Document K64ajKD2raOND0JdDbqNk01b6

FILE NAME Household Contact HC DATE 1952 DOC HC009 DOCUMENT DESCRIPTION Dept of Labor Report - Safety and Health Standards SAFETY AND HEALTH | STANDARDS Loa For Contractors performing Federal Supply Contracts under the Healey Public Contracts Act Rael a 4 po UNITED STATES DEPARTMENT OF LABOR MAURICE J. TOBIN Secretary Wage and Ilour and Public Contracts . Divisions WM R. McCOMB Administrator WASHINGTON D. C. UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON 1952 FOREWORD gamma y eae Spe L The Healey Public Contracts Act requires that contracts entered into by any agency of the United States Government for the manufacture or furnishing of materials supplies articles and equipment in any amount exceeding 10,000 must contain among other provisions a stipulation that No part of such contract will be performed nor will any of the materials supplies articles or equipment to be manufactured or furnished under said contract be manufactured or fabricated in any plants factories buildings or surroundings or under working conditions which are insanitary or hazardous or dangerous to the health and safety of employees engaged in the perform- ance of the contract * * " This booklet contains three parts Part I sets out the principal factors which have induced managements to install systematic safety programs and lists the basic day day accident prevention practices employed ; parts II and III set out the minimum safety and health standards respectively which will be applied by the Secretary of Labor and the Administrator of the Wage and Hour and Public Contracts Divisions in determining whether in specific cases Government contracts are being performed under safe and sanitary conditions as required by section 1 e of the act These standards are based to a large extent on standards approved by the American Standards Association and safety and health codes adopted by a number of States and generally represent what ; : have been shown by industrial experience to be reasonable minimum standards for safety and health Changing industrial processes and materials may introduce new safety and health i hazards which require constant attention if a realistic preventive program is to be car- i ; ried on Space limitations of this bulletin permit compilation only of those standards relating to safety and occupational health problems which are commonly met by employ- ers and preclude inclusion of materials relating to uncommon hazards or situations The measures to be taken to meet uncommon hazards should be reasonable in the light of the circumstances Further these standards are not in any way intended to limit or super- sede State or local safety and occupational health codes and where such codes provide stricter or more exact standards compliance with such higher standards will be deemed compliance with the Public Contracts Act Some of the types of work discussed in this bulletin involve hazardous occupations for which higher minimum ages are provided under State child labor laws or the child labor provisions of the Fair Labor Standards Act than under the Healey Public Contracts Act The higher age limits prescribed for such hazardous occupations under such other laws are not superseded or modified by the safety standards con- tained in this bulletin The failure to maintain proper safety and health standards in the performance of i contracts subject to the Public Contracts Act constitutes a breach of contract which ; may provide the basis for cancellation of the contract and makes the party responsible for such breaches subject to the ineligible list sanctions provided in the act : These standards were prepared by the Bureau of Labor Standards in cooperation with the Wage and Hour and Public Contracts Divisions and the Office of the Solicitor and checked for adequacy and suitability for use in the States with representatives of typical State labor departments Assistance on the sections concerning occupational health requirements was furnished by the Division of Industrial Hygiene of the U. S. Public Health Service We wish to take this opportunity to thank these officials for their assistance in making this publication possible PART SAFETY AND HEALTH PROGRAMS PAY DIVIDENDS Hard cold statistics on industrial accidents times the direct costs The items of cost that in the United States tell a tragic and revealing are likely to be present in each case of acci- story These figures deal with the number of dental injury are people killed and injured in industrial accidents Sometimes figures are used to estimate the 1. Compensation 2. Medical expense billions of dollars that are lost by management and by workers and their families as a result of accidents 3. Lost time of injured employee 4. Lost time of fellow employees work who stop But there are no statistics on the human suf- a To aid injured worker fering sorrow and misery which follow deaths b Out of sympathy or curiosity UF and injuries into the homes of American work- c For other incidental reasons NAM, ers even though the human tragedy which stalks after industrial accidents affords the 5. Time of foreman executives or other staff personnel most impelling reason for intelligent safety a Assisting injured employee programs Although the most important consideration in any safety program is the safety and wellbeing of the worker and the protection of his family from want another driving force behind industrial safety programs is the cost of accidents in terms of money and human re- sources tragic economic waste A third reason for undertaking good safety programs applies primarily to contractors per- b Investigating cause of accident c Arranging for continuance of injured employee's work d Selecting training or breaking in new employee e Preparing accident report f Attending hearings on injury serious or contested cases 6. Lost production due to upset shock or diverted interest of workers forming on certain Government supply contracts of 10,000 or more subject to the safety requirements of the Healey Public Contracts Act Part I represents in briefest form basic information drawn from the day practice of managements whose safety performance deserves grade ranking in terms of the elimination of employee injuries While more information could well have been included this presentation was purposely limited to a few major items for greater emphasis 7. Lost production due to stoppage of machine or process in charge of injured person 8. Damage to machine equipment or material directly occasioned by the accident 9. Spoiled product or material due to emotional upset of fellow workers 10. Lessened effectiveness of injured employee for a period after his return to work 11. Business or good will lost through failure to fill order on time lost bonuses payment of forfeits for nondelivery etc. A. ACCIDENT COSTS Accidents are expensive They constitute a serious wastage of our human and material resources Substantial savings of both can be made by preventing accidents They can be pre- 12. Legal expense court fees expense of preparation of case settlements judgments etc. in cases contested at law 13. The employer's share of the loss and expense to society in each case of death or continued loss in earning power vented by appeals to the emotions and by persistent day effort to enlist on the side B. MANAGEMENT'S PART IN HEALTH of safety the present desire and necessity AND SAFETY that every management has for reducing waste Everyone can easily see that accident costs are wholly waste It is not so easy to see how large are these wastes Compensation and medical costs spoken of as direct costs are obvious It has however taken careful studies by experienced cost accountants and industrial executives to show how large are the other costs spoken of as indirect costs It is now clear that on the average the indirect costs of accidents in industry are not less than four Safety work in industry must begin at the top Since every kind of work that men do in- volves some degree of hazard each produces its share of injuries But by the proper attention to safety almost all injuries can be prevented in any kind of work and in any occupation Management's desire to eliminate injuries should be strong enough to make their prevention a vital part of all activities Prevention must receive continuous attention along with such matters as cost quality and production Da ee Very briefly the more important definite things that the management should do to pre- vent accidents may be set down as follows 1. Provide safe plant and equipment 2. Safeguard all machinery 3. Place no new machinery or equipment in practices The committee should meet at least monthly and keep a written record of the number and nature of its recommendations the incompleted number carried out the number and the number not acted upon The members of the committee should be selected from the vari- operation unless full attention has been paid to its safety ous departments and should be changed at regu- lar intervals 4. Plan and arrange all processes and opera- tions with careful attention to safety The advisable committee set depends chiefly upon the size of the establishment but 5. Maintain a system of inspection to discover other factors have a bearing such as the prog- e correctible hazards ress that has been made in safeguarding the ee 6. Maintain minded supervision plant when committee work is started the size nC 7. Train educate and stimulate its employees and relationship of the various departments or to follow safe methods of work and take a sin- plant units the type of business manufacture cere interest in the safety of themselves and construction transportation public utilities their fellow workers etc. However at least the following funda- RUE 8. Investigate all accidents to determine how mentals should be met in forming the committee best to prevent a recurrence or committees decided upon NalinOh 9. Make a full report to the proper authori- Mme ties of all cases of injury a Each committee should be so made up FNP as to have standing appropriate to nr C. THE WORKER'S PART IN HEALTH ted Y AND SAFETY its field of work For instance a main or governing committee should TODG Safety is everybody's business Every em- include such key executives as mas- SARA ployee should of course be always alert to the ter mechanic and production mana- al e possibilities of injury Management can do only ger A workers committee should be nh ot part of the job Each worker should faithfully made up of members well known to Oa: cooperate with his management in all safety and having the respect of their fel- ADE programs Some of the ways in which his help low workmen " a is most necessary are b The committee membership should Ne Sacto 1. Faithfully using all safeguards provided 2. Studying and carefully following safety NAR rules and safety instructions encompass the maximum in knowl- edge of the methods practices and conditions in the plant undertaking Aseove! 3. Working earnestly on safety committees or group represented we or other safety activities to which he c The committee should be as small as is MEN assigned may be consistent with the above require- AAD RCC 4. Seeking always for the safe of ments A committee of three func- ing on each job or activity way work- tions more effectively than one of TW 5. Watching out always for the safety of his five The larger the committee the fellow men more the debate and the less the , 6. Reporting all hazardous conditions of action which he learns When a committee is formed certain matters D. HEALTH AND SAFETY of policy and procedure should be definitely set COMMITTEES forth in writing Written instructions should A safety committee when properly set up and cover at least maintained can be an extremely effective tool for accident prevention The functions of such a Scope of committee activity vin) a committee should include the b Extent of committee authority caer for periodic inspections of the planrtesrpeonvsiiebwilaintdy c Procedure as to rs approval of inspection reports analysis of rac causes of accidents for the purpose of submit- 1 Time and place of meetings 2 Frequency of meetings ting recommendations to prevent recurrence of 3 Order of business or similar accidents instructing new employces 4 Records to be kept or workers transferred to unaccustomed 5 Attendance requirements tasks to the hazards of their work and promoting the education A committee will take its work seriously in of all employees in safety proportion to management's attitude toward it A management that sets up a committee to ac- complish a specific purpose makes it clear that it wants results and gives effective executive supervision to its activities will get satisfac- tory results therefrom Effective committee conduct of safety work in the absence of executive leadership is possible only when committee members have unusual initiative and determination to advance the cause of safety In such instances they often convert the nonsafetyminded management Sometimes the salesman of safety failing to arouse adequate management interest can accomplish his purpose by getting a safety committee organized and aid it to plan a program that will interest the top management thus at the same time getting safety work started E. ACCIDENT INVESTIGATION It is obvious that every case of disabling injury should be carefully investigated to find out how to prevent a recurrence In theory every accident whether it yields an injury or not should be investigated also but this would involve such a heavy volume of work that few managements would find it practical Good practice is to investigate all cases of disable- ment all other happenings involving the probability of serious injury and cases of repeated injury to an individual The investigations must be made by persons who are intelligent painstaking and keenly minded Usually an accident has more than a single cause A combination of circum- stances was necessary to bring it about The employer should try to correct every condition or circumstance that might lead to injury He should particularly not be content to stop with finding the human fault or failure that was involved for in almost every case both a mate- rial and a human fault will be found If the material fault or lack is corrected the human fault or lack usually fails to produce injury Of course effort should be made to correct the human fault also Usually correction of the material or mechanical fault involves expense so that the constant temptation is to blame the individual at fault and let the matter end there That is not in the best interests of safety and the tendency to take that course must continuously be resisted F. ACCIDENTS ARE PREVENTABLE An excellent definition of accident is that it is an unexpected occurrence that is unplanned for or unforeseen Occasionally human injury is involved and we have an accidental injury which is what we really mean when we say accident If each bit of work done in in- dustry could be properly planned and then carried out exactly as planned there would be no unexpected occurrences and therefore no human injuries Numerous establishments large and small in each branch of industry have by planning foresight and care eliminated at least 9 out of every 10 injuries that otherwise would have been suffered by their workers and have profited by so doing PART REQUIREMENTS Records of Injury Frequency Rate Every person who is or shall become a party to a Government contract which is subject to the provisions of the Healey Public Contracts Act and the regulations thereunder or who is performing or shall perform any part of such contract subject to the provisions of such act or regulations shall maintain injury fre- quency rates as defined herein and such rates shall be calculated quarterly on a calendar basis commencing the first of January of each year Such records shall be kept on file for at least three years after the date of entry thereon and shall be made available for inspection by authorized representatives of the Secretary of Labor Frequency Rate frequency rates are the primary measures of the incidence of work injuries The lack of comparability inherent in simple injury totals arising from variations in employment and operating time is overcome by expressing the injuries in terms of a standard unit of exposure By definition the standard comparison frequency rate is the average number of disabling work injuries per million employeehours worked Expressed as a formula it is Frequency Rate Number of disabling injuries multiplied by 1,000,000 Total number of employee worked What Injuries To Count A disabling work injury is defined as any injury incurred in the course of and arising out of employment which 1 Results in death or 2 Results in any degree of permanent physical impairment regardless of whether or not any time is lost from work or 3 Renders the injured person unable to work at any regularly established job which is open and available to him throughout the hours of his regular shift on any day after the day of injury including Sundays holidays and days on which the plant is shut down an injury for statistics purposes is in no way related to the eligibility of the injured person for workmen's compensation payments In case of doubt as to whether or not an injured person is able to work the attending physician's decision is final The injuries described in items 1 and 2 of this definition are commonly spoken of as death cases and permanent disability cases Death cases usually are readily identified Permanent disabilities likewise are usually easy to identify It is necessary however to remember that permanent disabilities include not only all Establishments participating in the Bureau of Labor Statistics quarterly injury survey and retaining on file copies of each com- pleted report on Form BLS 1417 or 1417 will be considered as complying with the requirement regarding the maintenance of injury fre- quency rates injuries involving the amputation of any part of the body but also all injuries which result in the complete or partial loss of use of any body part or function of the body For example the partial loss of vision or a permanently stiff arm resulting from a poorly healed fracture would be counted as permanent impairments just as you would count an injury involving the ampu- For every use the frequency rate affords the best measure of performance because each accident might easily but for the grace of God have been very serious or fatal and therefore the constant effort must be to prevent every injury not just the more serious ones The following example shows how to figure the frequency rate tation of a finger or a foot Most permanent disability cases involve the loss of considerable time Occasionally however there are hardy individuals who experience a minor permanent disability such as the amputation of the end of a finger and return to work on the same day During 1949 eighteen time injuries occurred in a certain machine shop The number of hours worked during the year totaled 216,000 What was the frequency rate Sub- stituting these numbers in the frequency rate formula we get or the following day Regardless of the fact that no recorded time was lost these cases should be counted if there actually is any residual permanent impairment of any body part or body function The third category of disabling injuries is 18 x 1,000,000 = = 216,000 which gives a frequency rate of 83 plus That is the men in the shop suffered 83 time injuries for every million hours they worked referred to as temporary disabilities If the figure for hours is not available They are temporary disabilities because they a close enough estimate can usually be made by do not result in death or any form of perma- multiplying the average number of workers by nent impairment In other words they are in- the hours worked per week and the number of juries from which the injured person eventually weeks worked for the period for which the fre- recovers with no lasting ill effects At the same quency rate is being calculated time they are total disabilities because they Some people prefer to think of the frequency render the injured person totally unable to rate in terms of how long a person may expect est, work at any regular job for a period of time to work on the average without getting hurt BI equivalent to at least one full shift on any day If in the above example the shop worked a a after the day of injury The important things hour week 50 weeks during the year each to remember in connection with these injuries man worked 2,000 hours in the year and there- trae are 1 Time lost on the day of injury is not fore in order to put in 216,000 hours there must considered in determining whether or not an have been an average of 108 men working The injury is disabling 2 the inability to work 18 injuries averaged among these 108 men must continue throughout the hours of the means that every sixth man was disabled dur- worker's regular shift on at least one day but ing the year Another way of putting it is that 3 this inability to work may occur on any on the average each man could expect to be day after the injury not necessarily on the next disabled once in 6 years That is a very high day and not necessarily on a day on which he injury rate for even the most hazardous work would normally be expected to work Numerous plants in all branches of industry The reference in the definition to a regularly maintain frequency rates below 10 and often established job means that you are not per- times below 5. A worker in a plant having a ee mitted to exclude an injury from the count of frequency rate of 5 is fortunate indeed for on disabling injuries if the injured person returns the average he can expect to work three life- to a specially created easy job which was de- times a whole century each disabling abd signed simply to get him back to work without injury he suffers He is undoubtedly much safer OE loss of time when at work than when not at work It should also be noted that under the defini- tion of a disabling injury the reportability of For full detailed information on deter- mining mining frequency rates see American Stan- | * @ dard Method of Compiling Industrial Injury Rates Z16.1.1 B. BUILDINGS AND EQUIPMENT 1. Buildings and all appurten- . ances thereto including bridges towers balconies runways and platforms should be structurally safe to prevent collapse 2. Floors No floor or platform should be so loaded as to have a factor of safety of less than four That is the weight placed upon a floor or platform should not exceed fourth of the breaking strength of the platform or floor flo r b Floors other than those resting direct- ly on solid ground when used for storagoer for operations that might lead to overloading should be clearly posted to show maximum safe floor loads c All floor surfaces should be kept clean and dry and maintained in a smooth and rea- sonably nonslippery condition free from holes or projections that might cause tripping d Where the type of operation necessi- tates working on wet or slippery floor areas such areas should be protected against slipping by the use of mats grates cleats or other high friction floor coverings e tions Safe means of access suited to condi- should be provided to every overhead point to which employees are called upon to go in connection with their employment Materials or objects should not remain unnecessarily on the floor surface in such places as will subject employees to the hazard of falls 3. Floor openings wall openings and ele- vated platforms openings wall openings and elevated platforms where there is a possibility of persons or material falling through should be provided with standard railing and toe boards or with wood or metal covers Where guard rails are advisable refer to Standards for Railings Toeboards and Guards as specified under Part II E Machine Guard- ing 4. Stairways or Steps Riser height and tread width should be uniform in any given flight of stairs Variations in riser height should not exceed 1/8 inch in the stair as con- structed Variation due to wear should not be allowed to exceed 1/4 inch Riser height should not be over 8 inches and tread width exclusive of nosing not less than 9 inches Preferred dimensions are riser 7 inches tread 11 inches plus 1 inch nosing and width not less than 36 inches b Every stairway or steps of four or more risers risers should be equipped with a substantial smooth handrail from 30 inches to 36 inches high measured vertically from the nose of the Published by American Standards Association 70 E. 45th St. New York City tread and placed on the hand side as one mounts the stair and on the open side if any If 5 feet or more in width or open on both sides side the stairs should have a handrail on each c Interior stairways or steps which are more than 8 feet wide should be divided by cen- ter rails into widths of not more than 8 feet nor less than 3 feet 8 inches d Exterior stairways or steps should have a handrail at each side and if the stairway or steps are more than 88 inches wide one or more intermediate handrails should be provided e Railings on open sides of stairways or steps should be provided with an intermediate rail at midheight or with vertical members having a maximum spacing of 11 inches f Every stairway or steps should be maintained in good repair free from protruding bolts screws and nails and unnecessary material dirt and slippery conditions Treads should be renewed when the surface including the nosing shows wear to the extent of 1/4 inch or more g Stairways should not be used for storage purposes and any equipment should be so located that its presence or use will not unnecessarily obstruct or interfere with free pas- sage h All metal treads should have a surface which will reasonably prevent slipping 5. Elevators Elevator inspection by a recognized elevator inspection service will be acceptable as evidence of satisfactory installation and maintenance Hoistways hatchways elevator wells and wheel holes should be secure- ly fenced inclosed or otherwise protected For details see American Standard Safety Code for Elevators Dumbwaiters and Escalators b Elevator machinery electrical apparatus or system wiring should be properly in- stalled guarded and inspected 6 Illumination Illumination adequate to permit all work activities to be carried on safely should be provided and maintained during all work periods Minimum standards for illu- mination should be in conformance with the American Standard Recommended Practice of Industrial Lighting 7. Aisles and passageways Permanent aisles and passageways should be kept clear and in good repair Where due to lack of proper definition such aisles and passageways become hazardous they should be clearly defined by painted lines curbings or other methods of marking b Where industrial trucks are in custom- ary use way traffic aisles should be at least 2 feet wider than the widest vehicle Two traffic aisles should be at least 3 feet wider than twice the width of the widest vehicle c There should be no obstructions across or in aisles that might cause tripping 8. Ladders Full compliance with the applicable provisions of the American Stan- such to sible equipment wherever reasonably pos- dard Safety Code for Wood Ladders A14.1 is recommended b Rung spacing on each fixed ladder should be uniform This includes the space between the top rung and the landing measured vertically from the top rung Rungs of all ladders should be uniformly spaced firmly secured and maintained in a sufficiently condition to prevent turning or other motion Bent rungs of metal fixed ladders should be promptly replaced or repaired Clearance at the back of rungs of fixed ladders should not be less than 6inches measured horizontally from any ob- ject c Fixed ladders should be secured with sufficient firmness and in such manner that they will be free from visible motion under normal conditions of use Hand holds should be pro- vided at the top of each fixed ladder so arranged that a person using them can conveniently retain a secure hold with either hand when stepping from the top rung of the ladder to the landing point or the reverse Side rails should extend above landings at least 3 feet No fixed ladder should have a slope outward that is from the vertical toward the climber unless such sloping ladder or sloping part thereof is Good design eliminates overhead locations to the maximum practicable extent 2 Nature of Devices that require rather frequent as weekly servicing usually involving only minor attention or adjustment Examples Ring oiler or equivalent bear- ings fans induction motors storage tanks exhaust Suggested safeguards and toeboard- ed platforms reached by stairs should be provided wherever space and location permits Fixed ladders are preferable to stairs steeper than will give a 10 inch rise and 8 inch tread pitch about 51 Where location prevents stair or fixed ladder provide portable railed step or portable ladder suited to the purpose with hooks fixed to the rails to engage suitable supports at the platform 3 Nature of Apparatus that requires daily or more frequent servicing Examples Control devices as governors regulators recorders sight glasses etc. Suggested safeguards such point should be accessible by a platform and stair In some cases they can be serviced from the floor Example Use of telescope to read ther- mometers on tall apparatus properly caged Ladders in disrepair should be promptly repaired or removed from use d In the use of portable straight ladders practicable precautions should be used Every step ladder should be equipped with a spreader of a type that locks when the ladder is opened to hold it securely in the open position Portable steps and saw horses should be of substantial 4 Nature of Equipment that requires relatively infrequent attention but which involves major cleaning or maintenance and repair work Examples Electric overhead traveling cranes overhauling steam boilers retubing cleaning tubes stills fractionating columns digesters etc. Suggested safeguards and toe- Man construction with parts firmly secured and boarded platforms reached by stairs wherever SE maintained in a safe state of repair possible Particularly in crane overhauls such SaMETUB 9. Overhead work Every overhead platforms cut the cost of the work result in a job that may have to be done in an establish- better maintenance and reduce the hazard ment should be carefully considered and a safe thus justifying very substantial expenditures fe means of doing it provided for the platform If fixed platforms are not b Some of the more common overhead practicable provide substantial knock jobs with means of safeguarding are given below scaffolding railed and toeboarded kept for the purpose In some cases wheeled platforms 1 Nature of Devices that require only infrequent attention normally consisting of only simple servicing or adjustments Examples Valves in steam air or other supply ; lines ; pressure reducers overflow or other high level storage tanks liquid level indicators gauges natural draft ventilators Suggested safeguards -Portable -Portable ladders Feet suited to floor surface ladder of correct length strength and condition conveniently available firm support at top security of position safety in placing ladder safety of man on ladder position clearance from mov- e intgc.parts electrical conductors steam pipes Good practice provides fixed ladders or stairs wheels arranged to lock are convenient 5 Nature of Apparatus out of doors Assignable to above classes but listed here because of the special hazards due to wind ice cold etc. Example Sprinkler tanks oil storage tanks derricks coal unloaders dust collectors advertising signs flood lights Suggested safeguards outdoor tanks should be equipped with fixed ladders and self- draining platforms if needed to give safe access to manholes etc. Means of access to bearings etc. on derricks and coal unloaders must be suited to conditions Never omit lad- der rails or allow ladder to have reverse slope provide adequate hand holds and foot supports 6 Nature of Maintenance activities as window cleaning and reglazing paint- ing replacing lights painting masonry oiling and other work on overhead shafting Suggested safeguards Window cleaning equipment should conform to the American Standard Safety Code for Window Cleaning Long spout oil cans can be used instead of " ladders The practice of oiling running over- head machinery is rarely carefully planned When donc from a crane a railed platform should be provided and careful precautions taken to guard against insufficient clearance Extension fittings should be used to give ade- quate clearance from moving parts 10. Housekeeping and order Satis- factory control requires careful consideration of such factors as tonnage and volume of mate- rials to be handled the amounts required at the successive steps of the process allowance of the spaces necessary and the methods to be used in handling and transporting the materials and articles b Methods of piling should be worked out for each class of materials or articles Points commonly of importance are 1 Height of This is dependent up- on the character of the material and the con- sequent danger of toppling the means used in piling and removal the traffic nearby and interference with sprinkler operation When the nature of the material is suitable it should be so piled as to be interlocking 2 Strength of Allowable floor loads should be posted 3 Evenness of support and its continued stability This condition often exists in yard piling where uneven ground or moisture may cause toppling and on first floors or in base- ments where floors may slope or flooring sag 4 Location traffic or the presence of work benches or machines may make it necessary to limit the height of material to be piled in a safe manner 5 Piling small articles Containers suit- ed to the nature of the articles are commonly used These usually take the form of wheeled or truck pick containers that receive the articles from work bench or machine A useful modification for such articles are small cans or trays that themselves may be stacked 6 Pipe or other long Suitable racks aid handling Projecting ends should be protected by location railings or barriers c Remove or bend over in such a manner as to make them harmless all projecting nails in kegs barrels boards or boxes allowed to re- main about the work place d Waste disposal provisions should be made for the orderly collection and disposal of all scrap debris empty bottles etc special pro- visions suited to the nature of the substance in question should be made for the disposal of poisonous and obnoxious substances 11. Yards and grounds plant and grounds safety measures include 1 Proper drainage 2 Clearance signs to warn of limit yards clear- ances 3 Derails and bumper blocks 4 Traffic control signs to warn pedestrian vehicular and railroad traffic 5 Proper coverings or rails for open pits tanks vats ditches etc. 12. Material-s a Materials wherever stored should be piled stacked or racked in a manner designed to prevent tipping falling collapsing rolling or spreading Racks bins planks sleepers bars strips blocks and sheets should be used where necessary to make the piles stable Materials and objects that are stored in overhead places should be secured so that they will not fall and cause injury to per- sons below b All hazardous chemicals should be distinctively marked to indicate their nature 13. Compressed Gases Cylinders containing compressed gases should not be unduly exposed to the heat of stoves radiators or furnaces Where cylinders are stored in the open they should be protected from accumulations of snow and ice and from the sun where high temperatures occur b Heat increases the pressure within the cylinder or it may melt the fusible safety plugs which in acetylene cylinders melt at a temperature of approximately 210 to 220 Should a valve become frozen it should be thawed out with warm not scalding water Open flames should not be used for this pur- pose under any circumstances c Cylinders should preferably be stored in an upright position In many plants cylinders are held upright by straps or chains to prevent their falling over This is particularly important with acetylene cylinders d Empty cylinders should be plainly marked EMPTY and the valves should be closed The empty cylinders should be segregated from full cylinders and returned to the manufacturer as soon as practicable e The recommendations of the National Fire Protection Association and State and municipal laws and regulations should be closely observed in regard to the storage of compressed gas cylinders Cylinders should never be allowed to fall or otherwise receive shock 14. Special precautions for oxygen cylinders Great care must be exercised in handling oxygen to prevent contact of oxygen under pressure with oils greases organic lubricants rubber or other materials of an organic nature in order to prevent explosion The following recommendations of the Compressed Gas Association should be observed 1 Never permit oil grease or readily combustible materials to come in contact with oxygen cylinders valves regulators gauges or fittings 2 Never lubricate regulators fittings or gauges with oil or any other combustible sub- stance . 3 Never handle oxygen cylinders or apparatus with oily hands or greasy gloves or rags . 4 Always clear the particles of dust and dirt dirt from the opening to each cylinder by slightly opening and closing the valve before applying any fitting to the cylinder 5 Never permit oxygen to enter the regu- lator suddenly Open the valve slowly When opening the valve point the face of the gauge on regulator away from the operator 6 Never drape an oxygen cylinder with etc. material such as wearing apparel rags etc. 7 Never use oxygen fittings valves regulators or gauges for any other service except oxygen 8 Users should never mix gases of any type in an oxygen or any other cylinder 9 Never use oxygen from a cylinder except through a pressure reducing regulator 10 Never attempt to use regulators which are in need of repair or cylinders having valves which do not operate properly 11 Never attempt to repair defective oxygen equipment unless properly qualified by knowledge and experience 15. Flammable Materials such as paints lacquers thinners gasoline and nap- tha should be stored and handled with provi- sions for safety suited to the material and the conditions of its use They should also be covered or stored in an approved type of safety container suitable to the nature of the material 16. Explosives - Explosives should be stored in approved type explosive magazines which are bulletproof ventilated and located at distances from other buildings as required under the American Table of Quantity and Dis- tance For details refer to U. S. Bureau of Mines Information Circular 7307 on Surface Storage of Explosives and Information Circular 7380 on Safe Storage Handling and Use of Commercial Explosives 17. Spontaneous ignition precau- tions should be taken in connection with stor- age of materials which may cause spontaneous ignition Rooms in which there may be explo- sive concentrations of dust gases or vapors should have explosion electrical fixtures and equipment in accordance with the provi- sions of the National Electrical Code relating to hazardous locations 18. Electrical equipment following general information should be used in conjunc- tion with the National Electrical Safety Code National Bureau of Standards Handbook H30 a General protection practicable transformers control boards and other accessories should be placed in special rooms to which only authorized persons have access If the use of a separate room is not feasible en- closures should be built around those parts of electrical equipment having exposed conduc- tors Enclosures made of metal should be effec- tively grounded Warning signs should be displayed near exposed carrying parts and in specially hazardous areas such as high voltage installations Signs should be large enough to be read easily and they should be so placed as to be visible from all approaches to the danger zones They should be displayed in as many languages as needed Suitable insulating mats or platforms of substantial construction and providing good footing shall be placed on floors and if necessary on the frames of the machines having exposed live parts of more than 150 volts to ground so that the operator or persons in the vicinity cannot readily touch such parts unless standing on the mats platforms or insulating floors b Grounding Fixed equipment or appliances having exposed metal frames should be grounded under any of the following condi- tions 1 If operated at more than 150 volts to ground regardless of location 2 If located where exposed grounded surfaces as plumbing fixtures or conductive floor and wall can be reached by a person while touching the metal parts of equipment 3 If located in hazardous areas The grounding of portable equipment should follow that of fixed equipment except 1 electrically heated appliances exempted by administrative authority and 2 motors if positively guarded under all conditions It is recommend- ed however that motors always be grounded c Ground connections connec- tions should be of copper and the combined re- sistance of the grounded wire and the connection with the ground should not exceed 3 ohms for waterpipe connections nor 25 ohms for artificial grounds The actual ground circuit resistance should be kept as far as possible below the maximum permissible limits Where a grounding wire is exposed to mechanical injury it should be protected by conduit connected at both ends to the grounding wire or by other substantial enclosure If the enclosure is of metal it also should be grounded d Transformers should preferably be located outside of buildings and surrounded by an enclosure of grounded metal at least 8 feet high If a building wall forms a quickly col- part of such an enclosure all windows in the wall should be screened or barred Transformers inside buildings should be in ventilated fireproof vaults having placed raised sills across the doorways to prevent the of leaking oil Floors and floor drains escape that oil will should be so arranged lect in drainage or storage systems provided Air vents should be so designed for the purpose automatically in case of fire It may as to close for introduc- be advisable to provide equipment fire extinguishing material into transform- ing Doors to transformer enclo- er cases or vaults or vaults should be kept securely locked asunrdesonly authorized personnel should be per- When the switch cannot be locked out espe- in cially if it is located an open work area it is advisable to station a watchman near the switch to see that it is not disturbed while the work is in progress Warnings should be given to all operators affected before opening a circuit and again before closing the circuit after the job is completed 19. Tools Each employer should heed the safe condition of the tools used by his em- ployees whether furnished by him or by them and make every reasonable effort to insure that such tools are suited both by safe design and construction to the work to be done b Each employer should institute and maintain a definite system of tool inspection mitted to enter such areas e Plant wiritnhge ANlatliowniarlinEglecsthroiucladl bCeodien accordance with and also with local codes or requirements f current devices safe curcarrying capacity of conductors is determined by their size the material of which they are made and the manner in which they are installed If forced to carry more than the maximum safe load or limited as to heat dissipation excessive heating results Fuses or other current devices should be installed in every circuit and they should be of a size and type that will interrupt the current flow when it exceeds the capacity of the conductor Protection of this kind both for personnel and for equipment is one of the important features of any electrical installation g Drop and extension Extension cords should be of a type approved by the Underwriters Laboratories Inc. and they should be labeled to show that they meet all requirements of the National Electrical Code They should be inspected regularly Kinking or excessive bending of the cords should be avoided to prevent breaking of the wire strands Broken strands may pierce the insulating and repair suited to conditions c Tools in disrepair should not be used d All powered tools which might cause injury through continued operation should the operator lose his hold should be equipped with the called dead man type of control or the equivalent whereby the power is automatically cut off when the operator loses his hold e Portable electric power tools should be equipped with ground wires to maintain at all times an effective ground on the noncurrent carrying parts of the tool C. FIRE PREVENTION AND PROTECTION 1. Building egress .- All buildings in which persons are employed or are assembled for any purpose should be provided with safe and proper ways of egress or means of escape from fire sufficient for the use of all persons accommodated or assembled within the build- ing Such ways of egress should be kept free from obstructions and in good repair and ready for use at all times The provisions of the American Standard Building Exits Code A9.1 should be followed b All buildings or establishments of two or more stories in height should be provided covering and become shock or circuit hazards with more than one way of egress or escape from fire said ways of egress being so located h Lamp fixtures and equipment For locations where there are flammable gases or dusts lamps should be installed only in fixtures especially designed to prevent lamp breakage and to prevent ignition of the flammable material Equipment should be of explosion design i Maintenance should always be tagged or locked in the open position before starting work If a lock is used for which keys are available to other members of the organi- zation the switch should also be tagged in such a way as to identify the individual authorized to remove the lock If two or more employees are working independently on the same circuit affix his own lock or tag to the esawcihtcshhould and in such positions as to prevent the trapping of persons in the building Such ways of egress may lead to adequately constructed and properly maintained fire escapes on the outside of the building or to inside stairways provided with proper hand rails and satisfactory for emergency use Such stairways should preferably be fire resistant and lead directly to the outside at grade level All exit doors should swing in the direction of exit and should open in such manner as not to obstruct passageways or corridors used as way of egress and escape from fire or panic No chairs or seats fixtures chutes materials or equipment should block or in any way jeopardize the use of ways and means provided for egress All exit doors and windows used as means of egress in case of fire or panic should be so arranged as to be always readily opened from the inside Locks on doors and windows if provided should not require the use of a key to operate from the inside c All exits or means of egress as above specified should be plainly designated or marked eral Government have developed codes of similar excellence which nevertheless vary in some details from the ASME Code Insurance com- panies which insure steam boilers against explosion generally apply the provisions of the ASME Code _ by conspicuous signs or lights to identify the means of escape Directional signs should be provided where needed Ladders are not accept- ; able as fire escapes 2 Operated by personnel whose competence entitles them to hold certificates granted by licensing authorities set up for the purpose 3 Regularly inspected by competent in- 2. Fire extinguishing equipment Equip- ment suitable to the conditions and hazards in- spection personnel b Heating boilers and miscellaneous small volved for the extinguishment of fires should be boilers State boiler codes exempt boilers provided and maintained in an effective operat- intended for low pressure usually below 15 ing condition The importance of a systematic pounds The violence with which even the inspection of these devices is emphasized This smallest boiler can explode should not be under- equipment includes built equipment such as estimated Every vessel however small in automatic sprinkler CO and steam lines Also which water is heated can if its normal outlet operated equipment such as hose and is closed or plugged up become in fact a high- portable fire extinguishers sand pails water pressure steam generator and if its strength barrels and pails and other equipment effec- is exceeded will explode destructively The re- tively located mounted and maintained curring explosions of such pressure devices b Aisles leading to and areas in front of all extinguishing equipment should be open at all times free and clear and unobstructed by materials stock and equipment of any kind c Classes of fires and recommended extin- indicate a too widespread failure to keep this simple fact in mind Therefore the accident preventionist should take careful account of every fired water or steam vessel and make sure that guishing equipment Listed below are various classes of fires and the extinguishing equipment which is recommended in each case 1 It is of safe construction for the pres- sures involved 2 It has adequate means of limitation of 1 Class A Fires in ordinary combustible materials where the quenching and cooling effects of quantities of water or solutions pressure such as a A safety valve of adequate capacity b A disk or diaphragm that will fracture containing large percentages of water are of at a predetermined pressure first importance 3 It is regularly inspected competently Recommended extinguishing equipment operated and properly maintained Soda and acid pump tank extinguishers or c Steam cookers digesters glue pots etc. se water barrels and buckets All pressure vessels to which steam is supplied 2 Class B Fires in flammable liquids greases etc. where blanketing effect is essential from an outside source should be designed insofar as it is practical for the maximum line pres- sure Most of them are not and on such vessels Recommended extinguishing equipment.Foam carbon tetrachloride CO dry powder pressure extinguishers sand buckets and scoops 3 Class C Fire in electrical equipment where the use of nonconducting extinguishing agent is of first importance Recommended extinguishing equipment Carbon tetrachloride CO dry powder pressure extinguishers it is vitally important to install in addition to the necessary reducing valve a safety valve on the vessel itself or on the line between it and the pressure reducer There should be no means of cutting off or bypassing this safety valve Inspection and adequate maintenance of the vessel including regular testing of the safety valve are vital 2. Compressed air machinery and equipment the detailed operation of this type of equipment refer to American Standard D. PRESSURE VESSELS Safety Code For Compressed Air Machinery 1. Fired pressure vessels- Steam boil- The safeguarding of power boilers has been developed to such a high standard that it can be truly said that boiler explosions are entirely preventable provided that boilers are and Equipment however the general rules listed below should be applied a Compressors If a operated air compressor is driven by other than an electric motor including those driven by serieswound current motors a speed gover- 1 Constructed and installed in accordance with the Power Boiler Code of the American nor should be installed on the prime mover to prevent racing of the latter from any cause Society of Mechanical Engineers or equivalent standards Various States cities and the Fed- Such a speed governor should act independently of the unloader on the compressor 10 2 If the air compressor is engine or tur- bine driven an auxiliary control to the gover- nor should be installed to prevent racing when the unloader operates 3 Every air compressor should be equipped with an automatic mechanism so ar- ranged that the compressor will automatically stop its compressing operation before the discharge pressure exceeds the maximum work- on ing pressure allowable under this code the weakest portion of the system to which the compressor is connected 4 If this automatic mechanism is electri- cally operated the actuating device should be so designed and constructed that the electrical contact or contacts cannot lock or fuse in a position that will cause the compressor to continue its compressing operation b Switches and other electrical apparatus the compressor is driven by an electric motor all electrical switches and other electri- cal apparatus should be guarded as required by the National Electrical Safety Code and the National Electrical Fire Code c Belt pulley gear and shaft guards All belts pulleys gears flywheels and shafts should be guarded as outlined in Part II E of these standards d Lubrication Specific requirements for lubricating oils are intentionally omitted from these standards In the operation of air com- pressors many of the troubles experienced can be traced to the use of a poor or unsuitable grade of oil in the air cylinders The importance of good air cylinder oil is generally recognized by the leading manufacturers of equip- ment and of lubricants and it is therefore sug- gested that their recommendations be followed Air compressor cylinders should be lubricated by means of visible forced lubri- cators Only enough oil should be used to furnish satisfactory lubrication in order to avoid carryover to intercoolers aftercoolers receivers and other parts of the system e Cooling water cooling is used a visible indication of water flow should be pro- vided f Operation and maintenance Compressor valves should be inspected checked for broken springs and tested for tightness frequently and at regular intervals Leaky valves should be made tight by repair or replacement Accumulations of carbon or other foreign mat- ter should be removed 2 Unloaders and governor controls on air compressors should be inspected at frequent and regular intervals and should be maintained in good working condition Where emergency overspeed stops are installed such devices should be tested at regular intervals to insure their operation within safe limits of overspeed 3 If the compressor is steam driven the - throttle valve should be closed and tagged and the cylinder drain cocks should be opened before starting repairs or other work on the com- pressor If 4 line the compressor is motor driven the line switch supplying the motor should be opened and tagged or locked before starting repairs or other work on the compressor 5 Under no circumstances should kero- sene gasoline or other flammable solvents be introduced into the compressor cylinders the piping or the receiver Soapy water or any suitable toxic nonflammable solution may be used for cleaning such portions of the system g Aftercoolers Aftercoolers should be designed to withstand safely the maximum pressure in the air discharge piping 2 The advantages to be gained by using aftercoolers are of sufficient importance to warrant consideration of such equipment on at least new installations Aftercoolers reduce the temperature of the air discharged by the compressor to a point at which most of the mois- ture and oil vapor condenses and can be removed 3 The removal of the moisture tends to prevent water hammer in the air lines The condensation of oil vapors tends to prevent their being carried over to pipe lines receivers and other parts of the systems 4 Where pipelines and receivers have become coated with oil because of improper lubrication of the compressor explosive mixtures of air and oil vapor may be formed at high temperatures Consequently overheating should be avoided and oil accumulation should be immedi- ately removed 5 The use of aftercoolers tends to maintain more nearly uniform air temperatures on the discharge side of the system thereby minimizing the strains resulting from alternate expansion and contraction of pipelines h Piping - 1 Installation - Piping should meet the requirements of the American Standard Code for Pressure Piping In its installation adequate provision should be made for expansion and contraction and to counteract pulsation and vibration Steam and air piping should be equipped with adequate traps or other means for removing liquid from the lines Air discharge piping should be so installed that pockets where oil may accumulate are avoided 2 Insulation piping should be adequately insulated where it is exposed to contact 3 Compressor air Provision should be made to prevent drawing air containing flammable or toxic gases vapors or dusts into the compressor and to prevent steam water or waste of any sort from being blown 11 or drawn into the compressor intake No valve should be installed in the air intake pipe to an air compressor 4 discharge piping discharge piping from the compressor to the air receiver should be at least as large as the discharge opening on the air compressor Because the discharge pipe becomes hot no wood or other flammable material should be permitted to remain in contact with it i Valves Stop valves in the air line between the compressor and the air receiver are not recommended In every case where a stop valve is so installed one or more springloaded safety valves should be installed between the compressor and the stop valve The total capacity of such safety valves should be sufficient to limit the pressure in the air discharge piping to 10 per cent above the relieving pressure of the safety valves on the air receiver 2 Any stop valve which may be installed in the air discharge piping should be so located that it can be inspected and cleaned at definite regular intervals Stop valves should preferably be of the gate type and not of the globe type If a globe valve is used it shall be so installed that the pressure is under the seat and that the valve will not trap condensation 3 Every driven air compressor should be provided with a manually operable throttle valve in the steam supply line in a readily accessible location 4 stop valve should be installed between the air receiver and each piece of stationary utilization equipment at a point convenient to the operator thereof 5 A stop valve should be installed at each outlet to which an air hose may be attached j Receivers Construction Air re- ceivers should be constructed in accordance with the 1937 Edition of the A.S.M.E. Code for Unfired Pressure Vessels.2 The operating pressure should be based on a factor of safety of not less than 5. Inspection openings should be provided in all air receivers 18 inches or more in diameter 2 Installation receivers should be so installed that all drains handholes and manholes therein are easily accessible Air receiv_ ers should be supported with sufficient clearance to permit a complete external inspection and to avoid corrosion of external surfaces Under no circumstances should an air receiver be buried underground or located in an inaccessible place The receiver should be located as close to the compressor or aftercooler as is pos- sible in order to keep the discharge pipe short The receiver should be located in a cool place to facilitate the condensation of moisture and oil vapors 2 Published by the American Society of Mechanical Engineers 29 W. 39th St. New York City 3 Drains and traps drain pipe and valve should be installed at the lowest point of every air receiver to provide for the removal of accumulated oil and water Adequate automatic traps may be installed in addition to drain valves The drain valve on the air re- ceiver should be opened and the receiver com- pletely drained frequently and at such inter- vals as to prevent the accumulation of excess amounts of liquid in the receiver 4 Gages and valves.Every air receiver should be equipped with an indicating pressure gage so located as to be readily visible and with one or more spring safety valves The total relieving capacity of such safety valves should be such as to prevent pressure in the receiver from exceeding the maximum allowable working pressure of the receiver by more than 10 percent No valve of any type should be placed between the air receiver and its safety valve or valves k Working space the location of compressors and related equipment provision should be made for safe access to all parts of the equipment for operation maintenance and repairs 1 Aisles space should be adequate should be independent of work and storage areas and should be defined by floor markings m Safety valves All safety valves used should be constructed installed and main- tained in accordance with the A.S.M.E. Code for Unfired Pressure Vessels 2 Safety appliances such as safety valves indicating devices and controlling devices should be constructed located and installed so that they cannot be readily rendered inoperative by any means including the elements 3 All safety valves should be tested frequently and at regular intervals to determine whether they are in good operating condition E. MACHINERY GUARDING 1. Railings and toeboards standard railings and toeboards are specified in this manual they should conform to the following specifications a Railings should be 42 inches in height except where otherwise specified and should be equipped with toeboards unless the space be- tween the lower rail and floor is filled with material as specified in b b They should be of substantial construc- tion should be permanently fastened in place and should be smooth and free from protruding nails bolts and splinters An intermediate rail should be provided between the top rail and the floor unless this space is filled with substantial wire mesh expanded metal or other suitable material c If constructed of pipe the inside diame- 12 ter of the pipe should not be less than 1-1 inich nch d If constructed of metal shapes or bars each part should have a cross section at least equal in strength to that of a 1-1 by 16- inch angle iron should e If constructed of wood the posts should not be smaller than the sizes commercially known as 2- by inch or 3- by inch The top rail should be at least as large as the size known as 2- by inch The intermediate rail should not be smaller than the size commer- cially known as 1- by inch f Posts and uprights should be spaced not more than 8 feet apart g Toeboards should be at least 5-1 inches in height and be constructed of wood metal metal grill with openings not exceeding 1 inch or other suitable material h Intermediate rails and toeboards and top rails which are attached to the side of the posts should be placed on the side of the posts away from the engine belt floor opening etc. to be guarded so that any blow or pressure against them will be taken up by the posts instead of tending to push the rails away from the posts 2. Guards a If guards are made of wire mesh perforated or expanded metal crossed strips or bars of wood or metal etc. the width or diameter of the holes should not . exceed 2 inches If parallel strips or bars of wood or metal are used the space between them should not exceed 1 inch There should be no openings more than 1/2 inch in width or diameter within 4 inches of any gear belt pulley or flywheel or other dangerous moving part Wood slats should be smooth and free from splinters and the holes in perforated or expanded metal should be free from sharp cut- ting edges b The supporting frames should be of substantial construction such as angle iron varying from 1 by 1 by 1/8 inch to 1-1 by 3/16 inch or iron pipe with inside diameter varying from 3/4 inch to 1-1 inch according to the weight of the filling material the size of the panels and the exposure of the guard to collision with trucks etc. Any panel which measures more than 42 inches in both width and length should be substantially supported across its narrowest dimension at intervals of not more than 42 inches c The filling material should be bolted riveted or otherwise securely attached to the frame in such a manner that no sharp points or edges will be exposed Bolts should be at least 3/16 inch in diameter and should be spaced not more than 10 inches apart Flat bars or strips used for clamps should not be smaller than 3/4 by 1/8 inch if of iron or 1 by 1 inch if of wood Perforated or sheet metal may be spotwelded to angle iron frames d The thickness of material used for guards should not be less than is specified in the following table Material Clearance from moving part at all points Largest mesh Opening allowable C Minimum gauge U. S. Standard or thickness Woven Expanded metal ..c:sccsssscescecceecee inches Under 4 inchesinches crosses 4-15 inches ..........-... inches Under 4 inches .......... 4-15 inches ........0.. i nch sees # 16 2 inches 0... | 12 j iinncch h ooo. 18 2 inches ....-..--J 13 Perforated metal ere ........0..:..c:eceeee _ Under 4 inches pananneatl 4-15 inches oo... inch ee: oer 2 inches 0.00. - 20 14 Sheet metal ccccccccccccccccccccsssssssvsssesseneeeeee Wood or metal strip crossed .................- Under 4 inches 2.0.00...) occ ece eee eseeeeesee eee 4-15 inches ...........,,[ ccvevecessseseetesstesesesseeceees 22 22 Under 4 inches ....... : 4-15 inches ............... inch wrereeerenrcenee 2 inches o.........-. Wood % inch metal 16 Wood 4 inch metal 16 Wood or metal strip not crossed .......... Under 4 inches a. | 4-15 inches ......... 12 inch width .......... 1 inch width ........... Wood % inch metal 16 Wood inch metal 16 Solid wood,,sevssestsanneesrennescesescsecenniaaesesece| vecucusatsussestanaesserecssssessece | coeseeseeeeaetseecieseeetenseeess ' aasestessessenseneeseseenserees ceneeareanersnsea 1 If plywood is used it should be not less than 3 inch thick and not less than 3 ply 13 e Guards should be securely and permanently fastened in place except as otherwise specifically provided 3. Belts pulleys etc All vertical and inclined belts should be completely enclosed or effectively guarded However belts that 1 inch or less in width need be guarded are only to 6 inches from the nip point b All belts regardless of shape size epnocsliotsieodn oorr refufnencitinvgelsypegeudarsdhoeudld be completely 4. Vertical and inclined belts If the guard is within 4 inches of a belt or should extend from the floor pulley it to a height of at least 6 feetorIfpltahtefogrumarldeveils within 15 inches but not within 4 inches of the belt or pulley it should extend from the floor or platform level to a height of at least 5 feet except in each case as follows 1 If any part of a pulley is more than 5 feet but less than 7 feet above the floor form level the guard should extend or platto the of the pulley but need not exceed top 7 feet above the floor a height of or also applies to clutches platform level This 2 If the top of any pulley is not more than 5 feet above the floor the guard need not extend above a point midway between the of the pulley and a height of 5 feet top provided that in no case should it extend less than 42 inches above the floor unless it as well as all sides of the belt covers and the top which case there should be pulley in to height no requirement as 3 If it is an overhead belt the guard be a basket or box suspended from may above and extending across the bottom of the pulley and all around the pulley to a height of 6 feet ex- height when the guard should extend to the top need not exceed 7 feet b Where no pulley hazard is involved a standard railing placed not less than 15 inches or more than 20 inches from the belt measured horizontally be from the top of the railing will considered a sufficient guard b Where the upper run of the belt is more than 7 feet above the floor or platform level and the lower run is within 7 feet of the floor the pulleys should be guarded on sides and outer face to a height of 7 feet above the floor platform level and the belt or two pulleys should extend agtualredastbet15weeinnchtehse above the lower run but need not exceed a maximum of 7 feet and should be a minimum of 42 inches above the floor or platform level unless completely enclosed Unless the guards extend across the inner face of each pulley to a height of seven feet the guard for the lower run of the belt should be carried to the height as the pulley guards at all points same within 15 inches horizontally from the inner face of either pulley c Where pulleys are so located and of such dimensions as to permit passage between the upper and lower runs of the belt the space be- tween the pulleys should be completely barred or should be provided with a stantially guarded on sides andptaospsaagnedwbaoytstuobm- 6. Cone pulleys and belts Cone pul- ley belts more than 2-1 inches in width should be equipped with mechanical belt shift- ers and all cone pulley belts should be guarded to a point 3 inches above the nipping point of the belt and pulley and not less than 3 feet 6 inches from the floor or platform where part of the lower cone is less than 3 feet any above the floor or platform level b Where both upper and lower within 7 feet of the floor or cones arc for example on some vertical pdlraitllfoprrmeslseevselanads other machines and for which conditions such that mechanical belt shifters are are not re- quired and none are furnished the belt and cone pulleys should be guarded as specified in Part II E 2 above with a hinged self closing section to permit shifting c All belts regardless of width should be provided with belt shifters when joined to- gether with a metallic or other form of fastener which by construction or wear will constitute a hazard c If the belt is inclined the height of the guard or distance of the guard or railing from the belt should be such that the vertical clear- ance between the floor and the lower run of the belt at any point outside of the guard or ing should not be less than 6 feet 6 rail- inches 5. Horizontal belts Where both of the belt are within 7 feet of the floor runs ifnocrhmesleavbeolvethethgeuard should extend at loerasptla1t5- 7 feet above the upper run floor In or to a height of no case should the guard extend less than 42 inches above the floor except that if it covers the top as well all sides of the belt and pulley there should as be no requirement as to height a 7. Machine control Every machine should be equipped with a loose pulley clutch switch or other adequate means readily accessible for the purpose of stopping the machine quickly b Machines on which two or more ; work should be equipped with persons one or more con- trols so located that more than one of these persons can quickly disconnect the machine from the source of power c Machines operated from a number of different places should be provided with read- ily accessible means for shutting off the power and means of locking controls to protect men working on the machines against unexpected starting 14 a= 8. Belt shifters Every set of tight and loose pulleys should be equipped with a permanent belt shifter so located as to be within easy reach of the operator The belt shifter should be so constructed as to make it impos- sible for the belt to creep from the loose pulley to the tight pulley b Every belt shifter should be equipped with an interlocking device which will prevent accidental shifting shifters belt c Where overhead shifters are not located directly over a machine or bench the shifting lever should be cut off 6 feet 6 inches above floor level 9. Location on shafting a Every pulley near a shaft hanger shaft bearing or other fixed object should be placed so as to al- low a side clearance at least 1/2 inch greater than the width of the belt between the pulley and the nearest part of such shaft hanger shaft bearing or other fixed object or a guard should be placed adjacent to the pulley to prevent the belt from running off on the side next to the shaft hanger shaft bearing or other fixed object b Where pulleys must be closer together on the shaft than the width of the wider belt plus 1/2 inch the pulleys should be guarded so that the belt on either pulley cannot run off between the pulleys 10. Gears gears should be solidly en- closed except that gears without spokes or holes in the web may be guarded by a band guard with flanges extending beyond the root of the teeth 11. Keys and keyseats Every projecting key in revolving shafting where exposed to contact should be cut off or enclosed b Every keyseat in revolving shafting where exposed to contact should be filled or enclosed 12. Flywheels and shafting Flywheel Flywheels located so that any part is six 6 feet or less above the floor or platform should be guarded in one of the following ways 1 With a standard railing railing must be placed not less than six 6 inches nor more than twenty 20 inches from the wheel provided that it should be not less than fifteen 15 inches from the spokes of wheel or projections If wheel extends into pit or within two 2 inches of the floor a standard toeboard should be installed If passage over jour- nal or bearing is necessary the passageway should be provided with a standard railing and toeboard 2 With an enclosure of sheet perforated or expanded metal or woven When such guard is placed less than six 6 inches from wheel it should be not less than six 6 feet high except if flywheel is less than six 6 feet high the guard should be not less than the height of the wheel from the floor In no case should guard be less than three 3 feet six 6 inches high unless wheel is completely enclosed including the top Where clearance of guard from flywheel at any point is under four 4 inches the largest mesh or opening allowable should not be more than half 1/2 inch Where such clearance is from four 4 to fifteen 15 inches largest mesh or opening allowable should not be greater than two 2 inches 3 Flywheels with smooth rims five 5 feet or less in diameter other than wheels having solid web centers where the preceding methods cannot be applied should be provided with a disc having a smooth surface and edge attached to the flywheel in such a manner as to cover the spokes of the wheel on the exposed side The disc may be four 4 inches smaller in radius than the radius of the inner surface of the wheel if it is desired to provide space for bar in turning over the wheel Keys and other dangerous projections not covered by disc should be cut off or covered 4 An adjustable guard may be used where it is necessary to start engine or for making adjustments 5 A slot opening for jack bar will be per- mitted 6 Spokes of pulleys balance wheels or flywheels other than on a prime mover the bottom of which is six 6 feet or less above the floor or other working level should be protected by filling in the spokes or by guarding as required for belts b Shafting exposed parts of transmission shafting six 6 feet or less from floor or working platform should be protected by a stationary casing enclosing shafting completely Horizontal shafting may be guarded by a trough enclosing sides and top or sides and bottom of shafting as location requires Shafting under bench machines should be enclosed by a stationary casing or by a trough at sides and top or sides and bottom as location requires The sides of the trough should come within at least 6 inches of the underside of the table or if shafting is located near floor within 6 inches of floor In every case the sides of trough should extend at least 2 inches below or above the shafting as the case may be Revolving shafting and spindles forming part of and integral with individual machines where part creates a hazard should be en- closed or covered 13. Presses Preferred guarding meth- Protection from the dies of every press except metal presses should be provided by means of the following 1 Complete enclosure or 2 Full automatic feed or 3 Semiautomatic feed with ram enclosure or 4 Limited opening 3/8 inches between dies The maximum width of opening in the enclosure or between the enclosure and working surface shall be not greater than shown in the following table Distance of opening from nip point inches Maximum width of opening inches 0 2to 3to 2 cr: 3 cece lec ccceeeensccesccacetsescecavsnseateneseees 5 eee cccccccccecacsecescseseataeseseseneeeess 5to 6 eee ceccccsccesesssecsessatateceecccccseeeseess 6 to cr 7to 8 cece ccccccecesecetessecseseteseesecccoces 3/8 1/2 58 % 7/8 1 b Alternative guarding methods in case none of the methods in a above can be applied then a device which will reasonably prevent injury by contact with dies should be installed as follows 1 A hand tripping device for each person engaged in the operation of a single press so designed and arranged as to prevent tying wedging or otherwise securing one handle or button and operating the press with one hand only or 2 An interlocking gate guard operated by the tripping device of the press which interposes a barrier on the front and sides of the ram before the plunger descends and will not permit the press to operate until the hand or hands of the operator have been removed from the danger zone or 3 A sweep or gate guard with the sweep arm or gate interconnected to the ram and so designed and constructed as to sweep the hands of the operator from the die zone as the ram descends with each single sweep arm provided with a flag or barrier attached thereto so that the operator cannot reach behind the sweep or 4 A pull protective device attached to the operator's hands or arms and connected to the ram or outer slide of the press in such a way that the operator's hands or fingers will be withdrawn from the danger zone as the ram or outer slide descends and designed so that where the open distance between the top of the work and the lower extremity of the punch is less than 2 inches that the multiplying action of this guard should be such that the hands will be withdrawn a safe distance from the nip point during the first quarter of the stroke c Special hand tools should be accepted only as an accessory to the guards listed herein and not as a substitute for any guard d Guards which are attached to the ram and which move downward so that the opera- tor's hand or fingers may be caught between the gate and lower die should not be used e Where the speed of the ram is so slow that the operator might beat the ram on the down stroke after the press has been tripped no device should be used which permits the insertion of the hands until the completion of the downward stroke without stopping the ram f Every hand power press should be equipped with 1 An arrangement which disconnects the treadle or operated lever from the clutch mechanism after each stroke or 2 A device that will within its own ac- tion automatically lock the clutch mechanism into place so that the press cannot make a sec- ond stroke until the treadle or hand lever is again pressed to its lowest position or 3 By some other method which will accomplish the result outlined above unless the danger zone protection is such that the guard remains in its protective position during the second stroke of the press g Platen presses presses with or without mechanical power should be provided with one of the following 1 An automatic feed which does not require the operator's hand to be placed between the platen and bed or an automatic stop which will prevent the platen from closing if the hand or hands of the operator are caught between the platen and the bed or 2 A guard gate or sweep motion which will throw the operator's hands out of the way as the press closes If of the type which lifts the hands out of the danger zone the guard should rise at least 4 inches above the platen as the press closes and should descend by gravity or by mechanical means The guard should be arranged so that it will prevent a shear between the guard and the top of the platen or 3 Any other device that will prevent the platen from fully closing before the operator's hands are removed from between the platen and the bed 14. Abrasive wheels following stan- dards for the operation of abrasive wheels should be supplemented by the American Standard Safety Code for the Use Care and Protection of Abrasive Wheels to insure that full safety measures are taken in their opera- tion a Handling grinding wheels are breakable and some are very fragile Great care should be exercised in handling and storage to prevent damage which might cause a wheel to fly apart when brought up to speed The fol- lowing rules which are based on experience should always be observed , 1 Handle wheels carefully to prevent dropping or bumping 2 Do not roll wheels hoop fashio.n 3 Use trucks or suitable conveyors which will will provide proper support for all transporta- 3 Exemption to 2 and 3 Where it is impractical to comply with 2 and 3 because of large size of wheel danger of damage when rolling the wheel will be minimized if floor is smooth clean and free from obstructions The use of a strip of rubber or cork matting will further reduce the danger 16 tion of wheels which cannot be carried by hand.3 4 Stack wheels carefully on trucks Do not pile heavy castings or tools on top of them nor permit wheels to topple over b Storage racks bins or drawers should be provided to accommodate the various types of wheels used Wheel storage rooms should not be subject to extreme temperatures and should always be kept dry c Inspection Immediately after unpack- ing all wheels should be closely inspected to make sure that they have not been injured in transit or otherwise As an added precaution wheels should be tapped gently while suspended with a light implement such as the handle of a screw driver for light wheels or a wooden mallet for heavier wheels If they sound cracked they should not be used Wheels must be dry and free from sawdust when applying the test otherwise the sound will be deadened It should also be noted that organic bonded wheels do not emit the same clear metallic ring as do vitrified and silicate wheels d Rigidity Grinding machines should be sufficiently heavy and rigid as to minimize vibration Where practical the machines should be securely mounted on substantial floors benches foundations or other adequate structures e Guards Every stationary abrasive wheel and portable wheels used in stationary position should be equipped with guards of the hood type strong enough to withstand the shock of a bursting wheel A hood type or band guard strong enough to withstand the shock of a bursting wheel should be used on every portable wheel where the operation and the nature of the work will permit f Spindle spindle and nut and flange projection if any should be guarded g Mountings and fastenings should be so mounted as to maintain proper alignment with the wheels and the strength of the fastenings should exceed the strength of the hood h Dust exhaust provisions on machines used for dry grinding and other operations where dust is produced should have provisions made for connection to an exhaust system For detailed recommendations reference is made to American Standard for Grinding Polishing and Buffing Equipment Sanitation Z43 i Exposures permitted Bench and floor stands The maximum angular exposure of the grinding wheel periphery and sides for hoods used on machines known as bench and floor stands should not exceed 90 or fourth of the periphery This exposure should begin at a point not more than 65 above the hori- zontal plane of the wheel spindle Wherever the nature of the work requires contact with the wheel below the horizontal plane of the spindle the exposure should not exceed 125 This exposure should begin at a point not more than 65 above and extend to a point not more than 60 below the horizontal plane of the wheel spindle 2 Cylindrical grinders The maximum angular exposure of the grinding wheel periphery and sides for hoods used on cylindrical grinding machines should not exceed 180 This exposure should begin at a point not more than 65 above the horizontal plane of the wheel spindle 3 Surface grinders and cutting machines -The maximum angular exposure of the grinding wheel periphery and sides for hoods used on cutting machines and on surface grinding machines which employ the wheel periphery should not exceed 150 This exposure should begin at a point not less than 15 below the horizontal plane of the wheel spindle 4 Swing frame and portable grinders.The maximum angular exposure of the grinding wheel periphery and sides for hoods used on machines known as swing frame and portable grinding machines should not exceed 180 and the top half of the wheel should be pro- tected at all times 5 Top grinding operations where the work is ground on the top of the wheel the exposure of the grinding wheel periphery should be as small as practicable with a maxi- mum exposure of 60 j Exposure adjustment of the type described in 1 and 2 under Expo- sure Permitted where the operator stands in front of the opening should be constructed so that the peripheral protecting member can be adjusted to the constantly decreasing diameter of the wheel The maximum angular exposure above the horizontal plane of the wheel spindle as specified in 1 and 2 should never be exceeded and the distance between the wheel periphery and the adjustable tongue or the end of the peripheral member at the top should never exceed 1/4 inch k Work Work rests should be kept adjusted close to the wheel with a maximum distance of 1/8 inch to prevent the work from being caught between the wheel and the rest The work rest should be securely clamped after each adjustment The adjustment should not be made while the wheel is in motion 15. Miscellaneous machine guarding Revolving oscillating or reciprocating parts of engines and other machines 1 Every projecting set screw in moving parts where exposed to contact should be guarded 2 Cranks or crank discs crank shafts connecting rods where exposed to contact should be guarded 17 3 Eccentrics and cams where exposed to contact should be guarded 4 Machine parts having a reciprocating or oscillating motion such that a shearing or crushing hazard is created should be guarded 5 Any moving part of a machine which at any time leaves a space of less than 18 inches between it and any fixed object not a part of the machine or between it and a moving or stationary part of any other machin~ should be guarded b Oiling devices machines lubricat- ed while in motion and having lubricating de- vices so located as to make it hazardous to reach them should be equipped with an automatic oiling device or some equally efficient means to protect the oiler Machines shut down for oiling or maintenance should be marked locked or otherwise protected so as to prevent starting the machine while such work is in progress c Projecting parts on shafts projecting part on a revolving shaft such as a collar clamp pin coupling oiling device etc. where exposed to contact which should include exposure while oiling machinery in motion should be guarded d Revolving stock revolving stock projecting from machines should be guarded by pipe enclosure or other means to prevent contact with the stock e Noise reduction is desirable to re- duce to the minimum the noise incident to the operation of machines especially where there are a number placed close to each other 16. Fans blades of every fan open to contact should be guarded in accordance with Part II E of these standards except that fans more than seven feet above the floor or work- ing level need not be guarded providing the blades cease to revolve before any work of a character which would expose any person to contact with such fan is permitted This standard also applies to the ordinary office fan 17. Revolving drums and cylinders Revolving barrels drum or other containers where exposed to contact should be guarded by an enclosure or standard guard rail in accord- ance with Part II E of these standards b Tanning drums where exposed to contact should be guarded by an enclosure built in accordance with guarding as specified under Part II E to a height of 6 feet c Every drum or other revolving container which must be loaded or unloaded should be equipped with a brake or lock which will enable the operator to lock the drum while loading or unloading it 18. Counterweights tension weights and springs Every counterweight where exposed to contact should be enclosed or equipped with a safety chain that will prevent the weight from falling to a distance of less than 7 feet from the floor or working level b Every tension weight exposed to contact should be enclosed or securely fastened to the tension bar c All springs should be guarded or otherwise equipped to eliminate any hazard due to breakage of spring or failure of the mounting 19. Lathes and automatic screw machines -Chucks and face plates should be free from projections and dogs if used should be of the safety type circular in shape with no projections beyond the periphery Chip guards to catch flying chips particularly in the case of high speeds used in the softer metals should be provided Rotating stock in turret lathes and automatic screw machines should be completely enclosed pipe in used long enough to contain the longest stock Suitable shields and oil catchers should be provided to prevent slipperiness from the oil thrown from automatic screw machines a Drill presses All projections on the rotating spindle and as much of the spindle itself as possible should be guarded Spindle drive belts when in range of the operator's head or body should be guarded against both contact and breakage b Drop hammers drop hammer the operation of which requires the hands to be placed between the dies should be provided with a positive stop that will prevent the descent of the hammer until the operator's hands are withdrawn A shield or screen should be provided for every drop hammer except where guarded by location when the operation is such that sparks or scales are liable to be thrown off On every board drop hammer a substantial guard should be provided around the board above the roll to prevent the board falling in case the board breaks or comes loose from the ram c Planers and shapers metal The spaces between the ways of planer frames should be filled in smoothly with heavy sheet metal to eliminate the shear hazard Where clearance from fixed objects is inadequate men may be caught by the stroke of planer or shaper in such cases space to allow for the maximum possible stroke should be railed off in such manner as to give protection without creating a shear hazard between the railing and the planer table or the work carried on it d Metal shears are two main types of metal alligator and squaring The latter may be either power or operated All should be guarded 1 Alligator shears shears are used to cut rods bars strap etc. They are 18 aee arranged to run continuously the material being inserted as the jaw opens In cutting short pieces the operator is likely to get his fingers under the knife Also he may stumble or trip in handling the stock and get caught Many in- juries occur through lack of care in sorting out hard metal which might fly when cut or throw chips from itself or from the knife If fairly uniform material is handled mechanical feed can readily be devised In junk yards however this is not feasible Even in such cases it is usually feasible to guard this machine by running a heavy shaped metal strap horizontally around the moving upper jaw with the lower edge of the strap just far enough above the cutting edge of the fixed jaw to allow the material to be inserted under it 2 Squaring Injuries usually result from the fact that where the operator's foot is on the treadle he is in poor balance with the added fact that the necessary angle set of the knife is likely with thick material or a dull knife to draw the material under it and the operator's hand with it Squaring shears either mechanical foot or hand power and fed by hand shall have the knives substantially guarded This guard may be a fixed barrier set not more than threeeighths 3/8 inch above the table or the material being sheared Automatic clamps shall be acceptable as guards when outs are filled in so that the fingers of the operator cannot enter the danger zone F. WOODWORKING MACHINES 1 Band saw or band Band wheels of band saws or band knives and all parts of the blade should be enclosed or guarded except the part between the guide and table that is necessary for the thickness of the material being cut If a metal guard is used it should be of not less than 20 U. S. Standard Gauge If other material is used the guard should be of equal strength and firmness 2. Band resaw wheels of band re- saws and all portions of the blade should be enclosed or guarded except the portion between the guide and table that is necessary for the thickness of the material being cut If a metal guard is used it should be of not less than No. 20 U. S. Standard Gauge If other material is used the guard should be of equal strength and firmness The feed rolls should be enclosed except such part as may be necessary to feed stock 3. Cork cutter Circular knife type. type. A hood should be provided that will cover the knife at all times to at least the depth of the cutting edge The hood should automatically adjust itself to the thickness of and remain in contact with the material being cut at the point where the stock encounters the knife or it may be a fixed or manually adjusted hood or guard provided the space between the bottom of the guard and the material being machined does not exceed 3/8 inch at any time The exposed parts of the cutter blade under the table should be guarded b Band knife type Band wheels of band knives and all parts of the blade should be enclosed except that part between the guide and the table that is necessary for the thickness of the material being cut If a metal guard is used it should be not less than No. 20 U. S. Standard Gauge If other metal is used it should be of equal strength and firmness 4. Circular rip saws hood should be provided that will cover the saw at all times to at least the depth of the teeth The hood should automatically adjust itself to the thickness of and remain in contact with the material being cut at the point where the stock encounters the saw or it may be a fixed or manually adjusted hood or guard provided the space between the bottom of the guard and the material being cut does not exceed 3/8 inch at any time The hood or other guard should be so designed as to prevent a back or a separate attachment that will prevent a kickback should be provided kickback devices should be effective for all thicknesses of materials that are cut Except when grooving dadoing or rabbeting a spreader should be provided and fastened securely at the rear of saw in alignment with saw blade It should be slightly thinner than the saw kerf and slightly thicker than the saw disc The exposed part of the saw blade under the table should be guarded 5. feed circular rip saws hood or guard should be provided that will cover the saw at all times at least to the depth of the teeth The hood or guard need not rest upon the table nor upon the material being cut but should extend to a line not more than 3/8 inch above the plane formed by the bottom of the feed rolls The feed rolls should be enclosed except such part as may be necessary to feed stock A spreader should also be provided and fastened securely at the rear of saw in alignment with saw blade except where a roller wheel is provided back of the saw The spreader should be slightly thinner than the saw kerf and slightly thicker than the saw disc kickback dogs shall be provided in front of the saws The exposed part of the saw blade under the table should be guarded 6. feed band rip Band wheels of feed band rip saws and all portions of the blade should be enclosed or guarded except the portion between the guide and table that is 19 necessary for the thickness of the material be- 11. Jointer or buzz planers cylindrical ing cut If a metal guard is used it should be of not less than No. 20 U. Standard Gauge If other material is used the guard should be of cutting head should be provided A guard which adjusts automatically over the cutting head should be provided All exposed equal strength and firmness The feed rolls should be enclosed except such part as may be necessary to feed stock 7. Circular cross cut saws hood should be provided that will cover the saw at all times at least to the depth of the teeth parts of cutting head should be guarded Where equipped with automatic feed the feeding mechanism should be guarded Where knives are exposed beneath the table they should be guarded 12. Combination woodworking machines.- The hood should automatically adjust itself Each point of operation of any tool should be to the thickness of and remain in contact with the material being cut at the point where the guarded as required for such tool in a separate machine The drive should be so arranged that stock encounters the saw or it may be a fixed or manually adjusted hood or guard provided the space between the bottom of the guard and the material being cut does not exceed inch at any time This rule should not be applied to only the tool in use would be operating 13. Automatic lathes hood or cover should be provided enclosing the cutter blades except at the contact points while the stock is being cut circular cross cut saws with stationary tables where the saw moves forward when cutting 14. Mortising Mortising machines except hollow chisel mortisers should be Circular cross cut saws with stationary tables where the saw moves forward when cut- provided with thumb stops at each side of the chisel ting should have a hood or guard securely fast- 15. Chain mortisers should be ened to the table that will cover the saw in all guarded by enclosure on top positions The hood or guard should extend at 16. Moulders matchers and stickers least two inches in front of the saw teeth when should be guarded with hoods or other enclo- the saw is in its back position sures that should be so arranged and maintained The exposed part of the saw blade under the as to guard effectively all cutting heads and table should be guarded over its entire travel knives 8. Swing cut saws guard should be Feed rolls should be enclosed except such provided that will cover the saw and such guard part as may be necessary to feed stock should adjust itself to the thickness of the stock 17. Panel raisers raisers should be being cut guarded with hoods or other enclosures so ar- There should be an effective device to return ranged and maintained as to guard effectively the saw automatically to the back of the table all cutting heads and knives when released at any point of its travel Feed rolls should be enclosed except such part If a counterweight is used all bolts support- as may be necessary to feed stock ore ing the bar and weight should be provided with 18. Planers should be guarded with cotter pins A bolt should be put through the hoods or other enclosures so arranged and main- a extreme end of the counterweight bar to prevent tained as to guard effectively all cutting heads dropping of weight or where the weight does and knives not enclose the rod a safety chain should be Feed rolls should be enclosed except such part attached to it to prevent dropping as may be necessary to feed stock Limit chains or other positive stops should 19. Drum sanders exposed parts of the be provided to prevent the saw from swinging drum except that portion where the material beyond the front edge of the table comes in contact with the abrasive surfaces 9. Circular resaws hood should be pro- should be guarded vided that will cover the saw at all times except Feed rolls should be enclosed except such part where the material is being cut as may be necessary to feed stock A spreader should also be provided and fas- 20. Shapers The cutting heads of wood tened securely at the rear of saw in alignment shapers should be provided with a guard that with the saw blade except where a roller wheel will prevent the hands of the operator from is provided back of saw The spreader should be coming in contact with the knives This rule slightly thinner than the saw kerf and slightly need not apply when templates are used which thicker than the saw disc will effectively keep the operator's hands away Feed rolls shoulbde enclosed except such part as may be necessary to feed stock from the knives or when shaping stock large enough to accomplish the same purpose kickback dogs across the full width of 21. Tenoners should be provided the table should be provided with hoods or other enclosures so arranged and 10. Portable circular Portable circu- maintained as to guard effectively all cutting lar saws should be provided with a hood that will parts and saws cover the saw teeth at all times except where the material is being cut 22. Wood heel turning machineWos od heel turning machines should be provided with a 20 =~ guard or shield in front of the cutters except so as to prevent undue acceleration Electric while it is necessary to expose a part of the dynamic braking for current and electric cutter while turning stock braking for alternating hoists may be 23. Stave jointers upper half of the used to control the lowering speed rotating head or disc carrying the knives of Each brake should be capable of sustaining stave jointers should be provided with a cover one and half times the rated load over the sides and front geared hoists referred to in these 24. Veneer clipper or Veneer clip- standards should have at least one electrically pers or slicers should be provided with prong guards or shields both in front and back of the knife so arranged that the hands of the opera- operated or mechanical brake On operated cranes with the cage mounted on the bridge girders a foot brake to tor and the man taking away cannot be caught properly retard and stop the motion of the bridge should be capable of retarding at the G. CRANES AND HOISTS rate of 1 foot per second while full load is being carried 1. Overhead trolleys and monorails Every overhead trolley and every monorail crane should be constructed so as to prevent it leaving the track at any point except that where because of necessity for removal trolleys cannot be so constructed an additional guard rail should be installed which will prevent the trolley from falling if it leaves the tracks If removable sections are provided in the guard rail e Lubrication Lubricating devices should be arranged so that they can be reached without danger to the oiler They should also be arranged so that it is not necessary to remove any guards or other parts for lubrication purposes f Collector Collector wires should be guarded when they can be readily contacted 3. Crane footwalks sufficient headroom they should be so arranged that they will drop is available on operated cranes a footwalk into place by gravity immediately upon release should be provided on the drive side along the after removal of trolley entire length of the bridge of all cranes having 2. Cranes recommendations contained the trolley running on the tops of the girders herein should apply to driven overhead To give sufficient access to the opposite side of traveling cranes storage bridges gantry cranes the trolley there should be provided either a and portal cranes and modifications of these footwalk mounted on the trolley a footwalk or types which retain their fundamental features platform in the building or a footwalk on the he a Bumpers bumper should be provided opposite side of the crane at least twice the as at each end of the trolley It should be fastened length of the trolley to the bridge girder or if the rail is prevented If possible footwalks should be located so as RI from sliding lengthwise it may be fastened to to give a headroom of not less than 78 inches 8 the rail A bumper engaging the tread of the Otherwise a headroom of not less than 48 inches wheel should be of a height at least equal to the may be used radius of the wheel Bumpers engaging other parts of the crane are acceptable If it is not possible to provide a headroom of 48 inches or more footwalks should be omitted b Buffers there is more than one trolley on the same bridge girders buffers or cushioning devices should be provided If there is more than one crane on the same runway buff- ers or cushioning devices should be provided from the crane and a stationary platform built at the edge of the runway to be used by workmen when making repairs or else a landing stage built alongside the crane when repair work is done at both ends of the bridges c Fenders trucks andand trolley trucks should be equipped with fenders which extend below the top of the rail and project in front of the truck wheels 4. Stairways overhead traveling crane operated from a cage should be provided with a stairway or fixed ladder between the cage and the crane footwalk and between the cage and the floor d Brakes independent hoisting unit of a crane should be equipped with two braking Stairways should be equipped with rigid and substantial metal handrails as described in Part means except geared hoists the angle of whose worm is such as to prevent the load from accelerating in the lowering direction One brake should be applied directly to the motor shaft or some part of the reducing gear and may be either electrically operated or me- chanical The other brake may be either me- chanical or electrical If mechanical it should lock the load when hoisting is stopped and should also control the speed during lowering II B and should be at an angle of not more than 50 with the horizontal A suitable emergency exit should be provided where hazards justify such precautions A warning signal such as a gong siren or bell should be provided on all traveling cranes 5. Crane Enclosures Indoor cranes cage floor of every indoor over- head traveling crane should be solid except that grating with openings not exceeding inch in 21 _ _ to the cornea and to the deeper structures of the eye The eye must be regarded as the most exposed most easily injured most sensitive and most valuable of the special sense organs It must be considered that the most minor eye injury can most quickly develop the most dangerous complications Removal of foreign bodies under the lids should be done with ex- treme care and removal of particles driven into the cornea transparent front of the eye should be done only by the plant physician if skilled in this work or by the eye specialist B. ENVIRONMENTAL CONDITIONS AND PERSONAL SERVICES 1. Control of atmospheric contaminants.a Workers shall not be exposed to concentrations of atmospheric contaminants hazardous to health maximum The most recent values for maximum con- centrations as recommended by the American Conference of Governmental Industrial Hy- gienists shall be used as a guide in appraising occupational health hazards and in evaluating controls Maximum concentrations shall not be used as the sole criterion for establishing evidence of hazard to health or being but the evaluation of a possible hazard shall also be subject to other pertinent factors such as the nature of the contaminant and the frequency and dura- tion of exposure or clinical evidence of harmful effects b Control of atmospheric contaminants may be accomplished by any of the following methods i Substitution of a less toxic material for the material contaminating the workroom atmosphere ii Exhaust ventilation so that the con- taminant is removed from the workroom atmosphere iii Isolation of the operation so that the contaminant does not enter the general workroom atmosphere in hazardous concentrations provided that any worker who is exposed to a health hazard by entering the isolated area shall be furnished personal protection in accordance with the provisions of this code See sec 6 hereafter iv Enclosure of the operation so that the contaminant does not escape into the workroom atmosphere in hazardous concentrations v Change the process or operating method such as by wet methods the use of foams colloids etc. so that the hazard is controlled vi Increase of general ventilation so that the contaminant is diluted to a safe concen- tration c The most recent values for maximum concentrations as recommended by the American Conference of Governmental Industrial Hygienists should be used as a guide in appraising occupational health hazards and in evaluating control Maximum concentrations should not be used as the sole criterion for establish- ing evidence of hazard to health or being but the evaluation of a possible hazard should also be subject to other pertinent factors such as the nature of the contaminant and the fre- quency and duration of the exposure or clinical evidence of harmful effects The following are examples MAXIMUM ALLOWABLE CONCENTRATIONS Threshold limit values adopted April 1950 at Chicago Ill Hygienists American Conference of Governmental Industrial GASES AND VAPORS Parts per million 1 percent 10,000 p m Substance P. m Acetaldehyde 200 Acetic acid 10 Acetic anhydride Aceton ... 5 500 Acrolein 0.5 Acrylonitrile 20 Ammonia 100 Amylacetate Amyl alcohol Aniline one * ee Arsine benzol benzol eee eee Benzene benzol * Bromine 200 100 5 0.05 35 1 Butadiene Butanol 1,000 100 Butanone 250 Butyl acetate Butyl cellosolve Carbon dioxide Carbon disulfide . 200 200 5,000 20 Carbon monoxide 100 Carbon tetrachloride 50 Substance P. Cellosolve Cellosolve acetate__ Chlorine Chlorobutadiene Chloroform 200 100 1 25 100 nitropropane Cyclohexane _--- Cyclohexanol Cyclohexanone Cyclohexene Cyclopropane propene Dichlorobenzene Dichloro ethane Dichloropropane propyl- ene dichloride ...__...-...-.. Dichlorotetrafluoroethane Freon ---..--------.---- Dimethylaniline Dimethylsulfate Dioxane 20 400 100 100 400 400 50 10 75 1,000 5 1 100 Ethyl acetate Ethyl alcohol 400 1,000 Recommended Recommended lower concentration but not specific value Substance P. Ethyl benzene Ethyl bromide Ethyl chloride Ethylene chlorohydrin Ethylene dichloride _.__ Dichloroethane Ethyl- ene oxide 200 200 1,000 - 5 75 100 Ethyl ether Ethyl formate Ethyl silicate Formaldehyde one Gasoline Heptane Hexa chloride en ee e ee Hydrogen chloride Hydrogen cyanide Hydrogen fluoride Hydrogen selenide Hydrogen sulfide Iodine __. 400 100 100 5 500 500 500 5 10 3 0.05 20 1 Isophorone . 25 Mesityl oxide 50 GAS AND Continued Substance P. m Substance P. m Methanol 2 ee Methyl acetate Methyl propanone pentanone . own ween Monochlorobenzene Monofluorotrichloro Freon .__---0..-.--- Mononitrotoluene- Naphtha coal tar Naphtha ( petrol. eum NicNikckeellNickel carbonyl carcarb bonyl onyl Nitrobenzene Nitroethane Nitrogen oxides other than N O Nitroglycerin o Nitroglycerin Nitromethane Nitropropane Octane . Ozone Pentanee ee 200 200 200 75 1,000 1,000 200 500 1 1 100 25 0.5 100 50 500 1 1,000 Pentanone Methyl none _ 2-- anne ee propa- nen ee ee Phosgene Phosphine Phosphorus Trichloride Propanol Propene cyclopropane . Propyl acetate Propylene dichloride dichloropropane iso- Propyl ether Stibine Stoddard solvent Styrene monomer Sulfur chloride Dichlorodifluoromethane Freon Dichloroethane Dichloroethane ethylene dichloride ._.....-....-.-.---- Dichloroethylene Dichloroethyl ether .. 200 1 0.05 0.5 400 400 200 75 500 0.1 500 200 1 1,000 100 200 15 Recommended lower concentration but not specific value Substance P. Dichloromethane 500 Dichloromonofluoromethane Freon 2.0. 22..0--------- Methyl bromide Methyl butanone Methyl cellosolve Methyl cellosolve acetate__ acetate__ Methyl chloride Methylcyclohexane - Methylcyclohexanol Methycyclohexanone Methyl formate Methyl isobutyketone . Sulfur dioxide Tetrachloroethane Tetrachloroethylene Toluene Toluidine 20 25 25 100 500 100 100 100 100 10 5 100 200 5 Trichloroethylene Turpentine .. eee Vinyl chloride Xylene 100 100 500 200 TOXIC DUSTS FUMES AND MISTS Milligrams per cubic meter of air Substance Mo./cu.m Mo./cu.m Antimony eee eee nee eee eee eee 0.5 Arsenic en eee eee eee eee eee nee eee 0.5 Barium. een nnn ee eee ee eee 0.5 Cadmium 0.1 Chlorodiphenyl 1 Chromic acid and chromates as C O 0.3 1 Cyanide as CN Dinitroc ---r --- --e ---ens neeeeeo ne el o Dinitroto2l -2 =u en ne eencen eeee ene Fluoride 22-2 ---- ween nnn cece ener en nee Iron oxide fume 5+ ... Lead __--- 22-7 == ene enn nnn e nee cere ee eee 5 0.2 1.5 2.5 15 0.15 Magnesium oxide fume 15 Recommended lower concentration but not specific value Substance Mg./cu.m Mg./cu.m Mg./cu.m Manganese 98822 Mercury Pentachloronaphthalene 02.2.2 _. - eee 98822 98822 Pentachlorop eeeh eeee e annn e no el n 98822 Phosphorus yellow 98822 sooceee pentachloride Phosphorus GrHO T pentasulfide nena Selenium.. . 0.1 Sulfuric acid GrGHOHOT Tellurium 0.1 Tetryl Trichloronaphthalene ee_e Trinitrotoluen eee e seen Zinc oxide fume 1.5 GrGHOHOT 1.5 GrGHOHOT MINERAL DUSTS Million particles per cubic foot of air Substance M. p Alundum eee neee nee eee eee eee Asbees ee eeet eeeeeo eeee ees nee ener ee eee*. Carborundum Dust nuisance no free silica * ------- Mica below 5 percent free silica Portland cement 2-02-2222 een en nnn en ee eee eee Talc oe neee ee eee eee eee ee eee ee eee eee p f 50 848 8 8 8488888 8488888 8488888 8488888 20 Recommended lower concentration but not specific value Substance M. p f Silic*a High above 50 percent free SiO2 . Anggra Medium 5 to 50 percent free SiO2 . Anggra Low below 5 percent free SiO 0.2.2. Anggra Slate below 5 percent free SiO __..-.-- ue Anggra Soapstone below 5 percent free SiO Anggra Total dust below 5 percent free SiO2 . Anggra RADIATIONS Material or radiation Radiant energy Gamma milliroentgen per week . ray milliroentgen per week ------....-..----Radon curies per cubic meter . Thoron curies per cubic meter 300 300 10-8 10-8 10-8 curics 370 disintegrations per second -0.01 microgram radium New substances being studied Asphalt fumes and dust Beryllium 0.005 cu.m DDD DDT Ketene eee Monochloromonobromomethane Values not established Diethylene glycol Dipropylene glycol Ethylene glycol Propylene glycol Tricthylene glycol 2. Infectious Measures shall be provided to eliminate or control the transmission of infectious diseases through processing or handling industrial products or wastes 3. General ventilation and temperature requirements Outside air shall be provided to all workrooms at the rate of 15 cubic feet per minute per person or one and half air changes per hour whichever is greater In most instances leakage through walls doors and windows will produce at least one and onehalf air changes per hour b Air circulated in any workroom shall be supplied through air inlets arranged located 24 = and equipped so that workers are not subjected h Suitable air inlets shall be provided for to air velocities exceeding 200 feet per minute replacement of air exhausted except under special circumstances i Exhaust systems handling dusts and dis- c In appraising and controlling health haz- charging to the outer air shall be provided with ards associated with extremes of temperature suitable cleaning devices to remove air con- and humidity the most recent report of the taminants prior to the discharge to the outer Committee on Atmospheric Comfort of the In- dustrial Hygiene Section of the American Public air except under unusual circumstances 1 The discharge from any exhaust system Health Association is suggested as a guide shall be such that no air contamination there- d A minimum air temperature of 60 F. should be maintained at all workrooms where from will enter any window door or other opening of any work space in quantities suf- work of a strenuous nature is performed and ficient to create a health hazard to such space a minimum air temperature of 65 F. should be or create a nuisance to surrounding areas maintained in all other workrooms unless pro- k Collected materials shall be removed at hibited by process requirements intervals frequent enough to insure that the ex- e Air from any exhaust system handling materials listed under section 1 paragraph c shall not be recirculated unless the equipment is haust system will meet the requirements of section 5 paragraph b at all times 1 Collected materials shall be disposed of checked frequently to be certain that its opera- tion is efficient at all times in a manner which will not result in a nuisance or health hazard e e 4. Local exhaust ventilation The air 5. Personal protective equipment Per- velocity and rate of air flow as hereinafter sonal protective equipment shall not be used in required through a hood booth enclosure or lieu of control measures specified in section 1 other point of ventilation and through the paragraph b except under unusual circum- pipes shall be maintained at all times when the stances where the use of such control measures machine or process for which the ventilation is is impracticable applied is in operation or use b Personal protective equipment and b The effectiveness of every local exhaust protective barriers shall be provided whenever ventilation system shall be judged by substances radiations or mechanical irritants i The ability of the hoods booths or other are encountered in a manner capable of causing injury or impairment in function of any part openings to produce a movement of air toward of the body through skin and mucous mem- the opening sufficient to prevent escape of con- brane absorption taminant to the workroom beyond the limits c Personal protective equipment shall be shown in section 1 paragraph c fitted to each exposed worker when the wearing > ii Air flow through branch and main ducts of such equipment is necessary for worker pro- shall be sufficient to transport the contaminant tection and shall be maintained in an efficient 2 through the system without settling and sanitary condition c Piping shall be located so as to be acces- d Workers who handle or are exposed to sible for inspection and maintenance harmful materials in such a manner that con- d Air flow equipment including hoods tact of work clothes with street clothes will pipes fans motors and collectors shall be effec- communicate to the latter the harmful sub- tively grounded stances accumulated during working hours e Two or more operations involving more should be provided with facilities which will than one substance shall not be permitted to be prevent this contact and also permit the free connected to the same exhaust system when a ventilation or drying of the work clothes while combination of the substances removed may they are not in use In any plant where it is et Melt constitute a fire hazard an explosion hazard or necessary for both male and female employees otherwise dangerous mixture to change clothes separate dressing rooms Se f Those processes or operations using or should be provided SIE generating flammable dusts gases fumes 6. Eye protection protection should be I OE IMATE vapors mists fibers or other impurities shall provided where persons are exposed to any be completely protected from all sources of hazard which may reasonably be expected to MOE ignition cause injury to the eyes AO. g The capacity of an exhaust system shall Such hazards are be calculated on the basis of all hoods booths a Relatively large flying particles There and enclosures connected to the system being are many operations and processes where this open except where the system is so interlocked hazard occurs Some of these are chipping that only a portion of it can be operated at a calking coarse grinding some riveting opera- given time in which case the capacity should be tions and sledging in quarries calculated on the basis that all the hoods in the b Dust and small flying particles There group requiring the greatest volume rate of are many operations and processes where this exhaust are open hazard occurs Some of these are scaling light 25 grinding stone dressing spot welding and some woodworking and working operations c Splashing There are many op- erations and processes where this hazard occurs Some of these are babbitting casting of hot metal and dipping in hot metal baths liquids.- d Injurious gases fumes and liquids.- There are many operations and processes where this hazard occurs Some of these are encoun- tered in the handling of acids and caustics e Injurious radiant energy are many operations and processes where this haz- ard occurs Some of these are electric arc welding oxyacetylene and oxyhydrogen welding and cutting furnace tending and irradiation with ultraviolet light should be provided for the disposal of used cups Containers for drinking water from which the water must be dipped or poured should not be allowed 2. Toilet facilities Every place of employ- ment should be provided with adequate closets chemical closets or privies separate for each sex in accordance with the following table in which the number of persons is the maximum number of each sex employed at any one time on the premises for which facilities are fur- nished Number of persons 1 to 9 _ Minimum Minimum wee number of -23454 7. Noise Noise should be reduced or eliminated as a means of preventing fatigue or accidents b Some appropriate means of noise reduc- 1 For each additional 30 persons tion are Urinals instead of water closets for male em- i Sound absorbing partitions ployees may be substituted in a ratio of not more ii Segregation of the noisy process than third urinals in the above minimum iii Provision of appropriate ear stopples to facility schedule employees affected 8. Lunchrooms rooms in which employees may eat their lunches should be provided in plants where employees are exposed to Where chemical closets are used they shall be of a type approved by the local health authority and maintained in a clean and sanitary condition at all times Janitor service should harmful materials in the workrooms Such be scheduled and frequent rooms should be maintained in a clean and sani- tary condition at all times and they should be ventilated illuminated and heated properly and Privies should not be permitted where more than 25 people are employed and no privy should be permitted within 100 feet of any room adequately in which foodstuffs are stored or handled No. 9. Housekeeping All places of employ- privy should be used unless it can be located ment passageways storerooms service rooms constructed and maintained without danger of machinery equipment and supplies shall be kept contaminating any sources of drinking water vny in a clean and sanitary condition with all un- Construction installation and ventilation of Pern necessary dust spillage and debris removed at toilet rooms and facilities shall conform to the regular intervals frequent enough to maintain requirements of the local public health authority Sores good housekeeping b Where wet processes are used reasonable drainage shall be maintained and false having jurisdiction Waste receptacles with covers should be kept in all toilet rooms They should be emptied at floors platforms mats or other dry standing places shall be provided c So far as possible sweeping and cleaning shall be done in such a manner as to avoid the contamination of the air with dust during working hours regular frequent intervals An adequate supply of toilet paper in proper holders should be provided in each toilet room All toilets should have solid partitions separating them from workrooms They should be effectively separated and designated as to sex C. SPECIAL SANITATION SERVICES 1. Drinking There should be provided in all places of employment a supply of potable clean cool safe drinking water ap- and should be lighted and ventilated adequately Windows may be translucent but not trans- parent 3. Washrooms place of employment shall be provided with adequate washing facili proved as to source and supply by the local ties in the ratio of 1 lavatory or equivalent authority having jurisdiction The common wash place for each 10 employees up to 100 drinking cup is prohibited persons and 1 lavatory wash place for each Drinking facilities readily accessible to all employees and of a type approved by the local additional 15 persons Each lavatory wash place shall be provided with soap and hot and authority having jurisdiction shall be provided in the ratio of 1 facility for each 100 employees cold running water Individual clean towels of cloth or paper shall be provided Other apparatus for drying the When individual drinking cups to be used only once are supplied a suitable container hands shall be substituted only after approval by the local health authority having jurisdiction 26