2. University of Arkansas at Little Rock
Radiation Safety Program: Regulations and Practical Considerations for Safe Use of Radioactivity
Radiation Safety Office
ETAS-239
Graduate Institute of Technology, UALR
University of Arkansas at Little Rock

3. Ionizing and Non-ionizing radiation?
Radiation carries a range of energy forming an electromagnetic spectrum.
Radiation that does not have enough energy to break chemical bonds but can vibrate atom is referred to as “Non-ionizing Radiations” e.g. radiowaves, microwaves, infrared, visible light etc.
Radiation that has enough energy to break chemical bonds is referred to as 'ionizing radiation, e.g. alpha particles, beta particles, gamma rays etc.

4. Ionizing Radiation

5. How to know if there is a radiation source or radiation area- Symbols?

6. "CAUTION RADIATION AREA"
How to know if there is a radiation source or radiation area- Symbols?
"CAUTION RADIATION AREA"
“CAUTION RADIOACTIVE MATERIALS"

7. Radiation Package Symbols

15. Radiation Protection Procedures
External Radiation Protection
Internal Radiation Protection
Survey Procedures or Monitoring
Radiation Spills
Waste Disposal Guidelines

16. A-L-A-R-A Radiation Dose Limit
ALARA is an acronym meaning As Low As Reasonably Achievable. It is a requirement of the agreement state (ADH) that all facilities possessing radioactive materials licenses to have a formal ALARA program. It is the policy of University of Arkansas at Little Rock to keep this exposure as low as reasonably achievable (ALARA).  

17. General Handling Precautions
Protective Clothing:
lab coats, gloves, masks, eye protection, sealing tapes etc
The Work Place
Designate Clean area, Hood, Absorbent paper, drip trays, locks, no food items
Manipulations of Radioactive Materials
plan ahead, pippetting, use minimum amounts, sealing tubes, reduce volatilization, proper monitoring, shielding, dosimeter, public perception

18. External Radiation Protection:
The Three Basic Rules
Time: Dose = Dose Rate x Time
Distance: The Inverse Square Law
ER2 = ER2 x (D1/D2)^2
Shielding: Radiation Energy
Shield Density
Shield Thickness
Bremsstrahlung
HVL & TVL
Concerns

19. Internal Radiation Protection
Mode of Entry into Body
Inhalation
Ingestion
Absorption
Injection

20. Individuals Requiring Radiation Safety Training
Three general categories of UALR employees with respect to their exposure to radiation:
Radiation Workers: Those workers whose major responsibilities involve working with sources of ionizing radiation or radioactive material.
Ancillary Workers: All personnel who may come in contact with or enter an area that contains radioactive material or sources of ionizing radiation e.g. janitorial staff.
Non-Radiation Workers: personnel who would not normally be expected to encounter radioactive material or radiation sources in the course of their employment at UALR. This group does not require radiation training.

21. Emergency Contacts Radiation Safety Officer 501-569-8210
Assistant Radiation Safety Officer
After Hours: Public Safety
Also check “NRC Notice to Employees” posted in the radiation use and storage areas

22. Part 1: Fundamentals of Laser Operation

23. Continuous Output (CW)
Laser Output
Continuous Output (CW)
Pulsed Output (P)
                       
Energy (Watts)
Time
Energy (Joules)
Time
watt (W) - Unit of power or radiant flux (1 watt = 1 joule per second).
Joule (J) - A unit of energy
Energy (Q) The capacity for doing work. Energy content is commonly used to characterize the output from pulsed lasers and is generally expressed in Joules (J).
Irradiance (E) - Power per unit area, expressed in watts per square centimeter.

24. Types of Laser Hazards
Eye : Acute exposure of the eye to lasers of certain wavelengths and power can cause corneal or retinal burns (or both). Chronic exposure to excessive levels may cause corneal or lenticular opacities (cataracts) or retinal injury.
Skin : Acute exposure to high levels of optical radiation may cause skin burns; while carcinogenesis may occur for ultraviolet wavelengths ( nm).
Chemical : Some lasers require hazardous or toxic substances to operate (i.e., chemical dye, Excimer lasers).
Electrical : Most lasers utilize high voltages that can be lethal.
Fire : The solvents used in dye lasers are flammable. High voltage pulse or flash lamps may cause ignition. Flammable materials may be ignited by direct beams or specular reflections from high power continuous wave (CW) infrared lasers.

25. Lasers and Eyes What are the effects of laser energy on the eye?
Laser light in the visible to near infrared spectrum (i.e., nm) can cause damage to the retina resulting in scotoma (blind spot in the fovea). This wave band is also know as the "retinal hazard region".
Laser light in the ultraviolet ( nm) or far infrared ( ,600 nm) spectrum can cause damage to the cornea and/or to the lens.
Photoacoustic retinal damage may be associated with an audible "pop" at the time of exposure. Visual disorientation due to retinal damage may not be apparent to the operator until considerable thermal damage has occurred.

26. MULTIPLE PULSE RETINAL INJURY
This is an image of the retina of a human who experienced an eye injury from a repetitive pulse near infrared laser. The beam was invisible. In such cases people do not usually realize they are being exposed until their vision has been severely effected. The person’s eye was moving during this exposure. This resulted in a line of laser burns on the retina. This is a color enhanced image to better show the laser damage.
The macula of the eye is located out of the photo to the lower left. This individual was lucky that the damage did not extend into the macula.
The laser safety eyewear would have prevented this injury.
Laser-Professionals.com

27. EYE INJURY BY Q-SWITCHED LASER
Retinal Injury produced by four pulses from a Nd:YAG laser range finder.
This is a human eye injury resulting from four pulses into the macular region from an AN/GVS-5 Nd:YAG laser rangefinder. The pulse duration was about 20 ns and the pulse energy was about 15 mJ. The safe exposure limit for this pulse duration is 2 mJ per pulse. Thus, this exposure was 7500 times the safe level.
Short pulse lasers produce the greatest eye hazards. Each short pulse results in a tiny explosion in the retina. The resulting shockwave causes severe damage to the retinal tissue.
This photo was taken three weeks after the exposure. It shows the permanent destruction of the macular region. Visual acuity in the eye is approximately 20/400 and will not improve.
This injury could not have occurred if the individual had been wearing the appropriate laser safety eyewear.
Photo courtesy of U S Army Center for Health Promotion and Preventive Medicine
Laser-Professionals.com

28. Skin Hazards
Exposure of the skin to high power laser beams (1 or more watts) can cause burns. At the under five watt level, the heat from the laser beam will cause a flinch reaction before any serious damage occurs. The sensation is similar to touching any hot object, you tend to pull your hand away or drop it before any major damage occurs.
With higher power lasers, a burn can occur even though the flinch reaction may rapidly pull the affected skin out of the beam. These burns can be quite painful as the affected skin can be cooked, and forms a hard lesion that takes considerable time to heal.
Ultraviolet laser wavelengths may also lead to skin carcinogenesis.

29. SKIN BURN FROM CO2 LASER EXPOSURE
Most laser skin injuries are thermal in nature. Exposure to high power beams at all wavelengths can result in skin burns. These burns usually do not lead to long-term disability, but they can have painful short-term consequences. Far IR light, such as that from CO2 lasers, is absorbed strongly by water in the skin and results in a surface burn. Near IR light with wavelengths close to 1 mm, such as that from a Nd:YAG laser, penetrates more deeply into tissue and can result in deeper, more painful burns.
If a high power laser beam is focused on the skin, it can vaporize tissue and drill a hole or produce a cut if the beam or tissue is moving. CW beams will cauterize the tissue preventing bleeding. Focused short pulses form repetitive pulse Q-switched lasers vaporize tissue without heating the surrounding tissue enough to cauterize. Exposures to focused Q-switched beams can result in cuts several millimeters deep that bleed freely.
Photochemical skin injuries include sunburn and the possibility of promoting skin cancer by repeated low level exposures over long periods of time. The best way to avoid this issue is to enclose high power UV beams.
Accidental exposure to partial reflection of 2000 W CO2 laser beam
from metal surface during cutting
Laser-Professionals.com

30. Other Hazards Associated with Lasers
Chemical Hazards
Some materials used in lasers (i.e., excimer, dye and chemical lasers) may be hazardous and/or contain toxic substances. In addition, laser induced reactions can release hazardous particulate and gaseous products.
(Fluorine gas tanks)
Electrical Hazards
Lethal electrical hazards may be
present in all lasers, particularly
in high-power laser systems.
Secondary Hazards including:
cryogenic coolant hazards
excessive noise from very high energy lasers
X radiation from faulty high-voltage (>15kV) power supplies
explosions from faulty optical pumps and lamps
fire hazards

31. Laser Class The following criteria are used to classify lasers:
Wavelength. If the laser is designed to emit multiple wavelengths the classification is based on the most hazardous wavelength.
For continuous wave (CW) or repetitively pulsed lasers the average power output (Watts) and limiting exposure time inherent in the design are considered.
For pulsed lasers the total energy per pulse (Joule), pulse duration, pulse repetition frequency and emergent beam radiant exposure are considered.

32. CLASS 1 Safe during normal use Incapable of causing injury
Low power or enclosed beam
CLASS 1
CLASS I Laser Product
A class 1 laser is incapable of causing an injury during normal use. Lasers can be class 1 because they are very low power or because the beam is fully enclosed. The operators of class 1 lasers do not need to take any precautions to protect themselves from laser hazards.
The class 1 limits for visible lasers under the 2000 version of the ANSI Standard vary with laser wavelength. Visible lasers with wavelengths longer than 500 nm have a class 1 limit of 0.4 mW. The class 1 limit for visible lasers with wavelengths shorter than 450 nm is 40 mW. Power limits have been increased from the 1993 version because we now know that they had been set lower than necessary for safety.
The class 1 limits of the IEC International Standard are similar to those of the ANSI Standard.
The CDRH class 1 limit is 0.4 microwatts for the entire visible. The power limits of federal law have not yet been changed since it took effect in 1976.
Label not required
May be higher class during
maintenance or service
Nd:YAG Laser Marker
Laser-Professionals.com

33. CLASS 2 Staring into beam is eye hazard
Eye protected by aversion response
Visible lasers only
CW maximum power 1 mW
CLASS II LASER PRODUCT
Laser Radiation
Do Not Stare Into Beam
Helium Neon Laser
1 milliwatt max/cw
Laser Scanners
Class 2 lasers must be visible. The natural aversion response to bright light will cause a person to blink before a class 2 laser can produce an eye injury.
The average for a human aversion response to bright light is 190 ms. The maximum aversion time is always less that 0.25 s.
The only protection you need from a class 2 laser is to know not to overcome the aversion response and stare directly into the beam. This has been done, and people have burned their retinas doing it.
Laser-Professionals.com

34. CLASS 3a Aversion response may not provide adequate eye protection
CDRH includes visible lasers only
ANSI includes invisible lasers
CW maximum power (visible) 5 mW
Expanded Beam
CLASS IIIa LASER PRODUCT
Laser Radiation-
Do Not Stare Into Beam or View
Directly With Optical Instruments
Helium Neon Laser
5 milliwatt max/cw
Laser Pointers
Class 3a lasers are “Marginally Unsafe.” This means that the aversion response is not adequate protection for a direct exposure of the eye to the laser beam, but the actual hazard level is low, and minimum precautions will result in safe use.
The CDRH Standard (FLPPS) allows only visible lasers in class 3a. The CW power is limited to 5 mW. If the laser has a small beam so that more than 1 mW can enter the pupil of the eye, it carries a DANGER label. If the beam is expanded to be large enough that only 1 mW can pass through the pupil, the laser carries a CAUTION label.
The ANSI Standard has the same limits for visible class 3a lasers. It also allows invisible lasers in this class. An invisible laser with 1 to 5 times the class 1 limit is a class 3a invisible laser under the ANSI Standard.
The only precautions required for safe use of a class 3a laser are that the laser user must recognize the level of hazard and avoid direct eye exposure.
LASER RADIATION-
AVOID DIRECT EYE EXPOSURE
Small Beam
ND:YAG 532nm
5 milliwatts max/CW
Laser-Professionals.com
CLASS IIIa Laser Product

35. AVOID DIRECT EXPOSURE TO BEAM
CLASS 3b
Direct exposure to beam is eye hazard
Visible or invisible
CW maximum power 500 mW
DPSS Laser with cover removed
CLASS IIIb Laser Product
LASER RADIATION-
AVOID DIRECT EXPOSURE TO BEAM
2w ND:YAG Wavelength: 532 nm
Output Power 80 mW
Class 3b lasers are hazardous for direct eye exposure to the laser beam, but diffuse reflections are not usually hazardous (unless the laser is near the class limit and the diffuse reflection is viewed from a close distance).
The maximum average power for a CW or repetitive pulse class 3b laser is 0.5 W.
The maximum pulse energy for a single pulse class 3b laser in the visible and near IR varies with the wavelength. For visible lasers the maximum pulse energy is 30 mJ. It increases to 150 mJ per pulse in the wavelength range of nm. For the ultraviolet and the far IR the limit is 125 mJ.
Class 3b lasers operating near the upper power or energy limit of the class may produce minor skin hazards. However, this is not usually a real concern.
Most class 3b lasers do not produce diffuse reflection hazards. However, single pulse visible or near IR class 3b lasers with ultrashort pulses can produce diffuse reflection hazards of more than a meter. Your laser safety officer will perform a hazard analysis.
Courtesy of Sam’s Laser FAQ, ©
Laser-Professionals.com

36. CLASS 4 Exposure to direct beam and scattered
light is eye and skin hazard
Visible or invisible
CW power >0.5 W
Fire hazard
CLASS IV Laser Product
VISIBLE LASER RADIATION-
AVOID EYE OR SKIN EXPOSURE TO DIRECT OR SCATTERED RADIATION
2w Nd:YAG
Wavelength: 532 nm
Output Power 20 W
Class 4 lasers are powerful enough that even the diffuse reflection is a hazard. The lower power limit for CW and repetitive pulsed class 4 lasers is an average power of 0.5 W. The lower limit for single pulse class 4 lasers varies from 0.03 J for visible wavelengths to 0.15 J for some near infrared wavelengths.
Class 4 lasers require the application of the most stringent control measures.
Photo: Keith Hunt -
Copyright: University of Sussex, Brighton (UK)
Laser-Professionals.com

37. ANSI Classifications
Class 1 denotes laser or laser systems that do not, under normal operating conditions, pose a hazard.
Class 2 denotes low-power visible lasers or laser system which, because of the normal human aversion response (i.e., blinking, eye movement, etc.), do not normally present a hazard, but may present some potential for hazard if viewed directly for extended periods of time (like many conventional light sources).

38. ANSI Classifications (cont’d)
Class 3a denotes some lasers or laser systems having a CAUTION label that normally would not injure the eye if viewed for only momentary periods (within the aversion response period) with the unaided eye, but may present a greater hazard if viewed using collecting optics. Class 3a lasers have DANGER labels and are capable of exceeding permissible exposure levels. If operated with care Class 3a lasers pose a low risk of injury.
Class 3b denotes lasers or laser systems that can produce a hazard it viewed directly. This includes intrabeam viewing of specular reflections. Normally, Class 3b lasers will not produce a hazardous diffuse reflection.
Class 4 denotes lasers and laser systems that produce a hazard not only from direct or specular reflections, but may also produce significant skin hazards as well as fire hazards.

39. Reflection Hazards (cont’d)
Specular Reflection
Diffuse Reflection

40. CONTROL MEASURES Engineering Controls Interlocks Enclosed beam
Administrative Controls
Standard Operating Procedures (SOPs)
Training
Personnel Protective Equipment (PPE)
Eye protection

41. Common Laser Signs and Labels

42. LASER SAFETY EYEWEAR
Laser safety eyewear is available in glass or plastic for all laser wavelengths. The required Optical Density of the eyewear is determined in the hazard analysis performed by the LSO.
Eyewear should never be viewed as the first control measure to be applied. In all cases engineering and procedural controls should be devised to reduce and limit the possible exposure to hazardous laser light. The use of eyewear should then be required as a last line of defense in case everything else fails. Most laser eye injuries have occurred when other controls proved inadequate and the worker was not wearing eyewear.
Eyewear would have prevented most laser eye injuries, but it does not make the wearer invulnerable. It is never safe to stare into a laser beam, even if wearing laser protective eyewear.
The greatest risk of eye injury occurs when near IR lasers are operated with the beam exposed.
Eyewear should always be worn when a near IR class 3b or class 4 beam is accessible.
Laser-Professionals.com

43. LASER PROTECTIVE BARRIER
Laser protective barriers are often used to enclose laser hazards when an industrial laser system must be operated with the beam exposed during maintenance or service.
Laser protective barriers and curtains can also be used to limit the NHZ inside laser controlled areas. These barriers are often used to protect entryways, computer work stations, and workbenches where workers are likely to remove laser protective eyewear. It is especially important that no direct optical path exist between laser optics tables and computer stations in laser laboratories.
Photo courtesy of
Laser-Professionals.com

44. WHO HAS PRIMARY RESPONSIBLITY FOR LASER SAFETY ANY TIME A CLASS 4 LASER IS OPERATED?
The person operating the laser always has the primary responsibility for all hazards associated with laser use.
Laser user responsibility is one of the key concepts in the ANSI Standard. In all cases the primary responsibility for laser safety rests with the person operating the laser. If you create a laser hazard, you own that hazard, and you must make sure that no one is endangered by your hazard. If laser users always take responsibility for managing the hazards they create, there will be no chance of injury to themselves or other personnel.
In most cases the operators of class 4 laser systems will perform all activities in accordance with a written Standard Operating Procedure (SOP). If unusual conditions not covered by the SOP are encountered, the laser user must be prepared to make good decisions to assure safe conditions.
All operators of class 3b and 4 lasers must have comprehensive laser safety training to make sure that they are capable of taking responsibility for laser hazards.
The first responsibility of laser users is to protect others. Important steps in accomplishing this are blocking all hazardous beams and stray reflections, making sure others present are aware of the potential laser hazards and are wearing the appropriate laser protective eyewear, and constantly assessing the hazards in their workplace.
The second responsibility of laser users is to protect themselves. Important steps in accomplishing this are wearing laser protective eyewear when required for safety, avoiding unnecessary risks, and constantly assessing the hazards in their workplace.
Laser-Professionals.com

45. SAFE BEAM ALIGNMENT Most beam injuries occur during alignment.
Only trained personnel may align class 3B or class 4 lasers (NO EXCEPTIONS!)
Laser safety eyewear is required for class 3B and class 4 beam alignment.
ANSI REQUIRES approved, written alignment procedures for ALL class 4 laser alignment activities and recommends them for class 3B.
Safety during beam alignment is of critical importance.
Most eye injuries occur when untrained personnel attempt beam alignment without approved, written procedures and laser safety eyewear. Most of those injured are students.
Only personnel who have completed laser safety training should ever perform laser alignment. Alignment of many research systems requires specific training on the system by experienced personnel.
Written alignment procedures are required for class 4 laser alignment and are recommended for class 3b alignment. Alignment procedures should be written by experienced laser personnel and approved by the LSO. These procedures should identify beam hazards during alignment and specify the control measures and eyewear to be used during alignment.
Laser-Professionals.com

46. INTRODUCTION Flammable or combustible Explosive Corrosive Poisonous
Compressed gases present a unique hazard. Depending on the particular gas, there is a potential for simultaneous exposure to both mechanical and chemical hazards. Gases may be:
Flammable or combustible
Explosive
Corrosive
Poisonous
Inert
or a combination of hazards
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47. INTRODUCTION
Careful procedures are necessary for handling the various compressed gases, the cylinders containing the compressed gases, regulators or valves used to control gas flow, and the piping used to confine gases during flow.
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48. IDENTIFICATION
The contents of any compressed gas cylinder must be clearly identified. Such identification should be stenciled or stamped on the cylinder or a label. Commercially available three-part tag systems may also be used for identification and inventory.
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49. HANDLING & USE
Cylinders may be attached to a bench top, individually to the wall, placed in a holding cage, or have a non-tip base attached. Chains or sturdy straps may be used to secure them.
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50. HANDLING & USE
Standard cylinder-valve outlet connections have been devised by the Compressed Gas Association (CGA) to prevent mixing of incompatible gases.
The outlet threads used vary in diameter; some are internal, some are external; some are right-handed, some are left-handed.
In general, right-handed threads are used for non-fuel and water-pumped gases, while left-handed threads are used for fuel and oil-pump gases.
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51. HANDLING & USE
Cylinders should be placed with the valve accessible at all times. The main cylinder valve should be closed as soon as it is no longer necessary that it be open (i.e., it should never be left open when the equipment is unattended or not operating).
This is necessary not only for safety when the cylinder is under pressure, but also to prevent the corrosion and contamination resulting from diffusion of air and moisture into the cylinder after it has been emptied.
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52. HANDLING & USE
Cylinders are equipped with either a hand wheel or stem valve. For cylinders equipped with a stem valve, the valve spindle key should remain on the stem while the cylinder is in service.
Only wrenches or tools provided by the cylinder supplier should be used to open or close a valve. At no time should pliers be used to open a cylinder valve.
Some valves may require washers; this should be checked before the regulator is fitted.
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53. HANDLING & USE
Cylinder valves should be opened slowly. Oxygen cylinder valves should be opened all the way.
Open up the oxygen cylinder valve stem just a crack.  Once the needle on the high pressure gauge has stopped, open up the valve all the way.  This back-seats the valve.
Oxygen cylinders must have the valve opened up all the way because of the high pressure in the cylinder.  There is a back-seating valve on the oxygen cylinder.   This prevents the high-pressure gas from leaking out through the threaded stem.
When opening the valve on a cylinder containing an irritating or toxic gas, the user should position the cylinder with the valve pointing away from them and warn those working nearby.
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54. HANDLING & USE
Cylinders containing flammable gases such as hydrogen or acetylene must not be stored in close proximity to open flames, areas where electrical sparks are generated, or where other sources of ignition may be present.
Cylinders containing acetylene shall never be stored on their side.
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55. HANDLING & USE
Oxygen cylinders, full or empty, shall not be stored in the same vicinity as flammable gases.
The proper storage for oxygen cylinders requires that a minimum of 20 feet be maintained between flammable gas cylinders and oxygen cylinders or the storage areas be separated, at a minimum, by a fire wall five feet high with a fire rating of 0.5 hours.
Greasy and oily materials shall never be stored around oxygen; nor should oil or grease be applied to fittings.
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56. HANDLING & USE
After the regulator is attached, the cylinder valve should be opened just enough to indicate pressure on the regulator gauge (no more than one full turn) and all the connections checked with a soap solution for leaks.
Never use oil or grease on the regulator of a cylinder valve.
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57. HANDLING & USE
The following rules should always be followed in regards to piping:
Plastic piping shall not be used for any portion of a high pressure system.
Do not use cast iron pipe for chlorine.
Do not conceal distribution lines where a high concentration of a leaking hazardous gas can build up and cause an accident.
Copper piping shall not be used for acetylene.
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58. HANDLING & USE
A cylinder should never be emptied to a pressure lower than 172 kPa (25 psi/in2) (the residual contents may become contaminated if the valve is left open).
When work involving a compressed gas is completed, the cylinder must be turned off, and if possible, the lines bled.
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59. HANDLING & USE
When the cylinder needs to be removed or is empty, all valves shall be closed, the system bled, and the regulator removed.
The valve cap shall be replaced, the cylinder clearly marked as "empty," and returned to a storage area for pickup by the supplier.
Empty and full cylinders should be stored in separate areas.
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60. HANDLING & USE
Where the possibility of flow reversal exists, the cylinder discharge lines should be equipped with approved check valves to prevent inadvertent contamination of cylinders connected to a closed system.
"Sucking back" is particularly troublesome where gases are used as reactants in a closed system.
A cylinder in such a system should be shut off and removed from the system when the pressure remaining in the cylinder is at least 172 kPa (25 psi/in2).
If there is a possibility that the container has been contaminated, it should be so labeled and returned to the supplier.
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61. HANDLING & USE
Liquid bulk cylinders may be used in laboratories where a high volume of gas is needed.
These cylinders usually have a number of valves on the top of the cylinder.
All valves should be clearly marked as to their function.
These cylinders will also vent their contents when a preset internal pressure is reached, therefore, they should be stored or placed in service where there is adequate ventilation.
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62. TRANSPORTATION OF CYLINDERS
To protect the valve during transportation, the cover cap should be screwed on hand tight and remain on until the cylinder is in place and ready for use.
Cylinders should never be rolled or dragged.
When moving large cylinders, they should be strapped to a properly designed wheeled cart to ensure stability.
Only one cylinder should be handled (moved) at a time.
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