OSHA test #3
Hazard Identification
NFPA Diamond (ranges 0 to 4) *Red=flammability *Blue=health *Yellow=reactivity *White=special information
using fire extinguishers
PASS method *P-ull pin, A-im, S-queeze,S-weep
ergomonics common indicators:
b. methods of identification i. general observation ii. questionnaires and interviews iii. videotaping and photography iv. drawing and sketching v. measuring the work environment vi. challenges from age
examples of electrical hazards
bare wire...equipment that lacks UL label....equipment not properly grounded...working with electricity near water...static-electricity discharge
reducing electrical hazards bonding electrical equipment:
conductir cinnects two pieces of equipment reduces potential electrical diferences between equipment---reduces sparking potentail
medical management' repetitive strain injuries (RSI)
covers the number of CTDs caused by forceful awkward hand movements repeated frequently over time
detection systems flame detectors:
detection of fires at a distance (expensive)
ingestion
entri of substances through mouth
injection
entry of substances via needle or syringe
reducing electrical hazards 29 CFR 1910 (subpartS)
extracted from national electric code (NEC) 1. design of electrical systems 2. safety-related work practiced
electricity
flow of negatively charged particles, called electrons, through an electrically conductive material
Job Safety Analysis Step #2
i. break the job down into steps
System safety failure modes and effects analysis
i. calulate potential failure based on subsystems 1. excellent for determining optimum points for improvig and controlling product quality
job safety analysis Step#3
i. describe the hazards in each step of the task 1.use the information to eliminate and/or reduce hazards associated with the job 2. improve the system weaknesses that produced the hazard
elletrical shock
i. electrical current passing through theh body ii. quantity and path determines level of damage
System Safety predictive: "what if?"
i. identify possibility/probability of loss ii. required by OSHA (process safety regulation)
System safety fault tree analysis
i. identify unacceptable loss and reason back ii. OSHA's explation 1. a quantitative assesment of all the undersirable outcomes, which could result from a specific initiating event 2. it begins with a graphic representaion of all possible sequences of events that could result in an incident 3.the resulting diagramm looks like a tree with many branches- each branch listing the sequential events for different independent paths at the top 4. probabilities areea assigned to each event and then used to calculate the probabilityof occurrence of the undesired event
benefits of egonomics
i. improved health and safety for workers ii. higher morale iii. improved productivity iv. improved competitiveness v. decreased absebteeism/turnover vi. fewer injuries/illness
Harzard Identification:
i. job safety analysis(JSA) 1. throught observations 2. prevent future losses 3. make the job safer ii. system safty analysis 1. predict losses 2. alter potential outcomes
reudcing electrical hazards lightning:
i. lightning rods ii. avoid high places/tall objects iii. proper grounding iv. rubber clothing v. avoid cell /telephone use vi. avoid open windows/doors
Job safety analysis
i. makes all jobs safe and efficient through evaluation ii. evaluate each job step for: 1. hazards 2. efficiency (ergonomic conssideration 3. impact on quality iii. develop solutions for each for each deficiency 1. job hazard analysis(JHA) 2. total job anaysis (TJA) ( when ananlysis is comprehensive and includes more than hazards
system safety conclusion
i. many industries rely on comprehensive use of system safety, including: nuclear power plants, aero-space industry, chemical production facilites
ergomonics training and education:
i. potential riskis of injuries/illnesses ii. causes and symptoms iii. means of prevention iv. treatment
System safety back-up systems:
i. redundant 1. the same as the system it would replace in an emergency 2. example : spare tire, emergency lighting ii. "diverse" 1. supports the overall goals of a system but uses different technology 2. emaples: battery power ti run lights when main power goes out, cellphone when "land-line" fails
reducing electrial hazards types of grounding:
i. separate equipment grounding ii. ground fault circuit interrpter-- detects flow of current to the ground>opens the circuit>and interrupts flow of current
System Safety important concepts:
i. system life cycle ii. preliminary hazard reveiw 1. performed at design stage (matrix-similar to JSA) iii. failure modes and effects analysis 1. calculate potential failure based on subsystems iv. fault tree analysis 1. identify unacceptable loss and reason back
reducing electrical hazards static electricity hazards:
i. transfer charges to surfaces of lower potentail ii.bonding and grounding iii. raising humidity above 65% reduces charge iv. anti-static materials
Job Safety Analysis Step #1
i. watch work being done 1. what are some effective methods for watching work being down ? 2. why is it important to involve the employee?
hazard prevention engineering controls:
i. workstation design ii. design ofwork methods iii. tool design and handles
medical management cumulative trauma disorders (CTDs):
injuries that result from an accumulation of repetitive motion stress
fuses and circuit breakers
interrupt current flow when current is too high for wiring or equipment 1. sustained overload 2. short circuit equipment or wiring
toxic substances permissible exposure limit(PEL)
less conservative than ACGIH
sources of fire hazards classification of vapors: auto-ignition temperature
lowest point at which the vapors of a liquid or solid will self-ignite without a source of ignition
sources of fire hazards classification of vapors: flash point
lowest temperature for a fuel att which vapor concentrations are suffciently produced to flash in a source of ignition *flammables liquids <100F *combustible liquids >100F
sources of fire hazards classification of vapors: fire point
minimum temperature at which vapors will continue to burn, given a source of ignition
fire sprinkler types wet pipe system:
most common, fast response
combustion
products of combustion *fire gases *light (flame) *heat *smoke primary cause of loss of life: "inhalation of heated, toxic and Oxygen-deficient gases & smoke" *smoke is the visible sign of fire but it carries invisible poionous gases resulting in lung damage
types of electical hazards
short circuits. water. electrostatic hazards. arcs and sparks. combustible and explosive hazards. lightening hazards. improper wiring. insulation failure. equipment failure.
effects of toxic substances acute
sudden dose of a highly concentrated substance that results in immediate health problems ranging from irritation to death
ergonomics
the science of confirming the workplace and all of its elements to the workers *objective -minimize the physical stress associated with the workplace
The fire tetrahedron
three elements required tp start and sustain fire: 1. oxygen 2. fuel 3. heat 4. chain reaction eliminate 1 leg of the fire tetrahedron to extinguish
fire sprinkler types deluge systems:
used when damage form sprinklers can respond (example: large storage areas for flammable liquids)
fire sprinklers types pre-action:
used when damage from sprinkler water is a concern (alarm sounds when valve opens, before sprinklers activate)
fire sprinkler types dry pipe systems:
used where freezing is a concern
fire sprinklers combination system:
various combinations of pre-action, deluge, dry pipe, and wet pipe
industrial hygienist toxicology:
"the study of the nature and actions of poisons and their effects upon living organisms"
classes of toxic fire gases
* asphyxiants -- deprive the body of needed Oxygen *irritants *toxicants
Fire sprinklers-history
* invented in 1874 by American Henry Parmalee * until 1940s/50s, sprinklers were installed almost exclusively for protection of buildings (ex. warehouses and factories) *following several fires with significant loss life, fire & building offcials found automatic sprinklers had impressive life safety record
classes of fire/extinguishers: IMPORTANT
*Class A fires -"ordinary" combustibles (paper,cardboard) *Class B fires-flammable and combustible liquids and those plastics which melf in a fire *Class C fires-energized electrical equipment *Class D fires-combustible metals *Class K* fires- combustible cooking media-vegetable or animal oil and fats (not in text)
inhalation
*airborne substances inhaled through nose, throat, bronchial tubes,and lungs *hazards factors: --concentration --duration --breathing volume
toxic fire gases contain:
*carbon dioxide...(PEL 5000 ppm) *Carbon Monoxide...(PEL 50 ppm) *Hydrogen Cyanide...(PEL 10 ppm) *Acrolein...(PEL 0.1 ppm) *in addition to many others....
hazard communication standard requirements
*conduct annul survey of chemical inventory *check hazard labels (english( *verify current MSDSs on hand *ensure written program is in place *conduct periodic HazCom training
effects of toxic substances chronic
*continual exposure over time that results in health problems that developed slowly * conditions --limited concentrations --progressive accumulation --little/no awareness of exposure
methods for extinguishing:
*elimination of fuel ( starvation) *elimination of heat (cooling) -takes away heat, cool colids below ignition temperature, and cools liquids below flash point *elimination of O2 (smothering) -prevents cintact between fuel and O2 *interruption of chain reaction
Suppression systems
*fire extingushers *sprinklers
OSHA fire standards 29 CFR 1910 (SubpartL)
*fire protection *portable fire suppression equipment *fixed fire suppression equipment *other fire protection systems
detection systems heat detectors:
*fixed temperature-detects temperature changes *rate of rise-detects how fast temperature rises
sources of fire hazards: classification of liquids:
*flammable -liguid chemicals which can form an air-vapor mixture that can be ignited at room temperature *combustible-liquid chemocals which must be heated to form an air-vapor mixture capable of being ignited(or solid chemicals which will burn
Hazard Communication standard 29 CFR 190.1200
*identify hazardous materials in workplace *inform employees of these substances *methods: --container labeling --material safety data sheets (MSDS) --training
automatic fire sprinklers are:
*individuallyy heat activated *operate autpmatically in the area of fire origin *most fires can be handled by 1 or 2 sprinklers
toxic substances router of entry
*inhalation *absorption *ingestion *injection
fire sprinklers residential:
*opposed by NAHB *for new construction, system usually costs between $2.00 to $2.50 per square foot (less than the cost of carpeting) *concern for water damage *Fire Depts. use tens to hundreds times more water than a sprinkler system discharges
absorption
*passage of substances through skin *hazard factors --part of body --molecular size --degree of ionization --solubility
detection systems smoke detectors:
*photoeletric- smoke disturbs a light beam *ionization-radioactive material makes air conductive and detects when smoke has changed that conductivity
toxic substances factors:
*properties *dose amount amount *exposure level *route of entry *individual resistance
toxic substances exposure levels (ACGIH) --threshold limit values
*researched and updated by ACGIH *based on airborne concentrations of substances --measured air samples averaged over an 8 hour workday *repeater exposures at these levels should not produce adverse effects *ideally, based on studies of human exposure.
fire dangers to humans
*smoke --gases present are toxic to humans ( carbon monoxide --suffocation from oxygen deprivation *burns
sources of fire hazards fuel types:
*solids *liquids *vapors *gases
sources of fire hazards types of solids:
*wood *plastic *textiles *paper
detection systems gas detectors:
--detects low concentration of gases (highly sensitive) *examples: oxygen, sulfur dioxide, hydrogen sulfide, cyanide, ammonia, etc * CO detectors can detect the presence of a by-product of a fire
thermal circuit breakers
1. heat bends sensitive metal strip 2. thermal circuit breakers
fuses
1. metal strip that will melt 2. causes circuit to open at fuse 3. stop flow of current
magnetic circuit breakers
1. solenoid coil surrounds metal strip, connects to tripping device 2. magnetic force of solenoid retracts strip 3. opens circuit
reducing electrial hazards proper wiring:
3 parts: 1. hot wire 2. neutral wire 3. ground wire even if done improperly, equipment may work
electrical harzards to humans
a. current from i. voltage determines danger ii. natural skin resistance determines if current from can be overcome (example. skin moisture) iii. path offlow affects severity
ergomonics common indicators:
a. identifying problems i. apparent trends in accidents ii. incidence of CTDs iii. absenteeism and high turnover rates iv. employee complaints v. employee-generated changess manual material handling
reducing elecrical hazards
a.purpose i. safeguard people ii. reduce probability of fire iii. protect equipment example grounding electrical equipment-provides conducting path betwee equipmenT and earth