 1000 c o u l d c o n t r a c t c a n c e r s . EDB r i s k termed o n e o f t h e h i g h e s t EPA h a s ever confronted. - C a l i f o r n i a OSHA p r o p o s e s a 15 ppb s t a n d a r d f o r EDB September ( f o r EDB v a p o r i n ambient a i r ) . F e d e r a l OSHA s t a n d a r d i s 20 p p . ( C a l i f o r n i a s t a n d a r d o v e r 1000-fold s t r i c t e r . ) - Autumn White House O f f i c e o f S c i e n c e and Technology t a s k f o r c e o n EDB formed t o s t u d y problem. October OSHA. - NIOSH r e a f f i r m s 1977 c a n c e r a s s e s s m e n t i n l e t t e r t o - - D r a f t o f EPA P o s i t i o n Document 4 completed Office June 10 o f P e s t i c i d e Programs c o m p l e t e s development of proposed f i n a l d e c i s i o n on EDB and f o r w a r d s t o A s s i s t a n t A d m i n i s t r a t o r Todhunter. J u l y 27 - F l o r i d a b a n s EDB f o r u s e a s a s o i l f u m i g a n t . - September 13 House E d u c a t i o n 6 Labor S u b c a m i t t e e o n Labor S t a n d a r d s h o l d s h e a r i n g o n EDB workplace h a z a r d s . - September 26 House Government. O p e r a t i o n s S u b c m m i t t e e on Energy, Environment and N a t u r a l Resources h o l d s h e a r i n g o n EPA1s P e s t i c i d e Registration Activities. - P o s i t i o n Document 4 made p u b l i c , p r e s e n t s September 27 Agency's f i n a l d e t e r m i n a t i o n r e g a r d i n g RPAR: s u s p e n s i o n o r d e r f o r u s e o f EDB a s a s o i l f u m i g a n t ; c a n c e l l a t i o n o r d e r f o r u s e o f EDB a s a s p o t and g r a i n f u m i g a n t , and c a n c e l l a t i o n o r d e r f o r EDB u s e a s a q u a r a n t i n e f u m i g a n t , e f f e c t i v e 9 / 1 / 8 4 . October 1 - EPA ban - on EDB a s a s o i l fumigant g o e s i n t o e f f e c t . F l o r i d a o r d e r s s t o p s a l e o f grain-based December 20 w i t h d e t e c t a b l e l e v e l s o f EDB ( g r e a t e r t h a n 1 ppb). products - January 4 Spot checks by F e d e r a l a g e n c i e s f i n d r e s i d u e s of EDB i n c e r t a i n foods around t h e n a t i o n , c o n c e r n r e g a r d i n g EDB grows. - January 5 EPA announces i t i s c o n s i d e r i n g an emergency s u s p e n s i o n o f g r a i n and m i l l i n g u s e s , s t a r t i n g proceedings t o revoke 1956 g r a i n t o l e r a n c e a c t i o n l e v e l exemption, and c o n t i n u i n g work on s e t t i n g a t o l e r a n c e . January 9 - C a l i f o r n i a c l o s e s i t s borders t o f r u i t t r e a t e d w i t h EDB a f t e r c o n t i n u i n g t o d e t e c t h i g h l e v e l s of c o n t a m i n a t i o n i n pulp. - J a n u a r y 10 EPA, USDA, food i n d u s t r y o f f i c i a l s , and o t h e r s e n i o r a d m i n i s t r a t i o n o f f i c i a l s hold emergency meeting about growing EDB c o n t a m i n a t i o n h a z a r d s . February 3 - EPA announces emergency s u s p e n s i o n o f g r a i n u s e s of EDB and recommends a c c e p t a b l e r e s i d u e l e v e l s i n raw g r a i n (900 ppb), p r o d u c t s r e q u i r i n g f u r t h e r p r o c e s s i n g b e f o r e e a t i n g (150 ppb), and ready-to-eat p r o d u c t s ( 3 0 ppb). - EPA announces i n t e r i m t o l e r a n c e of 250 ppb on c i t r u s March 2 and papaya whole f r u i t , which i s e q u i v a l e n t t o a 30 ppb l e v e l i n t h e e d i b l e p o r t i o n s . A f t e r September 1 , 1984, no EDB r e s i d u e s w i l l be allowed on t h e s e products--domestic o r imported .