Chemical Process Hazard Review - American Chemical Society


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2 Process Hazard Review in a Chemical Research Environment MARY J. HOFMANN Experimental Station, Ε. I. du Pont de Nemours and Company, Wilmington, DE 19898

The objectives of the Process Hazards Review program at the Du Pont Experimental Station are reviewed. The scope, organization, format, review method, final report, and frequency are discussed as they apply to research projects. The concept of t a i l o r i n g the review method to the degree of hazard involved i s explained and an example of a Process Hazards Review and a Pre-Startup Review/Process Hazards Audit are given. I t h a s l o n g been r e c o g n i z e d t h a t a c c i d e n t s r a r e l y r e s u l t from unforeseeable hazards. They a l s o r a r e l y come about from " a c t s o f God". What we have come t o r e a l i z e i s t h a t a c c i d e n t s r e a l l y r e s u l t from a f a i l u r e t o d e f i n e and c o n t r o l known h a z a r d s t h a t e x i s t due to t h e equipment, t h e c h e m i c a l s , t h e c h e m i s t r y , o r t h e people involved. In t h e Du P o n t Company a s a w h o l e , a v i g o r o u s p r o g r a m o f process h a z a r d s management, o f which Process Hazards Reviews (PHR's) a r e b u t one element, was i n s t i t u t e d and has been recommended by our Corporate S a f e t y & F i r e P r o t e c t i o n D i v i s i o n a s f a r back as 1966 ( 1 ) . The program, o f c o u r s e , has been w i d e l y used a t m a n u f a c t u r i n g s i t e s , but i t s r i g o r o u s a p p l i c a t i o n t o t h e r e s e a r c h environment i n DuPont has been f a i r l y r e c e n t - s i n c e 1979 (3) > I n a number o f ways, i t i s s t i l l e v o l v i n g ; s u c h a s how o f t e n s h o u l d a PHR be h e l d or when i s one needed? R e s e a r c h a t t h e Du Pont Company's E x p e r i m e n t a l Station encompasses v i r t u a l l y a l l f i e l d s o f s c i e n c e - p h y s i c s , c h e m i s t r y , b i o c h e m i s t r y , and e n g i n e e r i n g . The scope o f e x p e r i m e n t a t i o n w i l l range from t h e m i c r o - l e v e l , t o t h e semi w o r k s - l e v e l , u s i n g from m i l l i l i t e r q u a n t i t i e s t o a drum l o t d a i l y . The f r e q u e n c y o f e x p e r i m e n t a t i o n may r a n g e f r o m a o n e - t i m e r u n i n a hood t o a r o u n d - t h e - c l o c k o p e r a t i o n i n a b a r r i c a d e . A P r o c e s s Hazards Review program must encompass a l l t h e s e p o s s i b i l i t i e s .

0097-6156/85/0274-0007S06.00/0 © 1985 American Chemical Society

In Chemical Process Hazard Review; Hoffmann, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

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C H E M I C A L PROCESS H A Z A R D REVIEW

Objectives The u l t i m a t e o b j e c t i v e s o f t h e Du Pont Company's P r o c e s s Hazards Reviews, and P r e - S t a r t u p Reviews/Process Hazards A u d i t s , a r e t o : • e l i m i n a t e i n j u r i e s , and • minimize p r o p e r t y and e n v i r o n m e n t a l damage r e s u l t i n g process hazards.

from

the

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T h i s i s done by: • I d e n t i f y i n g p r o c e s s and equipment hazards which c o u l d cause serious injuries, explosions, fires, or toxic material releases. These hazards may have been p r e v i o u s l y u n r e c o g n i z e d ; o r t h e y may have been r e c o g n i z e d and t o l e r a t e d but avoided by s k i l l e d o r e x p e r i e n c e d employees. • E v a l u a t i n g t h e s i z e o r impact o f t h e h a z a r d s , t h e p o t e n t i a l f o r i n j u r y t o p e r s o n n e l and p r o p e r t y l o s s , and t h e f r e q u e n c y o f occurrence, •

D e v e l o p i n g recommendations t o e l i m i n a t e o r c o n t r o l t h e h a z a r d s ,

and •

Implementing

t h e recommendations.

Definitions The terms P r o c e s s Hazards Review and P r e - S t a r t u p Hazards A u d i t have been mentioned and a r e d e f i n e d .

Review/Process

P r o c e s s Hazards Reviews comprise f o r m a l committee meetings where hours are spent i n t e n s i v e l y e x a m i n i n g , by one o f t h e methods described l a t e r , a chemical r e a c t i o n or process, w i t h a report, documentation, and f o l l o w - u p . P r e - S t a r t u p Reviews/Process Hazards A u d i t s a r e no l e s s i n t e n s i v e , b u t the time spent i s l e s s , because t h e c o m p l e x i t y o f the p r o c e s s o r equipment b e i n g examined i s l e s s . R e p o r t s , d o c u m e n t a t i o n , and f o l l o w - u p a r e a l s o a p a r t o f t h e P r e - S t a r t u p Review/Process Hazards A u d i t . An equipment a c c e p t a n c e s a f e t y i n s p e c t i o n would be c o n s i d e r e d a P r o c e s s Hazards A u d i t . Scope It i s necessary t o have an intensive and yet systematic e x a m i n a t i o n o f t h e p r o c e s s o r t h e equipment f o r hazardous exposures t o p e r s o n n e l and t o p r o p e r t y . T h i s s h o u l d be h e l d from both a t h e o r e t i c a l and a p r a c t i c a l view. "What i f ? " s i t u a t i o n s o r t h o s e not r e a d i l y apparent, such as i m p u r i t i e s i n r e a c t a n t s , t h e m a t e r i a l s o f c o n s t r u c t i o n , or the s u i t a b i l i t y of c o n t r o l d e v i c e s need t o be emphasized. We have made P r o c e s s Hazards Reviews and A u d i t s d i s t i n c t from i n c i d e n t or accident i n v e s t i g a t i o n s , although e i t h e r of these

In Chemical Process Hazard Review; Hoffmann, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

2.

HOFMANN

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Hazard Review in a Chemical Research Environment

may b r i n g home the need t o h o l d one, or survey.

a s may an a r e a s a f e t y a u d i t

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An e x a m p l e where t h e r e was a need f o r a P r o c e s s H a z a r d s Review o c c u r r e d r e c e n t l y i n i n v e s t i g a t i n g an i n c i d e n t i n which t h e r e was a s m a l l e x p l o s i o n i n an oxygen supply c o n n e c t i o n t o a high pressure r e a c t o r . During the i n v e s t i g a t i o n , i t was brought o u t t h a t the oxygen supply system was i n s t a l l e d a f t e r t h e o r i g i n a l P r o c e s s Hazards Review was h e l d , and t h a t t h i s new oxygen system had never been i n t e n s i v e l y r e v i e w e d . Review Needed The most d i f f i c u l t d e c i s i o n i n t h e r e s e a r c h environment i s when t o conduct a P r o c e s s Hazards Review. A PHR c e r t a i n l y need n o t be h e l d f o r a l a b o r a t o r y - s c a l e experiment conducted i n a c h e m i c a l fume hood f o l l o w i n g a documented procedure - t h i s i s t h e one end o f the spectrum. A t t h e o t h e r end, a PHR m u s t be h e l d on a s e m i w o r k s o p e r a t i o n , t h a t w i l l be r u n n i n g a r o u n d t h e c l o c k , i n v o l v i n g drum q u a n t i t i e s o f m a t e r i a l s . I t i s i n the scale i n between t h a t a d e c i s i o n i s more d i f f i c u l t . The Du Pont E x p e r i m e n t a l S t a t i o n has s e t up c e r t a i n g u i d e l i n e s . PHR s must be held on: 1

φ A l l new c a p i t a l p r o j e c t s when s p e c i f i e d i n t h e p r o j e c t write-up. These c a p i t a l projects could cover, f o r example, the purchase and i n s t a l l a t i o n o f a piece of analytical e q u i p m e n t s u c h a s an e l e c t r o n m i c r o s c o p e , o r t h e r e n o v a t i o n and e q u i p p i n g o f a new polymer t e s t i n g l a b o r a t o r y . • A l | C l a s s IV l a s e r s . These a r e high power l a s e r s h a v i n g 5 X 10" w a t t s o f power o r g r e a t e r . PHR s are r e q u i r e d because o f the c o n t r o l measures, such as i n t e r l o c k s and s i g n s ; and t h e h e a l t h h a z a r d s t h a t e x i s t when t h e s e l a s e r s are i n use. 1

P r o c e s s Hazards cases: •

Reviews

New o r r e v i s e d o p e r a t i o n s

are strongly

Laboratory -

i n these

i n a semiworks a r e a ,

• Laboratory reactions t h a t may because o f the r e a c t a n t s o r p r o d u c t s , •

recommended

be

potentially

r e a c t i o n s using chemicals that

explosive

are:

highly toxic radioactive carcinogenic

• L a b o r a t o r y o p e r a t i o n s on a l a r g e s c a l e such as t h o s e u s i n g 22-liter flasks f o r reactions, isolations, purifications, etc.,

In Chemical Process Hazard Review; Hoffmann, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

C H E M I C A L PROCESS H A Z A R D REVIEW

10

• L a b o r a t o r y r e a c t i o n s t h a t w i l l be r u n n i n g around o r f o r more than t h e normal e i g h t - h o u r work day, and • Laboratory operations w i l l be under p r e s s u r e .

where

standard

glassware

the

or

clock

plastic

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These g u i d e l i n e s a r e not meant t o be a l l i n c l u s i v e and t h e r e a r e cases where a c o m b i n a t i o n o f l e s s hazardous c o n d i t i o n s can c r e a t e a need f o r a P r o c e s s H a z a r d s R e v i e w o r a P r e - S t a r t u p Review/Process Hazards A u d i t . Types o f Reviews The next d e c i s i o n t o be made a f t e r the need f o r a PHR has been e s t a b l i s h e d i s what t y p e o f r e v i e w t o h o l d . A l o o k a t the v a r i o u s t y p e s and a d e s c r i p t i o n o f each w i l l be h e l p f u l . •

"What i f ? "

The "What i f ? " i s d e s i g n e d f o r r e l a t i v e l y uncomplicated processes. At each s t e p i n t h e p r o c e s s o r r e a c t i o n "What i f ? " q u e s t i o n s a r e asked and the answers a r e c o n s i d e r e d i n e v a l u a t i n g t h e e f f e c t s o f f a i l u r e s o f components o r e r r o r s i n the procedure (2). •

Checklist

F o r s l i g h t l y more complex p r o c e s s e s , the c h e c k l i s t method p r o v i d e s a more o r g a n i z e d approach (2). T h i s i s accomplished by t h e use o f l i s t s o f words o r phrases t h a t w i l l s t i m u l a t e q u e s t i o n s concerning the s u b j e c t . For example, t h e phrase Personnel P r o t e c t i o n s h o u l d l e a d t o q u e s t i o n s r e l a t i n g t o t h e adequacy o f v e n t i l a t i o n and t o x i c i t y o f t h e c h e m i c a l s u s e d . There are a number o f c h e c k l i s t s a v a i l a b l e i n Du Pont, each a p p l i c a b l e t o the s i t e o r d e p a r t m e n t f o r w h i c h i t was w r i t t e n . Assignments of c e r t a i n a s p e c t s o f t h e p r o j e c t under review can be made t o committee members who have t h e g r e a t e s t e x p e r t i s e i n t h a t a r e a . •

F a i l u r e Mode and E f f e c t A n a l y s i s (FM&E)

When a n a l y s i s i s needed o f a s m a l l p o r t i o n o f a l a r g e p r o c e s s o r o f an i t e m o f equipment, such as a r e a c t o r , t h e F a i l u r e Mode and E f f e c t method can be u s e d (2±. W h i l e t h i s method may not evaluate operating procedure e r r o r s or omissions, or the p o s s i b i l i t y o r p r o b a b i l i t y o f o p e r a t o r e r r o r , i t does a s s e s s t h e consequences o f component f a i l u r e s on t h e p r o c e s s . T h i s type o f a n a l y s i s has been used i n f r e q u e n t l y a t t h e E x p e r i m e n t a l S t a t i o n , and then most o f t e n i n a somewhat m o d i f i e d form. •

Hazard and O p e r a b i l i t y (HAZOP) Study In

t h i s method, e v e r y p a r t o f a p r o c e s s i s examined t o

In Chemical Process Hazard Review; Hoffmann, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

2.

HOFMANN

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d i s c o v e r how d e v i a t i o n s from t h e i n t e n d e d d e s i g n can occur and how t h e s e d e v i a t i o n s can cause h a z a r d s . No HAZOP s t u d i e s have been performed a t t h e E x p e r i m e n t a l S t a t i o n because t h e o t h e r methods have s e r v e d our o p e r a t i o n s s u c c e s s f u l l y .

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F a u l t Tree A n a l y s i s (FTA)

F i n a l l y t h e most r i g o r o u s method i s t h e F a u l t Tree A n a l y s i s . In t h i s method, a s p e c i f i c u n d e s i r e d p r o c e s s event such as an e x p l o s i o n i s p o s t u l a t e d and p l a c e d a t t h e t o p o f a t r e e , from which branches r e p r e s e n t i n g a l l p o s s i b l e precursor events o r causes a r e extended. When b a s i c causes a r e r e a c h e d , f a i l u r e r a t e s are e s t i m a t e d o r o b t a i n e d . While much has been w r i t t e n about F a u l t Tree A n a l y s i s , t h i s method has n o t been used a t our r e s e a r c h s i t e because l e s s r i g o r o u s methods a r e more s u i t e d t o our r a p i d l y c h a n g i n g r e s e a r c h environment. I t has been e x t e n s i v e l y used a t our p r o d u c t i o n s i t e s , however. S e l e c t i o n o f Type o f Review The t h i n k i n g and d e c i s i o n making used a t t h e E x p e r i m e n t a l S t a t i o n a r e based on t h e i n f o r m a t i o n i n Table I . In t h i s t a b l e , an e v a l u a t i o n o f t h e c o m p l e x i t y o f t h e p r o c e s s as i t r e l a t e s t o t h e s c a l e o f t h e o p e r a t i o n i s made. Then a PHR method i s s e l e c t e d , u s i n g i n a s c e n d i n g o r d e r o f i n t e n s i t y , t h e "What i f ? " , the C h e c k l i s t , t h e F a i l u r e Mode & E f f e c t , and t h e F a u l t Tree.

TABLE I . PHR SELECTION METHOD

Scale

Batch Process Lab/SW Service

Continuous Lab/SW

Process Service

E x p l o r a t o r y Research Research Scale-up ( l b s . )

What i f ? What i f ? Checklist

What i f ? What i f ? Checklist

What i f ? What i f ? Checklist

What i f ? Checklist FM&E

P r o c e s s Development Start-up/Shu tdown

FM&E

FM&E

FM&E

Freestanding Purchased Equipment

What i f ? o r

Checklist

What i f ? Checkl i s t j ~ FM&E FTA

FTA

What i f ? o r C h e c k l i s t

Level o f PHR method

As can be seen, i n b a t c h o p e r a t i o n s , t h e "What i f ? " method i s most commonly used, w i t h t h e C h e c k l i s t and F a i l u r e Mode & E f f e c t

In Chemical Process Hazard Review; Hoffmann, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

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method used i n l a r g e r , more complex o p e r a t i o n s . The E x p e r i m e n t a l S t a t i o n S e r v i c e o r g a n i z a t i o n , u s i n g i t s own p e r s o n n e l , c a r r i e s out v a r i o u s e x p e r i m e n t s f o r r e s e a r c h e r s ; and a t the b a t c h l e v e l , cond u c t s e s s e n t i a l l y t h e same t y p e o f PHR as a l a b o r a t o r y o r semiworks does. F a l l i n g somewhat o u t s i d e o f t h e s c a l e concept i s the category of f r e e s t a n d i n g purchased equipment, such as i n s t r u m e n t s , where a "What i f ? " o r Checklist analysis is conducted. In a c o n t i n u o u s o p e r a t i o n t h e "What i f ? " o r C h e c k l i s t method w i l l a l s o be conducted t o a g r e a t e x t e n t , but a F a i l u r e Mode & E f f e c t a n a l y s i s would be used i n a c o n t i n u o u s process w i t h s t a r t - u p s and shutdowns. Process Hazards Review Committee A f t e r the r e v i e w method i s chosen, t h e r e s p o n s i b i l i t y f o r h o l d i n g t h e PHR o r P r e - S t a r t u p Review f a l l s t o th e l i n e o r g a n i z a t i o n who c o n t a c t t h e P r o c e s s Hazards Review Committee. At t h e E x p e r i m e n t a l S t a t i o n , each r e s i d e n t L a b o r a t o r y o r Department has a committee a p p r o p r i a t e t o i t s needs. In each c a s e , t h e committee chairman i s i n a management p o s i t i o n and can command t h e r e s o u r c e s n e c e s s a r y to r e v i e w the p r o c e s s or equipment s u c c e s s f u l l y . I t i s the chairman's r e s p o n s i b i l i t y t o a s s u r e t h a t t h e r e v i e w i s i n t e n s i v e and c o v e r s a l l a s p e c t s o f t h e p r o c e s s o r equipment. The chairman a l s o s e r v e s as t h e L a b o r a t o r y ' s l i a i s o n w i t h t h e S i t e P r o c e s s Hazards Management Committee. The committee i t s e l f c o n s i s t s o f , as w e l l as the chairman, t h e d e s i g n e r o r u s e r o f t h e p r o c e s s o r equipment, who a r r a n g e s t h e meeting time and p l a c e and p r e p a r e s the n e c e s s a r y documents. The d e s i g n e r o r u s e r a l s o a c t s as t h e s e c r e t a r y f o r t h e r e v i e w . O t h e r s on t h e committee i n c l u d e : • The S a f e t y Engineer from the S i t e S a f e t y O f f i c e with l i a i s o n r e s p o n s i b i l i t y f o r t h e r e s i d e n t L a b o r a t o r y i n which t h e p r o c e s s o r equipment i s l o c a t e d , • A technical equipment,

person

not

connected

with



A d e s i g n e n g i n e e r , i f one was



An e n g i n e e r i n g maintenance s u p e r v i s o r .

the

process

or

involved,

T h i s group forms the n u c l e u s and i s c o n s i d e r e d a minimum. O t h e r s w i t h s p e c i a l s k i l l s may need t o be i n v o l v e d f o r some reviews, such as t h e Site Industrial H y g i e n i s t , the Site R a d i o l o g i c a l S a f e t y O f f i c e r , an i n s t r u m e n t a t i o n e n g i n e e r , o r a person experienced w i t h e x p l o s i o n hazards. Process Hazards Review Agenda A t y p i c a l agenda f o r a P r o c e s s Hazards these l i n e s :

Review g e n e r a l l y

follows

In Chemical Process Hazard Review; Hoffmann, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

2.

HOFMANN

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• P r e f e r a b l y , a t l e a s t a week p r i o r t o t h e s c h e d u l e d t i m e , t h e u s e r o f t h e p r o c e s s o r equipment sends t o each committee member f o r r e v i e w , a document c o n t a i n i n g :

-

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Hazard Review in a Chemical Research Environment

meeting

A g e n e r a l statement about t h e purpose o f t h e p r o c e s s o r equipment; The p r o c e s s c h e m i s t r y , such as r e a c t i o n r a t e s , c o o l i n g r a t e s , s i d e r e a c t i o n s , t e m p e r a t u r e s , and p r e s s u r e ; The p r o c e s s m a t e r i a l o r e q u i p m e n t h a z a r d s , s u c h a s toxicity, f l anmability, electrical, and m e c h a n i c a l hazards; The l o c a t i o n o f s a f e t y equipment; The procedure f o r emergency shutdown; The p r o c e s s f l o w diagram; A d e s c r i p t i o n o f t h e equipment, i n c l u d i n g , f o r example, pressure and temperature ratings and controls, construction, capacity, the r e l i e f d e v i c e s , and instrumentation; The operating instructions, including the safety p r e c a u t i o n s t o be t a k e n and p r o t e c t i v e c l o t h i n g t o be worn a t each s t e p o r s e r i e s o f s t e p s ; The w a s t e d i s p o s a l a n d s p i l l c o n t r o l p r o c e d u r e s a n d o t h e r e n v i r o n m e n t a l c o n s i d e r a t i o n s ; and An appendix c o n t a i n i n g m a t e r i a l s a f e t y d a t a s h e e t s on t h e c h e m i c a l s used i n t h e p r o c e s s o r equipment and any other information o f a h e l p f u l nature.

• At t h e s c h e d u l e d m e e t i n g , t h e complete package o f i n f o r m a t i o n i s r e v i e w e d a n d d i s c u s s e d . T h i s i s t h e t i m e t h e "What i f ? " q u e s t i o n s a r e a s k e d , o r t h e C h e c k l i s t used. I f a F a i l u r e Mode & E f f e c t a n a l y s i s i s u s e d , t h i s i n f o r m a t i o n a l s o w i l l have been p r o v i d e d and d i s c u s s e d . • F o l l o w i n g t h e d i s c u s s i o n , t h e committee makes a f i e l d a u d i t , c h e c k i n g t h e s u i t a b i l i t y and placement o f equipment, t h e impact o f t h e p r o c e s s on t h e a r e a , and t h e impact o f t h e a r e a on t h e process. On complex p r o c e s s e s , t h e o p e r a t i o n i s g e n e r a l l y s u b d i v i d e d i n t o l o g i c a l o r manageable u n i t s and s e p a r a t e PHR s a r e conducted on each u n i t . 1

In almost a l l c a s e s , t h e person r e s p o n s i b l e f o r t h e p r o c e s s o r equipment b e i n g r e v i e w e d writes the f i n a l r e p o r t which i n c l u d es: •

The hazards i d e n t i f i e d , whether e x i s t i n g o r p o t e n t i a l ,



The committee's

recommendations f o r c o r r e c t i v e a c t i o n s ,

• The p e r s o n s responsible f o r the corrective a c t i o n s and d a t e s f o r c o m p l e t i o n , a c t i o n s and d a t e s f o r c o m p l e t i o n , and

In Chemical Process Hazard Review; Hoffmann, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

14

C H E M I C A L PROCESS H A Z A R D REVIEW

• A summary o f a l l q u e s t i o n s r a i s e d and r e s o l v e d f u t u r e PHR*s on t h e same p r o c e s s w i l l n o t "plow t h e same again" .

so t h a t ground

T h i s w r i t t e n f i n a l r e p o r t i s then sent t o a l l committee members, a p p r o p r i a t e members o f management, and g e n e r a l l y t o t h e central file o f t h e r e s e a r c h l a b o r a t o r y i n which t h e PHR or i g i n a t e d .

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Process Hazards Review

Frequency

We recommend t h a t r e - r e v i e w s be h e l d whenever a s u b s t a n t i a l change i s made i n e x i s t i n g o p e r a t i o n s . Changes s u c h a s i n c r e a s e d p r e s s u r e s and/or t e m p e r a t u r e s , o r d i f f e r e n t r e a c t a n t s s i g n a l t h e need f o r a r e - r e v i e w . Changes t o f i x e d equipment s h o u l d a l s o be e v a l u a t e d , and a d e c i s i o n made a s t o w h e t h e r a r e - r e v i e w i s necessary. Examples The f i r s t example i s o f a P r o c e s s Hazards Review conducted on a flow r e a c t o r designed t o t e s t the a c t i v i t y o f heterogeneous c a t a l y s t s i n t h e r e a c t i o n o f m i x t u r e s o f hydrogen, carbon monoxide, and/or carbon dioxide. T h i s r e a c t o r system had p r e v i o u s l y been r e v i e w e d and t h e Review t h i s time was t o a s s e s s the h a z a r d s o f t h e a d d i t i o n o f a v a p o r i z e r and l i q u i d pump t o t h e system. A committee was assembled • • • • • •

and c o n s i s t e d o f :

t h e Department P r o c e s s Hazards Review Chairman, t h e d e s i g n e r and u s e r o f t h e system, the user's supervisor, the Safety Engineer responsible f o r Process Hazards Reviews, t h e a r e a e n g i n e e r i n g s u p e r v i s o r , and two e x p e r t s i n t h e f i e l d s o f h i g h p r e s s u r e and b a r r i c a d e s .

The committee convened i n a c o n f e r e n c e room and reviewed a l l t h e m a t e r i a l w h i c h h a d p r e v i o u s l y b e e n s e n t t o them. This i n c l u d e d a l l t h e i n f o r m a t i o n p r e v i o u s l y recommended i n t h i s paper i n t h e f i r s t p a r t o f t h e P r o c e s s Hazards Review Agenda s e c t i o n a s w e l l as e n v i r o n m e n t a l a i r e m i s s i o n s d a t a and gas chromatograph procedures. The committee reviewed t h e m a t e r i a l and then i n s p e c t e d t h e system. The n e x t d a y , t h e chemist i s s u e d t h e minutes o f t h e PHR on h i s f l o w r e a c t o r . These were s e n t t o each o f t h e p a r t i c i p a n t s and i n c l u d e d t h e d e t a i l s o f t h e time and p l a c e o f t h e meeting; a b r i e f r e v i e w o f t h e p u r p o s e o f t h e PHR, n a m e l y t o r e v i e w t h e m o d i f i c a t i o n s ; and t h e four recommendations t h a t a r o s e from t h e r e v i e w . M i n u t e s such a s t h e s e i n s u r e t h a t a l l members o f

In Chemical Process Hazard Review; Hoffmann, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

2.

HOFMANN

Hazard Review in a Chemical Research Environment

the committee a r e i n agreement, tions.

especially

with

15

t h e recommenda-

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T h i s r e v i e w was t h e n complete and t h e documents were s e n t t o a central f i l e . The next example i s o f a P r e - S t a r t u p Review o r a P r o c e s s Hazards A u d i t h e l d on a p i e c e o f purchased p r o c e s s i n g equipment, a Haake Rheocord Torque Rheometer and L a b o r a t o r y Twin-screw Extruder. The o r g a n i z a t i o n r e s p o n s i b l e f o r t h i s e x t r u d e r has a s t a n d a r d c h e c k l i s t o f e l e v e n pages o f i t e m s t o be c o n s i d e r e d by the t e c h n i c a l person o r persons i n charge o f t h e equipment o r process, before the review i sheld. Copies o f t h e completed c h e c k l i s t a r e t h e n s e n t t o e a c h c o m m i t t e e member b e f o r e t h e meeting f o r r e v i e w . G e n e r a l l y , i n a review o f t h i s type, t h e group w i l l convene a t t h e l o c a t i o n o f t h e equipment r a t h e r than i n a c o n f e r e n c e room t o go o v e r t h e m a t e r i a l p r o v i d e d . I n t h i s c a s e , the committee c o n s i s t e d o f : • • • • •

the three t e c h n i c a l personnel responsible, t h e s a f e t y c o o r d i n a t o r s f o r t h e Department, one o f whom was the P r o c e s s Hazards Chairman, t h e S i t e a r e a e n g i n e e r i n g maintenance s u p e r v i s o r , t h e S i t e S a f e t y Engineer w i t h l i a i s o n r e s p o n s i b i l i t y f o r t h e Department, and t h e P r o c e s s Area S u p e r v i s o r .

A complete d i s c u s s i o n o f a l l t h e c h e c k l i s t i t e m s i n t h i s P r e - S t a r t u p R e v i e w would n o t be p o s s i b l e i n t h i s p a p e r b u t c o n s i d e r a t i o n was g i v e n t o a l l o f them. As a r e s u l t , a memorandum was i s s u e d by t h e t e c h n i c a l p e r s o n n e l t o t h e committee o u t l i n i n g the recommendations made. These recommendations covered f i v e a r e a s and t o t a l l e d 17 i n a l l . Ihe recommendations i n c l u d e d t h e n e e d f o r a s p l a s h p a n on t h e w a t e r t a n k , some g u a r d s o n t h e pelletizer and rheometer drive, correct color c o d i n g and i d e n t i f i c a t i o n o f v a l v e s , and t h e need f o r an eye wash and s a f e t y shower t o be i n s t a l l e d nearby. T h i s P r e - S t a r t u p Review took about one hour o f committee time and t h e equipment was n o t o p e r a t e d u n t i l t h e recommendations were completed and t h e r e v i e w approved. Conclusion W h i l e t h i s whole r e v i e w system t h a t has been d e s c r i b e d may sound l i k e an overwhelming and t i m e consuming t a s k , t h e Du Pont E x p e r i m e n t a l S t a t i o n i s c o n v i n c e d t h a t P r o c e s s Hazards Reviews and Audits are worthwhile and are conducting more of them every year.

Literature Cited 1. Du Pont Safety and Fire Protection Guidelines, Section 6.1, "Process Hazards Management", Feb., 1979. 2. Du Pont Safety and Fire Protection Guidelines, Section 6.4, "Process Hazards Reviews", July, 1981. 3. Du Pont Experimental Station Safety and Fire Protection Guide, Procedure 111, "Process Hazards Review (PHR)", 1/25/82. RECEIVED November 3, 1984 In Chemical Process Hazard Review; Hoffmann, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1985.