NTSB Safety Recommendation Letter P-77-013 through P-77-014

Page 1Official PDF/' . < , !'. r r ! I I , , .' ' ' / /.!j lI' NATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. I S S U E D : J u n e 24, 1977 -------________________I________________- Forwarded to: D r . Eula Bingham Assistant Secretary f o r Occupational Safety and Health Department of Labor 200 Constitution Avenue, NW. Washington, D . C . 20210 i SAFETY RECOMMENDAT I ON (S) P-77-13 and P-77-14 A t 2:42 a.m. e.s.t. on March 26, 1977, t h e Buffalo Police Department reported gas odors i n a telephone company manhole near 1446 South Park Avenue. A National Fuel Gas Company serviceman a r r i v e d a t t h e scene a t 3:14 a.m. and checked t h e v a u l t below the manhole f o r gas. H i s com- b u s t i b l e gas i n d i c a t o r (CGI) indicated a f u l l - s c a l e reading on its s i n g l e , lower-explosive l i m i t s c a l e , and he radioed f o r a d d i t i o n a l help. A t 4:30 a.m. a three-man, emergency r e p a i r crew arrived and removed t h e manhole cover t o vent t h e gas from t h e v a u l t . The r e p a i r crew was composed of supervisory personnel because regular gas company employees were on s t r i k e . The crew foreman walked down t h e street t o determine t h e location of t h e gas main by examining paving patches over previous r e p a i r s , while t h e o t h e r two men remained a t t h e manhole. A s h o r t t i m e l a t e r , t h e foreman heard one of t h e men c a l l f o r help. The foreman found one man on a ladder I n t h e manhole holding t h e other man, who was unconscious. The man on t h e ladder then l.ost consciousness and both f e l l back i n t o t h e manhole. The foreman radioed f o r an ambulance and t h e f i r e department t o help g e t the asphyxiated men o u t of t h e v a u l t . A t 5:OO a.m., firemen, wearing oxygen masks, removed t h e bodies from t h e manhole. The repairmen had not used t h e r e s p i r a t o r y devices which were on the gas company truck. The National Fuel Gas Company's maintenance and operations manual s p e c i f i e d t h a t : (a) No one s h a l l be permitted t o enter a v a u l t o r manhole unless a test has been made f o r t h e presence of gas and f o r oxygen deficiency. 2107 I#

Page 2- 2 - (b) Workmen entering a v a u l t containing gas concentrations o r oxygen d e f i c i e n c i e s s h a l l use an approved r e s p i r a t o r y device and have a l i f e l i n e attached t o t h e i r body. The autopsies on t h e repairmen revealed t h a t t h e cause of death w a asphyxia due t o carbon monoxide (CO) inhalation. Five thousand t o 10,000 p a r t s per m i l l i o n (ppm)(O.5 t o 1.0%) of CO i n air can cause death i n 2 t o 15 minutes. 1/ A sample of t h e coke-oven gas taken the day a f t e r t h e accident was analyzed and was found t o contain approximately 7 percent carbon monoxide. The day a f t e r t h e accident, a 12-inch-diameter, bare steel gas main, which transported manufactured (coke-oven) gas under the street, w a s excavated. A l e a k w a s found i n t h e pipe 200 f e e t away from t h e manhole. The coupling components including many of t h e b o l t s used t o j o i n t h e pipe lengths had rusted; t h i s gas main w a s not protected cathodically i n accordance with 49 CFR 192.457. G a s , escaping a t 10 p s i g pressure, had entered t h e telephone conduit through a j o i n t i n t h e clay telephone duct located 6 inches from t h e gas main. Gas had traveled through t h i s conduit and i n t o t h e manhole and v a u l t . A mobile flame i o n i z a t i o n l e a k survey had been conducted over t h e gas main 2 days before t h e accident, but no i n d i c a t i o n of leaking gas had been detected. The Occupational Safety and Health Administration (OSHA) of t h e Department of Labor has standards f o r t e s t i n g f o r the presence of combustible gases and f o r oxygen deficiency i n v a u l t s and manholes operated by t h e telecommunication and power i n d u s t r i e s but n o t f o r v a u l t s and manholes operated by t h e gas industry. Carbon monoxide an methane, two of t h e main c o n s t i t u e n t s of coke-oven gas, are not l i s t e d under t h e hazardous m a t e r i a l s s e c t i o n of t h e OSHA standards. Therefore, t h e National Transportation Safety Board recommends t h a t t h e Occupational Safety and Health Administration of t h e Department of Labor: Amend its regulations f o r t e s t i n g of atmospheres t o include a l l underground v a u l t s and manholes and t o include s a f e t y standards f o r workers from other i n d u s t r i e s t h a t may have occasion t o e n t e r t h e s e p o t e n t i a l l y dangerous a r e a s . (Class 111, Longer Term Followup) (P-77-13) - - 11 Encyclopedia of Chemical Technology, second edition, 1972.#

Page 3- 3 - Amend its regulations t o include a l l possible t o x i c substances or hazardous materials t h a t might reasonably be found i n v a u l t s and manholes and t o r e q u i r e t h a t persons entering these a r e a s be provided with appropriate devices t o test t h e atmosphere before e n t e r i n g t o insure t h e i r s a f e t y . (Class 111, Longer T e r m Followup) (P-77-14) TODD, Chairman, BAILEY, Vice Chairman, McADAMS and HOGUF,, Members, concurred i n t h e above recommendations. HALEY, Member, did not p a r t i c i p a t e . By: Webster Li4?9Al+ B. Todd, Jr. Chairman#