# DISCLAIMER
Mention of company names or products does not co n stitu te endorsement by the National In s titu te for Occupational Safety and Health.

# D H H S (N IO S H ) Publication No. 81-131

# PREFACE
The Occupational Safety and Health Act of 1970 emphasizes the need to p ro tect the h ealth and safety of workers occupationally exposed to an everincreasing number of p o te n tia l hazards. Consequently, the N ational I n s titu te fo r Occupational Safety and H ealth (NIOSH) has implemented a program to evaluate the adverse h ealth e ffe c ts of chemical and physical agents and in d u stria l processes. This summary of NIOSH's Occupational Hazard Assessment of Coal L iquefaction is a re s u lt of th at program. By addressing the hazard while d ire c t coal liq u e fa c tio n technology is s t i l l being developed, the ris k of p o te n tia l adverse h ealth e ffe c ts can be su b sta n tia lly reduced in both experim ental and commercial p la n ts.
While the occupational hazard assessm ent, Volume I I , is a c r i t ic a l, lengthy review of the s c ie n tific and technical inform ation a v ailab le and discusses the occupational safety and health issues of p ilo t p lan t o p eration s, th is summary document presents the h ig h lig h ts in a sh o rte r, more useable form fo r a wider audience. Both documents are intended for use by w orkers, in dustry , trade a sso c ia tio n s, government agencies, s c ie n tific and tech n ical in v e stig a to rs, and the public; those in te re ste d in a more thorough and d etailed discussion should read the Occupational Hazard Assessment of Coal L iquefaction. The inform ation and recommendations presented should f a c ilita te development of sp e c ific procedures for hazard control in individual workplaces by persons immediately responsible for h ealth and safety . NIOSH w ill p e rio d ica lly update and evaluate new data and inform ation as they become av ailab le and, a t the appropriate tim e, w ill consider proposing recommendations for a standard to protect workers in commercial coal liq u efactio n f a c ilitie s . Ronald F. Coene, P.E. Acting D irector N ational I n s titu te fo r Occupational Safety and Health

# SYNOPSIS
The coal liq u efactio n process converts coal in to hydrocarbon products. In doing so, i t both uses and produces to xican ts p o te n tia lly hazardous to worker h e alth . The to x ican ts are v aried , ranging from simple chem icals to complex m ixtures or organic carcinogens. The possib le h ealth e ffe c ts are also v aried . Animal stu d ies have demonstrated th a t some of the process chemicals have produced tumors a t the s ite of ap p licatio n . Some workers may be exposed by in h alatio n of gases, vapors, or airborne p a rtic le s , skin contact w ith airborne m ateria l, contact w ith contaminated su rfaces, or accid en tal in g estio n . Some of these same chemicals have caused severe long-term e ffe c ts such as skin and lung cancer in workers in sim ilar in d u strie s. Other p o te n tia l adverse h ealth e ffe c ts may include fa ta l poisoning from in h a la tio n , severe re sp ira to ry ir r ita tio n , and chemical burns. F ires and explosions can also occur.
This document is designed to provide inform ation th a t can be used to guard against these p o te n tia l adverse h ealth e ffe c ts. Measures such as engineering co n tro ls, sp e c ific work p ra c tic e s, personal p ro te c tiv e equipment, medical su rv eillan ce and exposure m onitoring, recordkeeping, and emergency plans and procedures are recommended. INTRODUCTION

# INTRODUCTION
Coal liq u e fa c tio n is a process th at converts coal in to hydrocarbon products. Most o ften , the major products are condensed arom atic liq u id s, with some gases and so lid s also produced, pending on operating conditions and the type of coal and process used. L iquefaction is accomplished by breaking the chemical and physical bonds of the coal in the presence of a hydrogen source. The four major coal liq u efactio n processes are: (1) p y ro ly sis, in which the coal is heated in the absence of oxygen, and hydrogen is ab stracted from coal hydrogen donors; (2) solvent e x tractio n , which is performed a t high tem peratures and pressures in the presence of hydrogen and a solvent; (3) d ire c t hydrogenation, in which the coal slu rry is hydrogenated in contact w ith a c a ta ly st under high pressure and tem perature; and (4) in d ire c t liq u e fa c tio n , in which the coal is g asified w ith steam and oxygen and then c a ta ly tic a lly converted to liq u id products. This assessment is concerned w ith d ire c t liq u e fa c tio n , ie , processes 1-3.
In the United S ta te s, coal liq u efactio n technology is only beginning to develop. I t cu rren tly c o n sists of a small number of process development u n its (PDU) fo r e stab lish in g process fe a s ib ility and p ilo t p lan ts. Processing cap a c ities range from le ss than 5 tons per day (4.5 Mg/d) for the PDU's up to 600 tons per day (544 Mg/d) fo r the p ilo t p la n ts. These p ilo t p lan ts are prim arily a te stin g ground for determ ining optimum operating conditions for fu tu re commercial p lan ts. Previous p ro jectio n s based on plans for development of sy n th etic fuel technology show th a t as many as 12 comm ercial-sized liq u efactio n p lan ts may be operating by 1995 (assuming each produces approximately 50,000 b b l/d ). C o llectiv ely , these p lan ts are lik e ly to employ more than 12,000 workers , An increased number of coal miners must also be considered part of the to ta l impact of coal liq u efactio n technology on occupational safety and h e alth .
In addition to evaluating health e ffe c ts , th is summary document recommends engineering co n tro ls, work p ra c tic e s, personal p ro tectiv e equipment and clo th in g , medical su rv eillan ce, and exposure m onitoring to reduce the h ealth risk s and provide fo r increased worker safety in coal liq u efactio n p lan ts. G reater d e ta il is given in the fu ll-le n g th document . NIOSH's recommendations can be used fo r planning occupational safety and h ealth programs and as a basis for technology development.
In the fu ll-le n g th document on coal liq u e fa c tio n , the occupational hazards associated w ith the d ire c t process are thoroughly reviewed. NIOSH has determined th a t chemicals and physical agents id e n tifie d in the process could present serious h ealth and safety hazards to the workers in p ilo t p lants and in future commercial p lants unless precautions are taken.
One serious h ealth hazard associated w ith coal liq u efactio n processes is cancer . C ertain arom atic amines and polycyclic hydrocarbons measured a t two p ilo t p lan ts in v estig ated by NIOSH are known carcinogens or co-carcinogens . In ad d itio n , coal liq u e fa c tio n m aterials applied to the skin of laboratory animals have produced cancerous growths . Coal liq u efactio n m aterials have also caused adverse reproductive e ffe c ts in laboratory animals .
A number of other chemicals found in coal liq u e fa c tio n processes may adversely a ffe c t the re sp ira to ry and nervous systems, as w ell as the blood, liv e r, and kidneys.

# HEALTH EFFECTS
Because coal liq u e fa c tio n is an emerging in d u stry , the opportunity for epidem iologic in v estig atio n has been lim ited to evaluation of worker medical su rv eillan ce programs in p ilo t p lan ts. In 1960 Sexton  suggested th at workers exposed to coal liq u efactio n m aterials have an incidence of cancerous and precancerous skin lesio n s g re ate r than expected in a sim ilar population not occupationally exposed to the same hazard. In sp ite of a number of lim ita tio n s in th is study (including a sm all number of exposed workers, no appropriate comparison population, and a lack of inform ation concerning work h is to rie s , medical h is to rie s , and exposure le v e ls ), the excess incidence of cancerous and precancerous skin lesion s reported would s t i l l be s u ffic ie n t to cause concern. Two other rep o rts  dem onstrate th a t the most common m edical problems a t p ilo t p lan ts have been d e rm a titis, eye ir r ita tio n , and therm al burns. Although there are lim ita tio n s in the epidem iologic data av ailab le on coal liq u e fa c tio n , there are strong im plications from animal toxicologic and human epidem iologic stu d ies on analogous compounds th a t c e rta in agents in the coal liq u efactio n process pose serious h ealth hazards. Such examples include chemical agents found in coal ta r products  and coke oven emissions . Therefore, every possible precautionary measure should be taken to p ro tect the worker.
Processing of abrasive s lu rrie s , p a rtic u la rly a t high tem peratures and p ressures, accelerates erosion and corrosion th at may cause leaks in process equipment. Leaks increase the p o te n tia l fo r worker skin contact with process m ateria ls, in h alatio n exposure, burns, and f ir e s . In gas handling systems, leaks increase the p o s s ib ility of worker exposure to high, and p o te n tia lly f a ta l, lev els of carbon monoxide and hydrogen su lfid e .
Because coal liq u efactio n processes operate above the au to ig n itio n tem perature of many process m ateria ls, leaks could re s u lt in immediate f ire s . Furtherm ore, many process m aterials are explosive, and leaks may re s u lt in a m ixture th a t exceeds i t s lower explosive lim it. This could re s u lt in an explosion.
The follow ing paragraphs describe sp ec ific h ealth e ffe c ts . Some guidance is given on elements of the appropriate physical exam inations and laboratory te s ts . Skin E ffects NIOSH has previously reported on some chemicals th a t are sim ilar to those in coal liq u efactio n processes and th at a ffe c t the skin. For example, creosote has caused k e r a titis , and crude naphtha, creosote, and resid u al pitch have caused skin cancer . These m aterials can also inflam e h a ir f o llic le s and sebaceous glands. Cresol causes a burning sensation, erythema, lo calized anesthesia, and a brown d isco lo ratio n of the skin upon contact . NIOSH has also described skin e ffe c ts as major concerns in workers exposed to carbon black process m aterials , refin ed petroleum solvents , coke oven em issions , and phenol .
Skin se n sitiz a tio n may occur a fte r skin contact w ith or in h alatio n of many d iffe re n t chem icals. Patch te stin g should be used as a diagnostic aid only a fte r a worker has symptoms of skin s e n sitiz a tio n . Patch te s ts must not be used as a preplacement or screening technique, because they may cause se n sitiz a tio n ; medical h isto ry and physical examination are much safer ways of estim ating whether a worker is se n sitiz e d . Skin lesio n s should be m onitored, and w ritten and photographic records of th e ir development should be made and kept. If lesio n s change, the worker should be referred to a derm atologist.
Liver Effects NIOSH has previously concluded th a t exposure to creso l may re s u lt in damage to the liv e r and th a t medical su rv eillan ce w ith emphasis on any preex istin g liv e r disorder should be conducted on workers exposed to cresol . Because of the vast reserve functio nal capacity of the liv e r, acute hep ato to x icity or severe cumulative chronic damage may occur before recognizable symptoms appear. These symptoms include nausea, vom iting, diarrh ea, weakness, general m alaise, and jaundice. Numerous screening te s ts for liv e r dysfunction e x ist; those most frequently used are serum b iliru b in , serum glutam ic-oxaloacetic transam inase (SGOT), serum glutam icpyruvic transam inase (SGPT), gamma glutamyl tran sp ep tid ase (GGTP), and is o c itr ic dehydrogenase.

# Kidney Effects
NIOSH has previously concluded th a t exposure to creso l , carbon d isu lfid e , coke oven em issions , and coal ta r products  can re s u lt in impaired ren al function. Renal function impairment can be screened by u rin a ly sis augmented by more sp ec ific te s ts .

# Respiratory System Effects
Inhalatio n of chemicals in coal liq u e fa c tio n p lan ts may re s u lt in damage to the resp ira to ry system. For example, su lfu r dioxide and ammonia are re sp ira to ry tr a c t ir r ita n ts , and su b sta n tia l exposures to ammonia can produce chronic b ro n c h itis, la ry n g itis , tr a c h e itis , bronchopneumonia, and pulmonary edema . Exposure to su lfu r dioxide can cause asphyxia and severe chemical bronchopneumonia . In h alatio n of coke oven em issions and coal ta r products can lead tc chronic lung disease, including cancer . Inhalatio n and pulmonary deposition of fre e s ilic a can cause s ilic o s is , a form of pulmonary fib ro s is . If a worker does not have symptoms of re sp ira to ry d is tre s s , physical examination alone may not d etect early pulmonary illn e s s . Therefore, a chest X-ray examination is recommended a t the time of employment and th e re a fte r a t the d isc re tio n of the physician. In ad d itio n , pulmonary function te s ts , ie , forced v ita l capacity (FVC) and forced expiratory volume in 1 second (FEV 1), are also recommended screening te s ts . Blood E ffects Because exposure to benzene has been linked w ith leukemia , workers exposed to i t should have a complete blood count (CBC) as a screening te s t fo r blood d iso rd ers. A CBC includes determ ination of hemoglobin (Hb) concentration, hem atocrit, red blood c e ll (RBC) count, re tic u lo c y te count, w hite blood c e ll (WBC) count, and WBC d iffe re n tia l count. C entral Nervous System E ffects Cresol , Medical monitoring is essen tial to protect workers in coal liquefaction plants from adverse health e ffe c ts. To be e ffectiv e, medical surveillance should be both w ell timed and thorough to detect adverse effe c ts on worker health as early as possible. Thoroughness in medical surveillance is necessary because of the many chemical and physical agents a worker may be exposed to. Worker exposure is not predictable; i t can occur whenever any closed process equipment accidentally leaks, vents, or ruptures. Not a ll adverse effects of exposure in coal liquefaction plants are known, but most of the major organs (the liv e r , kidneys , lungs , heart , and skin ) may be affected.
Medical surveillance should consist of preplacement, periodic, and term ination examinations. Preplacement examinations set a baseline for the worker's general health and for sp ecific te s ts , eg, future audiometric te s ts . During these examinations, a worker's physical a b ility to perform h is job while using a resp irato r can be determined. These examinations can also detect some preexisting conditions that may be aggravated by, or make the worker more vulnerable to, the hazards of coal liq u efaction processes. If such a condition is found, the employer should be n o tified and the worker fu lly counseled on these hazards.
Periodic examinations allow monitoring of worker health to assess changes resu ltin g from exposure to m aterials in coal liquefaction processes. Workers should be encouraged to report any change in th e ir health to the medical department; self-exam ination is important to health monitoring. Periodic examinations should be performed at le a st annually. Physical examinations of workers prior to term ination of employment w ill provide complete information to the worker and to the medical surveillance program.
All three types of examinations should be comprehensive and include medical and work h isto rie s , physical examinations, and special te s ts . Medical h isto rie s should focus on preexisting disorders. Work h isto rie s are important because past exposures may predispose the worker to adverse effects; for example, past exposure to coal-derived products may have caused sen sitizatio n .
Physical examinations should be thorough and some c lin ic a l te s ts may be useful as general screening measures. In the screening te s ts , worker acceptance of te s ts should be weighed against the information that the te s t w ill y ield. Physicians should consider the te s t se n sitiv ity , the seriousness of the disorder, and whether the disorder can re su lt from exposure to coal liquefaction m aterials. They should choose te s ts based on th e ir knowledge of exposure-effect relatio n sh ip s, the w orker's exposure conditions, and any preexisting facto rs. If possible, they should choose te s ts w ith simple sample c o lle c tio n , processing, and an aly sis. The physician should ensure th a t appropriate followup te s ts and procedures are carried out if te s t re s u lts are abnormal.

# Exposure M onitoring
In d u stria l hygiene m onitoring is used to determ ine whether worker exposure to chemical and physical hazards is w ithin the lim its se t by OSHA or recommended by NIOSH or other voluntary stan d ard -se ttin g org anization s, and to in d icate where co rrectiv e measures are needed. However, no exposure lim its have been established fo r many substances th at may contam inate the workplace a ir in coal liq u efactio n p lan ts. Exposure m onitoring is necessary where exposure to suspect cancer-causing agents or other toxic m aterials might occur. For these substances, exposure m onitoring is im portant because i t can spot fa ilu re s in engineering con tro ls and work p ra c tic e s, and produce data th at can be used to develop exposure-effect re la tio n sh ip s. I t is not possible now to p red ict a ll of the chemicals in coal liq u efactio n p lan ts th a t may have toxic e ffe c ts . In ad d itio n , the possib le in te ra c tiv e e ffe c ts of individual chemicals should be considered when designing the m onitoring program.
A workplace m aterial survey should be conducted to tab u late workplace m aterials th at may be released in to the atmosphere or may contam inate the skin. G uidelines for sampling and an aly sis may be found in NIOSH's Occupational Exposure Sampling Strategy Manual , the NIOSH Manual of A nalytical Methods , and OSHA's In d u stria l Hygiene F ield Operations Manual . A ll processes and work operations using m aterials known to be toxic or hazardous should be evaluated.
Many m aterials in coal liq u efactio n p lan ts are complex m ixtures of hydrocarbons occurring as vapors, aero so ls, or p a rtic u la te s . Although i t is im practical to measure each component of the m ixture, measuring the cyclohexane-extractable fra c tio n of to ta l p a rtic u la te samples w ill y ield data u seful for evaluating worker exposure. Chemical an aly sis procedures developed fo r coal ta r p itch v o la tile s can be applied to coal liq u efactio n m aterials. However, one must not in fe r th at the perm issible exposure lim it (PEL) of 0.15 mg/cu m for the benzene-soluble fra c tio n of to ta l p a rtic u la te m atter during the carbonization of coal, estab lish ed fo r coke oven em issions, is safe for workers in coal liq u e fa c tio n p la n ts. In stead , m onitoring re s u lts should be in terp reted w ith toxicologic data on sp e c ific , or m ixtures of coal liq u e fa c tio n m aterials.
Alarms should be in sta lle d to monitor substances' or hazards th at could immediately th reaten l i f e and h ealth , such as hydrogen su lfid e , carbon monoxide, oxygen deficiency, and p o te n tia l explosive hazards. NIOSH has published recommendations fo r the use of hydrogen su lfid e alarms , which should be in sta lle d in areas where high concentrations of hydrogen su lfid e may be released . NIOSH also recommends th a t alarms be developed fo r other gases where life -th re a te n in g exposures could occur.

# Recordkeeping
M onitoring worker h ealth and the working environment is e sse n tia l in an occupational h ealth program. Coal liq u efactio n is a developing technology, w ith many hazards s t i l l unknown. Recordkeeping is p a rtic u la rly c r i tic a l to th is technology, where the occupational environment is d if f ic u lt to ch aracterize. S tandardization of the recordkeeping systems is recommended because i t w ill allow easy cross-com parison of data from sim ilar p lan ts and thereby f a c ilita te a more comprehensive examination of the hazards in the industry as a whole . Therefore, coal liq u e fa c tio n p lan ts should have a system th a t records a t le a s t the follow ing inform ation.
(a) Employment H istory For each worker there should be a work h isto ry d e ta ilin g job c la s s ific a tio n s , plant lo catio n codes, and time spent on each job. Compensation claim rep o rts and death c e rtific a te s should be included.
(b) Medical H istory A medical h isto ry comprising personal h ealth h isto ry , medical examination records, and reported illn e ss e s and in ju rie s should be m aintained for each worker.
(c) In d u stria l Hygiene Data Records should be kept of personal and area sampling th at s ta te m onitoring re s u lts , note whether personal p ro te c tiv e equipment was used, and id en tify worker(s) monitored or p lan t lo catio n codes for areas where sampling was performed. Estim ates of the frequency and extent of skin contam ination by coal-derived m aterials should be recorded annually fo r each worker.

# ENGINEERING CONTROLS
Engineering controls of workplace hazards can be applied to both p ilo t and commercial p la n ts. Engineering design for dem onstration coal liq u efactio n p lan ts is cu rren tly in the developmental stag e, and i t should emphasize prevention of worker exposure by ensuring process containm ent, lim itin g worker exposure during m aintenance, and providing for equipment r e lia b ility . The e ffe c ts of erosion, corrosion, and fa ilu re of se a ls, valves, and other process components should be minimized. Design and q u a lity control of pressure v essels should ensure r e lia b ility of vessel in te g rity . Pressure safety and release valves must be designed according to w ell-estab lish ed engineering p ra ctice s and located so th at operating personnel are not exposed to re le a se s. Control rooms should be stru c tu ra lly designed to p ro tect operating personnel and should remain functio nal in an accident. Process sampling equipment should be designed to minimize the relea se of process m ateria l. Many of the engineering design considerations discussed in th is and the fu ll-le n g th document are addressed in ex istin g standards, codes, and reg u latio n s .
A formal system safety program should be in itia te d to provide fo r early recognition of safety problems, an aly sis of design, id e n tific a tio n of p o te n tia l hazards, and sp e c ific a tio n of safety co n tro ls and procedures. At a minimum, the safety program should include:
(1) Scheduled reviews and analyses;
(2) Review re s p o n s ib ilitie s of designated workers;
(3) Required methods of analyses; and (4) Requirements for documentation and c e rtific a tio n . Before equipment is removed or serviced, i t should be iso la te d from the process stream and flushed and purged where p o ssib le. Gas purges should be disposed of by a fla re or some other e ffe c tiv e method. In areas where flammable m aterials are c o llec te d , the flammable gas and vapor concentration must be m aintained a t le ss than i t s lower explosive lim it. If workers enter areas where flammable or toxic m aterials c o lle c t, v e n tila tio n must be adequate to m aintain safe concentrations.
Workers who sample process stream s may be exposed to sig n ific a n t amounts of process m ateria l. During p lan t v i s it s , NIOSH observed workers using a nozzle to d ire c t the m aterial in to sm all cans , a technique th at could lead to excessive and unnecessary exposures. In other p la n ts, NIOSH observed a sa fer method and recommends i t where p ra ctica b le: the use of a closed-loop system designed to remove flammable or toxic m aterial from the sampling lin e s by flushing and purging p rio r to removing the sampling bomb . These flushings from the sampling lin e s should be collected and disposed of properly.
To minimize plugging of lin e s and equipment through coking and s o lid ific a tio n of coal s lu r rie s , instrum entation and co n tro ls should be provided. For example, lin e s and equipment should be h eat-traced to m aintain tem peratures g reater than the pour point of the m ateria l. However, sometimes plugging w ill occur reg ardless of the preventive measures taken. Under these circum stances, lo cal v e n tila tio n and/or re sp ira to rs should be provided and used to lim it exposure to hazardous m aterials during decoking or hydroblasting. Contaminated w ater from hydroblasting should be c o llected , tre a te d , and recycled or disposed of properly. Where p ra ctica b le, equipment used to handle flu id s containing so lid s should be flushed and purged during shutdown to minimize p o te n tia l coal slu rry s o lid ific a tio n or s e ttlin g of so lid s.
Thus, proper engineering design and co n tro ls must include safeguards sp e c ific a lly designed to p ro tect workers. Good engineering design, when combined with safe operating procedures for fu ll-s c a le coal liq u efactio n p lan ts, should provide inherent safeguards. By removing pathways for release of toxic substances to the workplace, the need fo r minimizing exposures to workers w ill be reduced, as w ill relia n ce on personal p ro tectiv e equipment.

# SPECIFIC WORK PRACTICES
There are workplace safety and h ealth programs in coal liq u efactio n p ilo t p lants sim ilar to programs in petroleum re fin e rie s and the chemical in dustry . Most coal liq u efactio n p ilo t p lan ts have w ritten procedures for operational safety p ra c tic e s, including lockout of e le c tric a l equipment, tagout of valves, f ir e and rescue brigades, safe work perm its, v essel entry perm its, wearing of safety glasses and hardhats, and housekeeping.
Developers of occupational safety and h ealth programs should use (1) the general industry standards sp ecified in the Code of Federal Regulations (29 CFR P art 1910), (2) voluntary guidelines from sim ilar in d u strie s, (3) NIOSH recommendations describing sp ec ific work p ra ctice s fo r sim ilar m aterials , (4) recommendations from equipment m anufacturers, and (5) professio nal judgment and operating experience.
For engineering co n tro ls, supplemental work p ra c tic e s, and personal p ro tectiv e equipment to be e ffe c tiv e , employers should ensure th a t workers are informed of the hazards associated w ith the m aterials p resen t, the procedures for handling m aterials and cleaning up s p ills , and the use of personal p ro tectiv e equipment and emergency procedures. Where p o ssib le, o ra l in stru c tio n s should be augmented by w ritten and audiovisual m aterials to ensure th a t workers are always aware of the most current procedures and techniques for ensuring th e ir safety and h e alth . In ad d itio n , worker comprehension of in stru c tio n s should be evaluated.

# Operating Procedures
Procedures are being developed for coal liq u efactio n p ilo t p lan ts for each phase of operation, including sta rtu p , normal operation , routine maintenance, normal shutdown, emergency shutdown, and shutdown fo r extended periods. P rovisions should be made in these procedures for safely sto rin g process m ateria ls, preventing s o lid ific a tio n of dissolved coal, cleaning up s p ills , and decontam inating equipment th at req u ires maintenance. Preventing leaks is a major problem during sta rtu p of high pressure coal liq u efactio n systems; th erefo re , systems should be gradually pressurized and checked for leak s, esp ecially a t valve o u tle ts , b lin d s, and flan ges. Recently rep aired , serviced, or replaced equipment should be c are fu lly examined. I f no leaks are found, the system should be slowly brought up to operating pressure and tem perature. I f leaks occur, appropriate rep airs should be made.
Equipment th at operates at high pressures should be ro u tin ely inspected to determ ine maintenance needs. In te rv a ls should be estab lished for m onitoring and replacing equipment su scep tib le to erosion and corrosion. M onitoring requirem ents, schedules, and replacement in te rv a ls should be p art of a q u ality assurance program.

# Confined Space Entry
NIOSH has made recommendations th at are generally app licable to entry in confined spaces in coal liq u efactio n f a c il iti e s . These recommendations p e rtain to entry perm its, te stin g work atmospheres, m onitoring, medical su rv e illa n c e, personnel tra in in g , lab elin g and postin g, preparations such as is o la tio n , lockout, tagout, purging, and v e n tila tio n , safety equipment and clo th in g , rescue equipment, and recordkeeping. One coal liq u efactio n f a c ility v is ite d by NIOSH recommends an a ir changeover ra te of six times per hour during entry and work in confined spaces.

# R estricted Areas
Access should be controlled a t coal liq u e fa c tio n p lan ts to prevent entry by persons unfam iliar w ith the hazards p resen t, the precautions necessary, and the plant emergency procedures. Access a t one coal liq u efactio n f a c ility is controlled by using warning sig n s, red lig h ts , and b a rrie rs . Because th is f a c ility is sm all, the use of doors as physical b a rrie rs is fe a sib le for access c o n tro l. Fences and gates serve a sim ilar purpose in la rg er operations. Employers should keep a log of workers entering re s tric te d areas to provide a record of who is exposed in high ris k operations. A v is ito r s ' log would aid in accounting fo r people a t the plant in an accident or emergency. V isito rs should be informed of the hazards, necessary precautions, and emergency procedures. S p ill Decontamination S p ills of toxic liq u id s should be cleaned up at the e a r lie s t safe opportunity. Equipment should be designed to ensure th at s p ills and leaks w ill be contained w ith a minimum of worker exposure. Small s p ills may be contained by a sorbent; spent sorbent should then be disposed of in a safe manner. If s p ills must be removed by hand, only workers who are in stru cted and trained in safe decontam ination and disposal procedures should supervise and perform cleanup. Employers must supply appropriate personal p ro tectiv e equipment and ensure th a t workers understand how to use i t .
Dried ta r is d if f ic u lt to remove from su rfaces. For th is reason, e a sily strip p a b le coatings may be used where ta r may s p ill. Because such coatings do not adhere w ell, the ta r can be removed w ith the coating. The clean surface can then be recoated. In some p la n ts, where such coatings are not used, manual scraping and chipping, commercial clean sers, or steam have been used . These methods fu rth e r increase the hazard to cleanup personnel.
For example, steam strip p in g may generate airborne contam inants, as w ell as increase the p o te n tia l for burns. For these reasons, steam strip p in g is discouraged. Where organic solvents are used for cleanup, sp ecial care is necessary to lim it exposure to solvent vapors and aero so ls. This may include the use of lo cal v e n tila tio n and approved re s p ira to rs .
Hand tools and portable equipment may be contaminated and should be cleaned before reuse. They can be steam-cleaned in an enclosed system or cleaned by vapor degreasing and u ltraso n ic a g ita tio n . The residue should be contained and disposed of properly, and solvents should be w ell co n tro lled .

# Personal Hygiene
Where engineering controls are inadequate to prevent exposure, workers should be extrem ely a le r t to the p o te n tia l hazards of d ire c t contact w ith coal-derived products. They must exercise good personal hygiene by (1) avoiding touching th e ir faces, g e n ita ls, or re c ta l areas w ithout f i r s t washing th e ir hands; (2) washing skin w ith soap and w ater a fte r d ire c t contact w ith coal-derived products; and (3) washing th e ir hands, forearm s, face, and neck a fte r completing each operation where th ere was known or suspected contact w ith coal-derived products. Workers must also be a le rt to sores th a t do not heal properly, dead skin, and changes in w arts and moles. A ll suspicious lesio n s should be reported immediately to the medical department because they may be early signs of cancer.
To ensure good personal hygiene in p la n ts, workers must take showers at the end of each s h if t. Workers should thoroughly wash th e ir h a ir and h a irlin e during showers and should c a re fu lly clean skin creases and fin g e rn a ils. Double locker rooms are also necessary to segregate contaminated clothing from s tre e t clothing . Employers should provide an adequate number of washrooms throughout the p lan t and encourage th e ir use. Washrooms should be close to lunchrooms so workers can wash before eatin g . Employers should ensure th a t lunchrooms remain uncontaminated to minimize the likeliho od of in h alatio n or ingestion of coal-derived products. Employers should req uire workers to remove contaminated p ro tectiv e clothing and wash before entering the lunchroom. Bar soap should be provided in a l l plant showers, and lanolin-based or equivalent w aterless hand cleaners should be provided in a ll p lan t washrooms and in the locker f a c ility . Organic solvents should not be used, because they may cause the contaminants to fu rth e r penetrate the skin and they are in h eren tly toxic in many cases.
V PERSONAL PROTECTIVE EQUIPMENT AND CLOTHING Design of coal liq u efactio n p lants must focus on engineering controls to e ffe c tiv e ly minimize worker exposure to coal-derived products. In thost instances where engineering controls do not provide adequate p ro tectio i (mechanical breakdown, for example), good work p ra ctice s become the primary means of safeguarding h ealth . I f the work p ra ctice s are also inadequate and workers are d ire c tly exposed to coal-derived products, i t may be necessary to use personal p ro tectiv e equipment and clo th in g .

# R espiratory P rotection
Use of re sp ira to rs for p ro tectio n is acceptable only when engineering controls and standard work p ra ctice s are im practical and cannot be improved. Because coal liq u efactio n is a fled g lin g in dustry , th ere should be few circum stances where equipment needs to be r e tro fitte d to improve engineering co n tro l. Id e ally , equipment should be in itia lly designed to provide adequate co n tro l. However, if design is inadequate and engineering controls do need to be in sta lle d a fte r p lan ts are in operation , re sp ira to rs must be used u n til engineering controls are in e ffe c t. Other circum stances during which re sp ira to rs may be necessary for short periods include m aintenance, emergencies, leaks, s p ills , and f ir e s .
When re sp ira to rs are used, they should reduce in h alatio n and in gestio n of airborne contaminants and provide li f e support in oxygen-deficient atmospheres. Although re sp ira to rs are useful fo r reducing exposure to hazardous m ateria ls, they have several undesirable asp ects. Problems associated w ith using re sp ira to rs include poor communication and hearing, reduced fie ld of v isio n , increased fatig u e and reduced worker e ffic ie n c y , s tra in on h eart and lungs, skin ir r ita tio n or d erm atitis caused by p e rsp ira tio n or fa c ia l contact w ith the re s p ira to r, and discom fort. Medical screening should be conducted to determ ine a w orker's a b ility to wear a re s p ira to r. F acial f i t is c ru cia l fo r e ffe c tiv e use of most negative pressure re s p ira to rs, because i f leaks occur, a ir contam inants may be inhaled. F acial h a ir, such as beards or long sideburns, and fa c ia l movements can prevent good re sp ira to r f i t ; th erefo re, i t is im portant th at carefu l f i t te stin g be conducted to assure an adequate f i t .
Training workers to properly use, handle, and m aintain re sp ira to rs helps to achieve maximum effectiv en ess of re sp ira to ry p ro tectio n . Minimum tra in in g requirem ents for workers and supervisors have been estab lish ed by the Department of Labor (29 CFR 1910.134). These requirem ents include handling the re s p ira to r, proper f ittin g , te stin g facep iece-to -face se a l, and wearing the re sp ira to r in uncontaminated workplaces during a long t r i a l period. This tra in in g should enable the worker to determ ine whether the re s p ira to r is operating properly by checking i t for c le an lin e ss, leak s, proper f i t , and spent c artrid g es or f i l t e r s . Employers should impress upon workers th at re sp ira to ry pro tectio n is necessary if engineering controls are not su ffic ie n t.
R espirator facepieces need to be m aintained reg u larly to remove contam ination and to slow down the aging of rubber p a rts. Employers should consult the m anufacturers' recommendations on cleaning methods, and care should be taken not to use solvents th at may d e te rio ra te rubber p a rts.

# Gloves
Gloves are usually worn a t coal liq u e fa c tio n p ilo t p lan ts in cold w eather, when heavy equipment is handled, and in areas where there is hot process equipment. Where gloves w ill not cause a sig n ific a n t safety hazard, they should be worn to p ro tect the hands from process m ateria ls. Gloves made of several types of m aterials have been used in coal liq u efactio n p ilo t p la n ts, including cotton m ill gloves, vinyl-coated heavy rubber gloves, and neoprene rubber-lined cotton gloves.
No q u a n tita tiv e data on glove pen etratio n by coal liq u efactio n m aterials have been reported. One should assume, however, th at gloves and other p ro tectiv e clothing do not provide complete p ro tectio n ag ain st skin contact. To prevent contam ination of glove lin in g s, workers should wash th e ir hands before p uttin g on gloves. Because penetratio n by toxic chemicals may occur in a re la tiv e ly short tim e, gloves should be discarded follow ing noticeable contam ination. Work Clothing and Footwear Work clothing and footwear can reduce exposure to coal-derived products, esp ecially heavy o ils . Work clothing should be supplied by the employer. The clothing program at one coal liq u e fa c tio n p ilo t p lant provides each process-area worker w ith 15 se ts of s h ir ts , slack s, T -sh irts, underpants, and cotton socks; 3 jack ets; and 1 rubber rain co at . In another f a c ility , thermal underwear for use in cold weather was provided . Work clo th in g , including workshoes and hardhats, should be changed a t the end of every w orkshift or as soon as p ossib le when contam inated.
A ll work clothing and footwear should be le f t at the p lan t a t the end of each w orkshift, and the employer should be responsible for handling and laundering the garments. Because of the volume of laundry involved, on s ite laundry f a c ilitie s would be convenient. Any commercial laundering establishm ent th at cleans work clothing should receive o ral and w ritten warning of p o te n tia l hazards th a t might re s u lt from handling contaminated clothing . Operators of coal liq u efactio n p lants should req u ire w ritten acknowledgment from laundering establishm ents th a t proper work procedures have been adopted.

# Hearing P rotection
In c e rta in in stan ces, engineering controls w ill not be adequate, and exposure-to-noise le v e ls exceeding the NIOSH-recommended lim it (85 dBA for an 8-hour period) may occur in some areas. Under these circum stances, workers should be provided w ith p ro tectiv e devices to prevent hearing lo ss.
There are two basic types of hearing protectors available: earmuffs that f i t over the ear and earplugs that are inserted into the ear. Workers should choose the type of hearing protector they want to wear. Some workers may find earplugs uncomfortable, and others may be unable to wear earmuffs with th e ir glasses, hardhats, or re sp ira to rs.
A hearing conservation program should be established. As part of th is program, workers should be instructed in the care, use, and cleaning of hearing p ro tecto rs. The program should also evaluate the need for protection against noise in various areas of the plant and provide the workers with a choice of hearing protectors su itab le for those a re a s. Workers should be cautioned not to use earplugs that are contaminated with coal liquefaction m aterials.

# Eye and Face Protection
Eye and face protection, such as safety glasses and faceshields, should be provided for and worn by a ll workers engaged in a c tiv itie s in which hazardous m aterials may contact the eyes or face. In addition, fu ll-len g th p la stic faceshields should be worn in areas where contact with ta r or tar o il is lik ely , except when fu ll-facep iece re sp ira to rs are being worn. Emergency personnel should also be train ed according to guidelines in 29 CFR 1910, Subpart L, giving sp ecial a tte n tio n to systems handling coalderived m aterials and to any associated sp ecial procedures. Inform ation on sp ecial fire fig h tin g and rescue procedures, p ro te c tiv e clothing requirem ents, and breathing apparatus needs should be d istrib u te d fo r areas where m aterials might be released from the process equipment during a f ir e or explosion. These procedures should be incorporated in to w ritten standard operating procedures, and copies should be given to a ll emergency personnel.

# EMERGENCY PLANS AND PROCEDURES
P lant emergency services should be adequate to control such situ a tio n s u n til community-provided emergency services a rriv e . Where a community f ir e department is staffed w ith permanent, p ro fessio n ally train ed workers, a plant manager may rely more on the emergency serv ices of th at departm ent. When community services are re lie d on for emergency situ a tio n s , the p lant emergency plan should include provisions for close coordination w ith these se rv ic es, frequent exercises w ith them, and adequate tra in in g in the p o te n tia l hazards of various systems in the p lan t.
Emergency medical personnel, such as nurses or those w ith f ir s t-a id tra in in g , should be present a t the plant a t a ll tim es. Immediate response is needed when a delay in treatm ent would endanger l i f e . These cases may involve in h alatio n of toxic gases such as hydrogen su lfid e or carbon monoxide and asphyxiation due to oxygen displacem ent by in e rt gases such as nitrogen.