module 1: pertinent legislation module 2: definitions & terminology module 3: examples of...
TRANSCRIPT
Confined Space Entry
Module 1: Pertinent legislation Module 2: Definitions & Terminology Module 3: Examples of confined space injuries &/or fatalitiesModule 4: Overview of confined space hazards; hazard
identification & assessment processModule 5: Overview of control methods Module 6: Methods of analyzing, eliminating, & controlling
confined space hazardsModule 7: Personal protective equipment / Life Saving
EquipmentModule 8: Emergency planning
Table of Contents
Module 9: Legislated documentation requirementsModule 10: Oxygen deficiency & enrichment Module 11: Flammable gases / hot Work Requirements Module 12: Toxic atmospheres that are Immediately
Dangerous to Life or Health.Module 13: Occupational Exposure LimitsModule 14: Accident Incident ReportingModule 15: Hands on:
PPE/rescue equipmentSample permits/ Hazard AssessmentGas monitors
Table of Contents (cont.)
Often fatal consequences - catastrophicOften multiple injuriesFrequency of incidents is too highWould be rescuers become victimsIceberg principle - lots of incidentsGeneral lack of awareness & training“never happen to me” mentality
Why Train?
Aim for Excellence NOT Stupidity!
ALL workers who work within confined spaces must receive specific training. Examples of additional training in addition to confined space training:
Gas Testing Fall Protection training for vertical entry First aid/rescue planning
Training
ALL workers with related duties, such as rescue workers, supervisors, attendants and “fire watch" personnel must also receive training specific to confined spaces.
Training records must be kept. Refresher training to be considered.
an enclosed or partially enclosed space?
is it designed or intended for human occupancy?
Does it have restricted means of access & egress?
Can it become hazardous to a person entering it as a result of:
(i) its design, construction, location or atmosphere, or(ii) the materials or substances in it, or (iii) any other conditions relating to it.
4 questions need to be asked…
Needs to meet all of these criteria
What are Confined Spaces in Schools?
Apply the 4 CriteriaIs this a confined space ?
Apply the 4 CriteriaIs this a confined space ?
Apply the 4 CriteriaIs this a confined space ?
Is this a potentially hazardous space?
Apply the 4 Criteria
Apply the 4 CriteriaIs this a confined space ?
Apply the 4 CriteriaIs this a confined space ?
Trenches & excavations can be confined spaces, if there is a likelihood of hazardous gases, engulfment
and/or the lack of oxygen.
Worksafe Videos
Worksafe Videos
Worksafe Videos
September, 2009Section 511. Confined Space Entry(1) An employer shall assess the work area to determine whether it contains confined spaces.
(2) "confined space" means an enclosed or partially enclosed space that (a) is not designed or intended for human occupancy except for the purpose of performing work; (b) has restricted means of access and egress; and (c )may become hazardous to a person entering it as a result of
(i ) its design, construction, location or atmosphere, (ii) the materials or substances in it, or (iii) any other conditions relating to it.
(3) A worker shall not work in a confined space after January 1, 2013 unless he or she has completed a confined space entry program prescribed by the commission.
(4) An employer shall inform a worker who may have to work in a Confined space of a hazard by posting signs or other equally effective means of advising of the existence of and dangers posed by confined spaces.
Legislation
Legislation Section 512. Corrective precautions (1) Upon first entering a confined space, a worker shall assume the space is hazardous until the contrary is demonstrated.
(2) An employer shall ensure that a worker does not enter a confined space until (a) an adequate assessment of the hazards related to the confined space has been carried out; (b) a source containing a hazardous substance leading to the confined space is safely and completely blocked off or disconnected; (c) a test required under subsection (11) has been completed; (d) the worker is qualified to safely enter and perform duties within the confined space; (e) a written work permit documenting the tests and safety precautions has been completed (f) a set of written safe work procedures has been developed and a worker has been instructed in these procedures.
(3) The assessment referred to in paragraph (2)(a) shall be recorded in writing and shall consider, with respect to each confined space,
(a) the hazards that may exist due to the design, construction, location, use or contents of the confined space; and (b) the hazards that may develop while work is done inside the confined space.
Legislation (cont.)
(4) The record of the assessment may be incorporated into an entry permit.
(5) Where 2 or more confined spaces are of similar construction and present the same hazards, their assessments may be recorded in a single document, but each confined space shall be clearly identified in the assessment.
(6) The employer shall appoint a person with adequate knowledge, training and experience to carry out the assessment and shall maintain a record containing details of the person’s knowledge, training and experience.
(7) The assessment shall contain the name of the person who carries out the assessment.
(8) The person shall sign and date the assessment and provide it to the employer.
Legislation (cont.)
(10)The employer shall ensure that the assessment is reviewed as often as necessary to ensure that the assessment referred to in paragraph (2)(a) remains current.
(11)Appropriate tests for harmful vapours, gasses, fumes, mists, dusts or explosive substances and oxygen deficiency shall be made and recorded
(a) before entry into the confined space; (b) after an interruption in the work procedures; and (c) at appropriate intervals.
(12)Where a test made under subsection (11) indicates an unsafe condition, the confined space shall be ventilated or cleaned or both and periodically retested to ensure that: (a) the oxygen content is between 20% and 22%; (b) the concentration of flammable substances is maintained below 10% of the lower explosive limit (LEL ) of that substance or substances; and (c) a worker's exposure to harmful substances is maintained at acceptable levels in accordance the TLVs established by ACGIH.
Legislation (cont.)
Legislation (13) Where gas tests indicate harmful or explosive substances and it is not feasible to provide a safe respirable atmosphere, an employer shall ensure that :
(a) entrants wear respiratory and personal protective equipment appropriate to the hazards; and
(b) where a flammable or explosive gas or liquid is present all sources of ignition are controlled or eliminated.
(14) Where control measures cannot be implemented, a worker shall leave the confined space.
(15) Gas tests made shall be performed by a person who has been adequately trained in the proper use of testing equipment.
(16) Equipment used in testing and monitoring shall be calibrated and monitored according to the manufacturer's instructions.
(17) The completed permit shall be available at the time of entry to all authorized personnel by posting it at the entry portal or by another effective means.
Legislation (cont.)
Legislation Section 513. Work procedures
(1) If an entrant may be exposed to a harmful atmosphere or may become entrapped by material (a) wears appropriate retrieval equipment for rescue; and (b) has a life-line attached to the retrieval equipment which is tended at all times by a person, stationed outside the entrance able to effect rescue.
(2) the use of a lifeline is not required where an obstruction or other condition makes its use impractical or unsafe but, in that case, an employer shall implement procedures to ensure the safety of the worker.
Legislation (cont.)
(3) Entrants require attendants (b) stationed outside and near
i) the entrance to the confined space, or if there is more than 1 entranceii) near the one that best allows the attendant to perform their duties;
(c) is in continuous communication with the worker as per safe work procedure; and (d) is provided with a device for summoning an adequate rescue response.
(4) An attendant shall not enter a confined space and shall, in accordance with the required safe work procedure, (a) monitor the safety of the worker; (b) provide assistance to entrants and rescuers; and (c) summon an adequate rescue response where required.
Legislation (cont.)
Section 514. Entry into confined space
A confined space shall be entered only where (a) opening is sufficient to allow safe passage of a person wearing PPE/safety equipment; (b) mechanical equipment in the confined space is
(i) disconnected from its power source, and (ii) locked out and tagged;
(c) pipes & other supply lines with hazardous contents are blanked off; (d) measures, where appropriate, to continuously ventilate space; (e) liquid / free-flowing solid capable of drowning / entrapping have been removed; (f) adequate explosion-proof illumination is provided where appropriate; and (g) adequate barriers are erected to prohibit unauthorized entry.
Legislation (cont.)
45. (1) A worker may refuse to do work that the worker has reasonable grounds to believe is dangerous to his or her health or safety, or the health and safety of another
person at the workplace (a) until remedial action has been taken by the
employer to the worker's satisfaction; (b) until the committee or worker health and
safety representative has investigated the matter and advised the worker to
return to work; or (c) until an officer has investigated the matter
and has advised the worker to return to work.
OHS-ACT Right to Refuse to Work
program should meet regulationsprogram needs to be reviewedInform them of your hazard assessmentEnsure they use sop’s/permitsEmergency response planningPeriodically auditincident reporting system – “incidents don’t become accidents”
Owner Requirements Outside Contractors
5 %
15 %
Methane in Air
LEL
UEL
Too rich
Too lean
Competent - in relation to a person, means adequately qualified, suitably trained and with sufficient experience to safely perform work without supervision or with only a minimal degree of supervision;
Explosive atmosphere - means an atmosphere that(a) contains a substance in a mixture with air, under atmospheric conditions and at a concentration between the substance's lower explosive limit and upper explosive limit,
Hazard - means a situation, condition or thing that may be dangerous to the safety or health of workers;
Common Terms
Risk – likelihood hazard becomes incident; based on severity, frequency, duration, etc
Hot work - means work in which a flame is used or sparks or other sources of ignition may be produced, including
(a) cutting, welding, burning, air gouging, riveting, drilling, grinding, and chipping,
(b)using electrical equipment not classified for use in a hazardous location, and
(c) introducing a combustion engine to a work process;
Common Terms (cont.)
Flash point: Minimum T of which a liquid fuel is heated to give off sufficient vapor to form an ignitable mixture with air (i.e burns)
Ignition T: Minimum T req’d for substance to be heated to achieve self sustaining combustion independent of ignition source
Flammability Terms
Fire triangle
Ignition source
Lower flammable limit/flammable range
Flash Point/Vapor Pressure
Vapor density
Fire Triangle-Tetrahedron
Lowest conc. of flammable gas/vapor, expressed in % volume in air, that will burn or explode in presence of ignition source.Below this level, atmosphere is too lean to burn.
LEL is lowest part of the flammable range; upper limit is the UEL
5 %
15 %
Methane in Air
LEL
UEL
Too rich
Too lean
Lower Limit (LEL)
Flammable vapors exist above volatile liquids
such vapors are heavier than air and settle in low spots; travel large distances & ignite
Gas testing not enough; remove all liquids, residues, sludge
MSDS: look at flash point, vapor pressure, LEL, boiling point, vapor density
Flammable Liquids
Worker not to stay in Confined Space if:
> 25%LEL for inspection only; no source of ignition;
> 10%LEL - cold work;
> 5% LEL &/or > 23% O2 during hot work;
Section 515 – Explosive Atmospheres
hydrogen
Chlorine, benzene, gasoline
argon, carbon dioxide
Ammonia, methane
Air, carbon monoxide, nitrogen
propane
Light gases
Heavy gases
Vapor Density
Air = 1
System to ID all hazards existing in absence of controls; control minimizes risk
Every CS hazardous unless determined otherwise by risk assessment
Take into account: Routine & non-routine activities in & out of spaceFacilities & activities of adjacent spaces/workplaceContents and supply lines into/out of the space
Hazard Identification
Engulfment or entrapment by liquids/materials
Potential for fire or explosion, oxygen deficiency
Biological hazards – crawl spaces
Physical hazards- Temperature - Noise - Humidity
- Lighting - Ergonomics
Flammable residues - fire resistant coveralls ineffective
Toxic hazards – lead, asbestos, VOC’s, etc
Hazard Identification Process
a) Eliminate hazard
b) Substitute hazardous materials, processes, equipment
c) Engineering controls
d) Administrative controls
e) PPE-selection, use & maintenance
Best Option
Least Preferred option
Risk Assessment
Most confined spaces are designed to hold substances such as liquids, gases, and loose materials, or to house equipment.
Though they come in many sizes and shapes, most can be classified in one of two ways:
1. Spaces that are open-topped and have depth• pits • well • bins
2. Spaces with narrow openings• pipes • utility vaults• Attics • HVAC
Classification of Confined Spaces
a) Entrant is the person who enters a confined space.
b) Attendant stays outside the confined space, monitors the space, responsible for assisting the entrant, summons assistance in emergency.
c) Safety representative (or entry supervisor) is the competent person who assesses the hazards, lists necessary equipment and control measures, controls Confined Space Entry Permit process.
Confined Space Entry Definitions
Remain alert outside space
summon help if needed but do not enter
Consider activities outside space
Maintain 2 way communication
Know hazards posed & work requirements
assess conditions/changes that may impact entrants
Ensure controls measures working properly
Initiate emergency procedures as per sopPerform non-entry emergency rescue if safe to do so
Attendant
Remain alert at all times
Aware of all potential hazards
Aware of symptoms & warning signs of exposure
Report concerns to attendant
Exit immediately if conditions warrant, alarms sound, or if directed
You have a right to be made aware of all potential hazards
Entrant
Assessment must be carried out by a qualified person, and form completed
Must identify existing and potential hazards
Must contain name of person performing assessment
Must be signed and dated
Must be copied to Occupational Health and Safety Committee
Must be recorded and maintained in filing system
Has been separated into sections for ease of use
Hazard Assessment Form
1. Access into the confined space
2. Internal configuration and features of the confined space
3. Electrical hazards
4. Mechanical hazards
5. Engulfment Hazards
6. External Hazards
Assessment Form Sections7. Communications
8. Ventilation
9. Adverse temperatures
10. Noise / Vibration
11. Chemical Hazards
12. Other Considerations
Entrance/Exit Accessibility and ConfigurationEntrance/exit easily accessible?Type: Round, Oval, Square, Other?
Vertical Entry/ExitStairs, Fixed ladder, Portable ladder, Other?Condition?Tripod to be used?
Horizontal Entry/ExitElevated entry/exit?Work platform provided?
1. Access into Confined Space
Use & Shape of a space can create hazardous conditions:
Low Ceilings?Walk inErectStooped
Head Hazards?
Footing inside space?Narrow areas entrapping entrant/rescuerSloping surfaceUneven surfaces & bends
create challenges for attendant to communicate
Need to protect openings with barricades
2. Internal Configuration and Features
Other Internal features of space?Wet or slippery surfacesPoor lightingSharp objects Mold
Pipelines going through the space?
Use of ladders & scaffolding?
Need to protect openings with barricades
2. Internal Configuration (Cont.)
Possible contact with energized conductors?Controls: Lockout procedures, GFCI’s, grounding & bonding, double insulated tools
Hazardous sources:
- Broken/energized lighting & power- Damaged cords- Welding equipment not grounded/bonded
- Wet surfaces confound problems- Explosion/vapor proof lighting may
need to be assessedCSA C22.1 Canadian Electrical Code Part 1 Safety Standard for Electrical Installations, Clause 18 “Hazardous Locations”
3. Electrical Hazards
Unguarded mechanical equipmentExamples:
Moving/rotating belts or chains, gears, paddles, blades, shafts, pinch points
Lockout / Tag-out procedures required
4. Mechanical Hazards
Chemical?Sludge/sewage?Other hazardous liquid (water)?
Lock out and/or Isolate: physically prevent and/or disconnect pipes & energy sources by applying controls:
5. Engulfment Hazards
Such as:Locks,Tags,Blanks & blindsDouble block & bleed
Traffic hazard?
Parking lot (loading area/parking spaces in vicinity)?
Precipitation?
Overhead electrical wires
Spill or possibility of objects falling into opening?
6. External Hazards
Space has configuration that will hamper ventilation/purging?
Convoluted space?
Large volume?
Other?
7. Ventilation
Entrants can be visually observed by attendant?
Voice only adequate?
Visual hang signal adequate?
Internal telephone available?
Cell phone required?
Radio required?
Intercom?
Rope Signal?
8. Communications
Heat stress?
Cold stress?
9. Adverse Temperatures
Too loud?
PPE required?
Anti-vibration tools?
10. Noise / Vibration
Pipes/lines?Accumulation of:
Flammable/combustible/oxygen enrichedOxygen deficient atmospheresToxic atmosphere
Oxygen deficiency can be caused by:Consumption: oxygen is used up (respiration, fire, bacterial action)Displacement: heavier materials push out normal air (argon, CO2,
freon) .Reaction: air reacts with other materials to make other
compounds (oxidation-rust).
Combustion uses up O2 faster than respiration
11. Chemical Hazards
Symptoms of Oxygen DeficiencyPercent of Oxygen in Air Symptoms in workers
20.9% Normal Air, NO Symptoms
19.5% Minimum allowable level
18% Early symptoms, Decreased ability to work
16% Increased heart and lung rate
14% Impaired judgement and coordination , FatigueLoss of peripheral vision
12% Nausea and Vomiting, Extreme Fatigue
Less than 10% Nausea and Vomiting, unconsciousness, convulsions, death
11. Chemical Hazards (cont.)
Does lack of oxygen cause shortness of
breath?
Are there adequate
warning signs of oxygen
deficiency?
11. Chemical Hazards (cont.)
Symptoms of Oxygen Deficiency
Oxygen EnrichedLevels above 21%.
flammables & combustibles burn faster & harder
Don’t use pure oxygen to ventilate.
Don’t store oxygen tanks/hoses in a confined space
Wear fire resistant clothing
11. Chemical Hazards (cont.)
Flammable liquids
11. Chemical Hazards (cont.)
Flammable vapors - above liquid surface often heavier than air (lower tank region)
Vapors can reach great distances to ignition sources
Fire prevention:Remove all hydrocarbons, vapors & flammable gases from tanksEliminate ignition sources Properly ventilate space to dilute vapors
Chemical ToxicityChemicals bought into space
Fugitive emissions (welding, solvents, degreasers)
Waxy surfaces (hydrocarbons)
No magic meter to test all chemicals
Need to refer to MSDS’s & hazard assessment
Consider skin & inhalation hazards
11. Chemical Hazards (cont.)
Immediately Dangerous to Life and Health (IDLH)
Used for purpose of respirator selection
11. Chemical Hazards (cont.)
Airborne levels of hazardous substances that may:
Impair the worker's ability to safely leave the dangerous situation
Lead to irreversible or delayed health effects, serious injury, or death in a short period
ACGIH TLVs - Time Weighted AverageTWA = Concentration at which workers can be repeatedly exposed day after day without adverse health effects
Can exceed TWA from time to time as long as average exposure not exceeded
Some chemicals require us to be concerned even for short term exposures
STEL (Short Term Exposure Limit)Ceiling limit
11. Chemical Hazards (cont.)
Carbon MonoxideFormed by incomplete combustionColorless, odorless gas, non irritatingSlightly lighter than airCauses suffocation without warningGo unconscious at high concentrationsLEL = 12.5%, TWA=25 ppmNIOSH IDLH = 1200 ppm Sampling: gas meter or colorimetric tubesTypical respirator not adequate
11. Chemical Hazards (cont.)
Hydrogen SulfideSewer gas –rotten egg smell-organic breakdownColorless, flammable gas at high concentrationsTLV=10 ppm; STEL=15 ppm; NIOSH IDLH=100 ppmNatural component of crude oil (heavy/sour crude)Paralyzes sense of smell (can’t rely on smell)heavier than airMutligas meter or colorimetric tubes
11. Chemical Hazards (cont.)
Chlorine - Chlorinators3 forms: liquid (4 %); solid (12 %) & gas 100 %Pungent irritating corrosive gasUpper respiratory & eye irritationHeavy gas (Vapor density > air)Ventilate at low levelsTLV-TWA = 0.5 ppmTWA-STEL = 1 ppm (15 minute)Colorimetric tubes
11. Chemical Hazards (cont.)
Air MonitoringAssesser must be competent Calibrate monitors Remote sampling first, then enterReassess to ensure conditions stay safe
before entry; after break in work; & at appropriate intervalsIf tests indicate unsafe condition; ventilation &/or clean & retest so that:
O2 is between 20 & 22 %< 10 % LFLACGIH TLVs not exceeded
Permit to be posted at portal entry (with gas testing results)
11. Chemical Hazards (cont.)
How to test?
Need to test remotely first at least 3 different levels to see if results vary
vapor density is important
Hint: test exhaust air
sludge can give off volatiles if heated or disturbed
11. Chemical Hazards (cont.)
Air Monitoring Cont’dPass or fail scenarioNot looking for 100 % accurate readingsUse portable fairly accurate instruments
gas meter – oxygen, LEL, CO, H2S, colorimetric tubes – , Cl2, CO2,, NO2, etcPID – TVOC’s (hydrocarbons)
Is it safe or unsafe for entry!
11. Chemical Hazards (cont.)
Calibration vs. Bump Test
Calibration - gases of known concentration verify instrument is measuring properly (quantitative test)
Bump test – a short burst of gas to ensure that sensors and alarms are working (qualitative test)
11. Chemical Hazards (cont.)
Detector TubesNumerous Toxic Gas/Vapors
Chemical reactions colored reagentLength of colored stain = concentrationPump (draws 100 ml) Need to follow instructionsSimple procedure but limitations + interferencesAccuracy: + or – 30 %Draeger, Gastec, Kitigawa Need to know contaminant of concernGrab samples only
11. Chemical Hazards (cont.)
Photo-ionization DetectorReal time measurements of TVOC’s
Universal detector (not selective)
Very sensitive (volatile toxics & flammables)
11. Chemical Hazards (cont.)
Structural integrity?
Rodents/animals?
12. Other Considerations
Confined Space Hazard Assessment Form
Assessment Form (cont.)
Hazards found in confined spaces can be placed in the following groups:
a.) Oxygen deficient atmospheres can be caused by rusting of a steel vessel, any form of burning (including welding & brazing), absorption by grain or soils, and consumption by bacteria.
b.) Asphyxiant gas physiologically inert gases can dilute or displace atmospheric oxygen below the level required for normal human functioning examples of asphyxiant gases are carbon dioxide, ethane, helium, hydrogen, methane, and nitrogen.
c.) Toxic atmospheres - containing gases, vapours, dusts or fumes that have poisonous effects on the body. Cleaning, painting or welding may produce dangerous vapours or fumes. Gases such as hydrogen sulphide may leak into or be released from sludge present in the confined space. Carbon monoxide may be generated in the space by an internal combustion engine. Methane may be created through the fermentation of plant material in the space.
Confined Space Hazards
d.) Flammable or explosive atmospheres - containing flammable gases, vapours or dusts that could be ignited by a spark or open flame. The risk of explosion increases if an oxygen enriched atmosphere is present.
e.) Engulfment - workers can be trapped or buried by dry bulk materials such as grain, sand, flour, fertilizer and sawdust.
f.) Operation of moving parts being trapped or crushed by augers, mixers, agitators, or conveyor belts.
g.) Uncontrolled introduction - of steam, water or gas
h.) Other hazards - these could result from the work being done Examples are noise, extremes of temperature, radiation, manual handling and falls.
Confined Space Hazards
Any situation involving the risk of fire or explosion is considered to be a “hot work” hazard situation, if the work being done could generate a spark. Common hot work hazards would include, but are not limited to:
cutting - weldingburning - air gouging
riveting - drillinggrinding - chippingthe use of non-classified electrical
equipmentplacing a combustion engine in the
confined space
If a hot work hazard situation exists, a special hot work hazard safe work permit must be issued.
“HOT” Work
Noise Confined space can amplify sounds Noise
interferes with essentialproduced by tools and equipment. communication between entrants and attendants.
Falling objects Objects fall into the space because topside openings are unguarded or improperly guarded.
Extreme temperatures The space's location and equipment make it hot or cold
Environments put workers at risk. equipment it contains make it ideal for heat stress, doing strenuous work or wearing protective clothing make tasks more difficult to accomplish
Slippery Surfaces Leaks, spills and condensation make walking surfaces slippery
Wet surfaces are usually slippery. They increase the risk of falls.
Confined Space Complications
Methods used to control hazards found in confined spaces fall into three categories:
1.) Engineering controls - ex. ventilation systems
2.) Administrative controls - ex. entry permit system
3.) Personal protective equipment ex. supplied air breathing apparatus
Engineering controls are designed to eliminate the hazard administrative controls and personal protective equipment try to minimize the hazard.
Hazard Control Methods
a) Eliminate hazard
b) Substitute with other materials
c) Use engineering control measures
d) Use administrative controls
e) PPE
Hierarchy of Controls
Once an existing or potential hazard is identified, an employer is required to eliminate the hazard or if elimination is not reasonably practicable, control the hazard.
If reasonably practicable, an employer must eliminate or control a hazard through the use of engineering controls.
If this can not be done, the employer must use administrative controls that control the hazard to a level as low as reasonably achievable.
If engineering and administrative controls will not control the hazard, then an employer must ensure the appropriate personal protective equipment is used by workers affected by the hazard.
Eliminating and Controlling Hazards
The following are examples of practices used to eliminate and control atmospheric confined space hazards.
Cleaning the space to remove contaminants. For example: use a vacuum and hose to remove petrochemical sludge,
Replacing an unsafe atmosphere with clean respirable air by purging and ventilating
Replacing the unsafe atmosphere before entry usually involves mechanical ventilation to blow or suck fresh air in and continuously move it throughout the space.
Atmospheric Hazards
Preventing fires and explosions. Fire prevention requires control of the three elementsneeded for a fire or
explosion
Inerting the confined space. Inerting is used to eliminate hazards such as chemical reactions, flammable vapours, and the possibility of explosions.
Using continuous ventilation to keep the atmosphere safe.
Atmospheric Hazards (cont.)
Physical Hazards
Loose and unstable material.
Shoring of unstable trench or evacuation walls
Removal of unstable material from confined space before entry.
Requirement for lifeline and harness and provision for immediate rescue of a worker in distress.
Moving parts of machinery.
Locking out. The use of a Lock or locks to render machinery or equipment inoperable or to isolate an energy source.
Electrical Hazards
Substitute pneumatic tools for electrical ones.
Properly grounded tools.
Double-insulated tools.
Use of ground fault circuit interrupter.
The type of PPE to be worn will depend on the job to be done and the hazards that have been identified. PPE considered basic for almost any job are:
Employees are responsible to ensure their PPE is clean, properly maintained, in good serviceable condition, CSA approved, and suitable for the type of work to be performed.
Basic Personal Protective Equipment
approved safety footwear gloves hard hat safety glasses flame retardant coveralls
Determined by hazard /risk assessment- based on hazards
Noted on entry permit
Protective clothing: chemical (corrosive/toxic) & flame resistant (residues)
Need to consider hazardous materials (mold, asbestos, lead)
Hydrocarbon stained coveralls can affect fire resistant clothing
Garments: chemical resistance, appearance, comfort
Among the more widely used fibers for protective clothing are NOMEX, INDURA and FLAMEX.
Personal Protective Equipment
Mechanical filters – NRP – 95,99,100
Chemical cartridges – OV, AG
Combination of OV/AG/HEPA
Negative (+) pressure field check
Qualitative fit test
CSA program & training – CSA Z94.4“Selection Care & Use”
Don’t protect against oxygen deficiency
Air Purifying Respirators
Selection of respiratory protective equipment depends on the type of work and the hazards to be encountered. There are three main types of respiratory protection devices:
1. Dust Masks - these masks may be disposable or reusable and are designed to filter out certain particles, mists and some fumes.
2. Canister or Cartridge - cartridge respirators can only protect you against the specific hazard(s) and specific concentration levels as identified on the canister/cartridge. The canister or cartridge respirator has limited use in confined space entry work.
3. Supplied Air - these devices are designed to supply fresh air from an independent and safe source.
Respiratory Protective Equipment
written program with worksite-specific procedures when respirators are necessary
provide necessary training on selection, use, care & limitations and medical evaluations as per CSA Z94.4
Program elements:1. Selection 2. Medical evaluation3. Fit testing 4. Use5. Maintenance and care 6. Breathing air quality and
use7. Training 8. Program evaluation
Respirator Program
Air-Supplying RespiratorsDeliver a safe supply of breathing air from a tank or an uncontaminated area nearby.
Supplied Air Breathing Apparatus (SABA)The SABA has a positive pressure face mask connected by an airline to a cylinder of compressed breathing air not carried by the worker. For safety purposes, the SABA comes equipped with an egress bottle of air which is carried by the worker. This bottle contains a maximum of five minutes of air supply. In an emergency the worker disconnects the air line and turns on the egress bottle. SABA respirators are commonly used when the work to be performed will take several hours.
Supplied Air Apparatus
Self Contained Breathing Apparatus (SCBA)The SCBA has a positive pressure face mask connected to a compressed air cylinder which is carried by the worker. This type of equipment provides a limited air supply. Due to this limitation, SCBA respirators are best suited to perform short term and emergency tasks.
The amount of air supply possible will be affected negatively by many factors including:• condition of the equipment• was it filled properly• temperature bottle was filled at versus temperature it will be used in• physical condition of the person using the SCBA• physical size of the person using the SCBA• workers emotional state and experience level• exertion level required of worker
Supplied Air Apparatus
The emergency response plan must include the emergency procedures to follow in the event of an emergency, including procedures to evacuate the confined space immediately if:
• an alarm is activated• the concentration of oxygen inside the confined space
moves outside of the acceptable range• there is a significant change in the amount of hazardous substances inside the
confined space.
Plan must be in writing & explained to entrants
Emergency Response
Emergency response plans must include the following:• the identification of potential emergencies,• procedures for dealing with the identified emergencies,• the identification of, location of and operational
procedures for emergency equipment,• the emergency response training requirements,• the location and use of emergency facilities,• the fire protection requirements,• the alarm and emergency communication requirements,• the first aid services required,• procedures for rescue and evacuation, and• the designated rescue and evacuation workers.
The Emergency Response Plan
Additional items that you may want to include in a rescue plan are:
• dimensions of the space, location of entry and exit points, and obstacles to removing an injured worker,• possible hazards that may arise during rescue, the appropriate evaluation of these hazards, and control methods recommended by the qualified person, and• rescue methods for a worker who is unconscious (on or off of a lifeline), or distressed.
Drills must be carried out periodically
The Emergency Response Plan (cont.)
1. Self rescue: entrant capable of exiting unassisted 2. External rescue: need outside assistance without additional
entry; opening & path unobstructed to allow external Retrieval system (already set up).
3. Entry rescue: entrant needs assistance to escape; but opening &/or path obstructed, or entrant needs to be assessed/helped before moving them
4. IDLH entry rescue: unknown atmosphere or immediately dangerous to life & health condition. Time is critical. Principle: “life over limb” is allowed.
Types of Rescue
Internal or externalNot become victims themselves-assess-sop’sReady to respond when notified minutes for IDLHTrained and properly equippedLocate the entrant(s), stabilize them, package & extract themEnsure proper first aid equipment on site
Emergency Response Group
Worksafe Video
For every confined space entry, an employer must designate a competent worker to be in communication with a worker in the confined space. The “tending person” does not have to be immediately outside the confined space unless the following point comes into play.
* the oxygen content of the atmosphere inside the confined space is Less than 19.5% or greater than 23.0%
* a hazard is identified by the hazard assessment and the hazard cannot be eliminated or effectively controlled.
Tending Worker
The role of the tending worker is to monitor the safety of the person(s) working inside the confined space and to take action if an emergency arises. This tending worker must:
• keep track at all times of the number of workers inside the confined space
• be in constant communication with the workers inside the confined space,• have a suitable system for summoning assistance, and• not leave the area until all workers have left the confined space or another tending worker is in place.
Tending Worker (cont.)
A safe work permit is a document that identifies the work to be done, the hazard(s) involved, and the precautions to be taken. It ensures that all hazards and precautions have been considered before work begins. Safe work permits should always be used when work is performed by an outside agency or employer.
What is a safe work permit?• A safe work permit is a written record that authorizes specific work, at a
specific work location, for a specific time period. Permits are used for controlling and coordinating work to establish and maintain safe working conditions. They ensure that all foreseeable hazards have been considered and that the appropriate precautions are defined and carried out in the correct sequence.
• Employers are required to provide workers with a safe place of work and to identify known safety hazards. This can be partly achieved through the use of a safe work permit system.
Safe Work Permit
There are two types of safe work permits.
1. Hot Work PermitHot work permits are used when heat or sparks are generated by work such as welding, burning, cutting, riveting, grinding, drilling, and where work involves the use of pneumatic hammers and chippers, non-explosion proof electrical equipment (lights, tools, and heaters), and internal combustion engines.
2. Cold Work PermitCold work permits are used in hazardous maintenance work that does not involve "hot work". Cold work permits are issued when there is not reasonable source of ignition, and when all contact with harmful substances has been eliminated or appropriate precautions taken.
Safe Work Permit (cont.)
A confined space entry permit is essentially a document that sets out the work to be done and the precautions to be taken.• It can function as a safety checklist to make sure that nothing is overlooked.• A worker must not enter a confined space at a worksite without a valid entry permit.• The entry permit must, at a minimum:
– List the name of each worker who enters the confined space and the reason for their entry
– Provide the location of the confined space,– Specify the time period for which the entry permit is valid– Take into account the work being done in the confined space, and therefore
the safety precautions that must be taken, and take into account the code of practice requirements for entering, being in and Leaving the confined space.
– The completed, signed permit must be kept readily available– If an employer performs a hazard assessment of a representative sample of
identical confined spaces, then a single entry permit can be used for these and any additional identical confined spaces
Entry Permit System
Location and description of confined space:Reason for entry:Permit issued to:Supervisor’s Name:Attendant’s name:Permit issuer’s name:% oxygen: % lower explosive limit: ppm CO: H2S:
Requirements
Emergency Rescuer yes noContinuous Gas Monitor yes noBarrier for ground openings yes noWarning Signs yes no
Confined Space Entry Permit
The entry log is a document kept by the Safety Watch (Monitor). It is an up to the minute running account of the personnel inside the confined space. Recommended information includes:
• the name of each worker• their personal protective equipment• the time the confined space was entered• the time the confined space was exited, and• the total number of workers in the confined space.
Confined Space Entry Log
Oxygen Deficiency• A worker enters an enclosed area and collapses. Another worker
rushes in to rescue the first worker. Both workers die. A worker enters a confined space. When he doesn't come out, a co-worker goes after him. A third worker tries to hold his breath and rescue both. All three workers die.
Can I tell if the air doesn't have enough oxygen?• NO! Air that is low in oxygen has no warning properties. You
can't smell, taste, or see any difference. By the time you feel faint or dizzy, you may not have enough energy or alertness to escape
Oxygen Deficiency
• Oxygen is used up when metals rust.
• Oxygen is used up during combustion - for example, by propane space heaters, during cutting and welding, and by internal combustion engines,
• Oxygen is replaced by other gases used in industrial processes for example, welding gases or gases forced into the space to prevent corrosion.
• Oxygen is replaced by gases leaking into an enclosed space through drains or other openings.
• Micro-organisms use up oxygen - for example, in sewer lines and fermentation vessels.
The only way to know what the oxygen level is in the atmosphere is to test for oxygen levels with a properly calibrated oxygen tester.
Oxygen Deficiency (cont.)
Inerting is the process of intentionally replacing the atmosphere inside a confined space with an inert gas such as nitrogen. Inert means that the gas will not react or cause an explosion or fire.
Inerting creates an oxygen deficient atmosphere because the air (with its oxygen) has been replaced by another gas.
Inerting is used to eliminate hazards such as:• chemical reactions• flammable vapours• the possibility of explosions• to prevent oxidation (rusting) of equipment or the walls of the confined space
Inert Atmospheres
Carbon Monoxide Gas (CO) - CO usually comes from the exhaust of gasoline engines and it is both odourless and colourless. Ringing in the ears, nausea, headaches and sleepiness are common symptoms of carbon monoxide poisoning.
Gasoline - Gasoline is in such wide spread use by the general public and industry that gasoline vapours are likely to be found almost anywhere. The average person can smell gasoline at 10 ppm.
Other toxic gases commonly associated with confined space entry are:• Ammonia• Chlorine• Carbon dioxide• Benzene • H2S – Hydrogen Sulphide• Vapours of the toxic component in cleaning products being used in the
confined space
GASES
Lower Explosive Limit is defined as "the minimum concentration of combustible gas or vapour in air, expressed as a percentage by volume, which will ignite if a source of ignition is present". Below this Level the mixture is too Lean to ignite (there is not enough of the gas or vapour present to form an explosion hazard).
In contrast, the Upper Explosive Limit, "the maximum concentration of combustible gas or vapour in air, expressed as a percentage by volume, which will ignite if a source of ignition is present". Above this level the mixture is too rich to ignite (there is too much of the gas or vapour present or too little air to form an explosion hazard) .
LEL and UEL
Occupational Exposure Limit• The maximum airborne concentration of a substance a worker
may safely be exposed to for an eight hour period.
Short Term Exposure Limit• The maximum allowable exposure of a toxic substance a worker
may safely be exposed to over a 15 minute period. Regulations allow only four 15 minute exposures per day with at least one hour between each exposure.
OEL & STEL
Report all hazardous occurrences – spvsrComplete Hazardous Occurrence reportNot to find blame but to learn from themLessons learned new sop’s
Most fatalities investigated reveal long term deficiencies/incidents
before fatal event !
Incident Investigation
Purpose: prevent 02 deficient, toxic & flammable atmospheresSome sources: 1/3rd the volume of CS per minute for low level contaminantsVentilation: primary means to control toxic airAir testing determines actual ventilation requirementsmechanical ventilation: 2 types –
General supply & exhaust & local exhaustNatural ventilation is not reliableMore efficient to push air than to pull airtest CS before and after introducing ventilation
Ventilation Requirements
Ventilation Requirements (cont.)
In CS not allowed without special Hot Work permitsign off req’d by safety officer & supervisorLocal exhaust at source General dilution – minimum 2000 cfm/welderHEPA/P100 respirators as minimumfire resistant clothingSpecial air monitoring requirements
Welding
Assessments
Assessments
Assessments
Assessments
Assessments
Assessments
Questions?