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LEARNING OUTCOMES (I). classification of occupational health hazards (physical, chemical, biological, ergonomic)commonly occurring occupational diseases and conditions arising from exposure to physical, chemical, biological and ergonomic hazardsmeaning of terms; toxic, harmful, corrosive, irritant and the response of the body to substances with these properties.
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1. NEBOSH NATIONAL GENERAL CERTIFICATE Occupational health hazards
3. LEARNING OUTCOMES (II) the main routes of entry of hazardous substances into the body
the significance of the form taken by a hazardous substance ie gas, vapour, mist, aerosol, smoke fume, dust, liquid and solid
the concept of target organs and target systems
occupational exposure limits; distinction between MELs and OESs
4. LEARNING OUTCOMES (III) general principles and methods of air monitoring
methods that can be used for prevention and control of hazardous substances, with particular reference to workplace ventilation systems
main requirements of the Control of Substances Hazardous to Health Regulations 1994
precautions needed during the storage, transport, use and disposal of dangerous substances
5. GENERAL ASPECTS OF OCCUPATIONAL HEALTH & HYGIENE what types of agent might represent an occupational health risk in the workplace?
how do we go about evaluating the severity of the risk?
6. PRINCIPLES OF OCCUPATIONAL HYGIENE Recognition/identification of occupational health hazards
Measurement of level or concentration
Evaluation of likelihood and severity of harm
Control strategies available to reduce or eliminate risk
7. RECOGNITION chemical
liquids, fumes, mists vapours, gases, dusts
physical
radiation, noise, vibrations, temperature, humidity
biological
bacteria, viruses, fungi
ergonomic
body position, repetitive actions, work pressure
8. CHEMICAL HAZARDS absorption then attack on organs or metabolic processes
toxic response
carcinogenic response
contact then attack on the surface of the body
corrosive/irritant response
dermatitic/sensitisation response
9. BIOLOGICAL HAZARDS exposure to biological agents resulting in illness
types of biological agent include
bacteria
viruses
fungi
10. PHYSICAL HAZARDS harmful energy absorbed by the body’s structure
energy derived from
mechanical sources
noise, vibration
radiation sources
ionising, non-ionising
thermal sources
11. ERGONOMIC HAZARDS concerns the physical, physiological and psychological relationships between people and work
specific areas include
perceptual responses
work rates and fatigue
man-machine interface
anthropometrics
12. MEASUREMENT continuously
control strategy where the risk is high
intermittently
initial determination of hazard
spot measurement in an established process
routine check measurement
13. EVALUATION harmful characteristics of the substance, energy or condition involved
concentration, intensity or level of the exposure to the harmful agent
time duration of the exposure
14. CONTROL elimination
substitution
change of work method
change of work pattern
isolation and segregation
engineering controls
personal protective equipment
15. ROUTES OF ATTACK ON THE HUMAN BODY
route of entry (reach an area of penetration of the body)
process of entry (penetrate the outer cover of the body)
16. ROUTES OF ENTRY inhalation
ingestion
skin pervasion
injection
implantation
aspiration
17. PROCESS OF ENTRY absorption
epidermis
lungs
gastro-intestinal tract
direct entry into the body
18. TOXICOLOGY- the study of poisonous materials and their effects on living organisms toxic substances
systemic
travel through the system
local
act only at the point of contact
cumulative
not readily excreted from the body
accumulated over a period of time toxicity
LD50 to quantify the effects of a toxic agent
Acute Toxicity
harmful effect occurs quickly (seconds, minutes, hours)
Chronic Toxicity
harmful effect takes a long time to appear (months, years)
19. LOCAL AND SYSTEMIC EFFECTS local effects (confined to specific area where contact occurs)
skin
eye
respiratory tract
systemic effects (occur at organs distant from contact site)
liver
nervous system
bone
blood-forming organs
20. DEFENCE MECHANISMS OF THE BODY respiratory defence
physical filtration
phagocytosis
lachrymation
immune response
inflammatory response
fibrotic response
21. CHIP 2 Chemicals (Hazard Information and Packaging for Supply) Regulations 1994
category of danger
indication of danger
symbol
22. HEALTH EFFECTS CLASSIFICATION OF HAZARDOUS SUBSTANCES
very toxic
toxic
harmful
corrosive
irritant
sensitising
carcinogenic
mutagenic
toxic for reproduction
23. APPROVED SUPPLY LIST general nature of the risk (risk phrase) “causes severe burns”
precautions to be taken (safety phrase) “keep out of reach of children”
24. LABELLING supplier information
name of substances or constituents
indication of danger
symbol
risk phrase
safety phrase
25. SAFETY DATA SHEETS composition
hazards
first aid
fire fighting
accidental release
handling/storage
exposure controls
personal protection
physical properties
chemical properties
stability/reactivity
toxicology
ecological information
disposal
26. CATEGORIES OF CHEMICAL AGENT toxic, including carcinogenic
corrosive and irritant
dermatitic and sensitising
27. FORMS OF CHEMICAL AGENT solids
liquids
dusts
fibres
mists
gases
fumes
vapours
28. TYPES OF TOXIC EFFECT respiratory irritants
chemical asphyxiants
haemolytic poisons
narcotics
nervous system poisons
metallic poisons
metallic and polymer fume fever carcinogens
halogenated compounds
nitro-compounds
aromatic amines
polycyclic aromatic hydrocarbons
natural carcinogens
inorganic carcinogens
benzene
29. TOXIC AGENTS physical form(s)
mode of entry to body
target organs
symptoms of exposure
acute
chronic
occupations at risk
30. COMMONLY OCCURRING TOXIC SUBSTANCES lead
mercury
benzene
phenol trichloroethylene
silaceous dust
asbestos
carbon monoxide
31. CORROSIVE AGENTS destroy living tissue
acids and alkalis
injury through
contact with skin and eyes
inhalation
ingestion
32. DERMATITIC AGENTS primary cutaneous irritants
contact dermatitis
at site of contact
recovery on removal of agent
cutaneous sensitisers
sensitisation dermatitis
initial sensitisation
trace contact enough to cause reoccurrence
33. SENSITISERS respiratory system
occupational asthma
inhalation of antigen causes bronchial constriction
sensitisation dermatitis
isocyanates
trace contact enough to cause reoccurrence
34. OCCUPATIONAL EXPOSURE LIMITS (I) designed to control the absorption of airborne contaminants into the body
measured in:
ppm (parts of vapour/gas per million parts of air)
mg/m3 (milligrams of substance per cubic metre of air)
expressed as the concentration of an airborne substance averaged over a reference period
15 minutes short term limit
8 hours long term limit
35. OCCUPATIONAL EXPOSURE LIMITS (II) Maximum Exposure Limit (MEL)
maximum permissible concentration
has legal status
must not be exceeded
reduce exposure to as far below the MEL as possible Occupational Exposure Standard (OES)
concentration at which no evidence of harm
represents good practice
if exceeded, take steps to reduce down to OES
OES represents adequate control
36. OCCUPATIONAL EXPOSURE LIMITS (III) long term limits
time-weighted average concentration
conc. x exposure time averaged over 8 hours
designed to control chronic effects
short term limits
time-weighted average concentration
conc. x exposure time averaged over 15 mins
designed to control acute effects
37. SAMPLING OF AIRBORNE CONTAMINANTS (I) Purpose
qualitative analysis
indicate presence of and identity of contaminants
quantitative analysis
measure concentration and assess compliance with standards
38. SAMPLING OF AIRBORNE CONTAMINANTS (II) Types
“spot” or “grab” sample (stain tube)
taken at a single point at a particular time in the general working atmosphere eg ozone monitoring
time averaged sample (dust sampling)
taken over a period of time, analysed, and averaged over that period (operators breathing zone)
continuous monitoring (direct reading)
continually measured and giving a continuous record of airborne contamination (can be used in conjunction with alarm systems eg toxic chemicals)
39. CONTROL PHILOSOPHY
40. VENTILATION dilution ventilation
dilutes contaminant to an acceptable level
comprises fans set in walls or roof
cheap and simple
limited application as a control strategy
local exhaust ventilation
captures contaminant close to point of generation
comprises hood, ductwork, filter, fan,outlet
good control of hazardous contaminants
41. DILUTION VENTILATION (I) changes the whole workplace air over a given time period ie air changes per hour
limit to circumstances where:
exposure limit is high
low evaporation rate for liquids
slow evolution for gases
operators not close to the point of generation
substance is quickly carried away from the operator
42. DILUTION VENTILATION (II) rate of contaminant generation governs air changes per hour required
density of contaminant governs position of fans:
density >1 (ie solvents) - low level fan in wall
density <1 (ie hot gases) - high level fan in roof
problems include:
“dead areas” where poor airflow allows contamination to build up
heat losses due to high rate of air change
43. LOCAL EXHAUST VENTILATION (I) Hood or exhaust inlet
receptor hood
contaminant directed into a large hood by fan assisted draught
captor hood
contaminant captured by air flow close to point of generation
low pressure large volume flow
high pressure low volume flow (high velocity)
44. LOCAL EXHAUST VENTILATION (II) ducting
straight with gentle bends and angled joints
sufficient air flow to prevent deposition of solids
access ports for cleaning and flow monitoring
filter or purifying system
cyclones, washers, electrostatic, bag filters
45. LOCAL EXHAUST VENTILATION (III) Fans
axial flow fan
airflow is parallel to the shaft of the impeller
compact and fits neatly into ductwork
centrifugal fan
air enters the impeller then is discharged at right angles
exhaust outlet
careful location to avoid:
cyclic pollution
effects of weather of air disturbance
46. BIOLOGICAL HAZARDS zoonoses
animal infections transmitted to persons in the course of their work
bacilli
infections such as Legionnaire’s or Weil’s disease
fungi
extrinsic allergic alveolitis
blood-borne infections
hepatitis B and AIDS
47. ZOONOSES Brucellosis (bacterium)
cattle, pigs
Q Fever (bacterium)
cows, sheep
Orf (virus)
sheep
Psitticosis (bacterium)
poultry, birds
Anthrax (bacterium)
farm animals
Glanders
horses, donkeys, mules
48. CONTROL STRATEGIES FOR ZOONOSES routes of entry
skin penetration
cuts, sores, abrasions
injection by bites
contact with conjunctiva of eye
inhalation
contaminated dust
ingestion
contamination via hands
control strategies
eliminate
immunisation
improve animal stock
enclosure
infected aerosols
ventilation
infected dusts from wool, skin, hides
hygiene
disinfection
personal protective equipment
49. LEGIONNAIRES’ DISEASE caused by inhalation of airborne droplets containing the legionella bacteria
pneumonia-type symptoms
manage the risk by:
identifying and assessing sources of exposure
contaminated sprays and aerosols
avoid conditions where legionella can proliferate (water temperature,stagnation, treatment)
persons at risk
susceptible persons ie hospital patients
50. WEIL’S DISEASE caused by infection from rats
type of bacteria (Leptospira icterohaemorrhagiae)
enters body through cuts/abrasions of skin
jaundice-type symptoms
manage the risk by:
identifying and assessing sources of exposure
destruction of rat infestation
immunisation, first aid, information, protective clothing
persons at risk
canal workers, sewer workers, abattoir workers
51. BLOOD-BORNE INFECTIONS hepatitis B (virus)
severe form of jaundice
infection through contact with blood or bodily fluids
persons at risk include health workers and emergency services
protect through preventing puncture wounds, disinfection and disposable gloves AIDS (virus)
debility of immune system
infection through contact with blood or bodily fluids
persons at risk include health/social workers and emergency services
protect through preventing puncture wounds, disinfection and disposable gloves
52. SUBSTANCES HAZARDOUS TO HEALTH classified as dangerous to health under the current CHIP Regulations
assigned a MEL or OES
biological agent
dust in a substantial concentration
any other substance which creates a comparable health hazard
53. REQUIREMENTS OF COSHH assess the risks to health arising from exposure
prevent or adequately control exposure
ensure that control measures are used and properly maintained
monitor exposure and carry out appropriate health surveillance
ensure that employees are properly informed, trained and supervised
54. COSHH ASSESSMENT (I) which hazardous substances are present?
brought into the workplace
dusts, fumes, leakages
finished products or wastes
who might be exposed?
employees
contractors
public
55. COSHH ASSESSMENT (II) do they represent a significant risk?
hazardous properties (toxic, corrosive, irritant)
quantity used and frequency of use
possible routes of exposure (inhalation, contact)
possibility of exposure exceeding OEL
possibility of leakage, spillage or release
cleaning and maintenance operations
56. PREVENTING EXPOSURE change the process or activity
the hazardous substance is not required or generated
replace the hazardous substance with a safer alternative
use the hazardous substance in a safer form
57. CONTROLLING EXPOSURE totally enclose the process
partially enclose the process and use local exhaust ventilation
use general ventilation
use systems of work and handling procedures that minimise spills and leaks
reduce the duration of exposure
58. MONITORING EXPOSURE HEALTH SURVEILLANCE monitoring exposure
where serious risks if controls fail
to confirm exposure limits are not exceeded
to confirm that controls are working properly
keep records health surveillance
where exposure is linked to a disease which could occur and can be detected
where employees are working in a process listed in schedule 5 and exposure could be significant
59. RECORDING AND REVIEWING THE ASSESMENT record enough information:
to show how decisions on risks and precautions were made
to clearly show the responsibilities for implementing the precautions review the assessment:
at no less than 5-yearly intervals
whenever it is thought that the assessment might not be valid
where there has been a significant change in the work
60. INFORMATION, INSTRUCTION AND TRAINING inform, instruct and train employees about:
the nature of the substances and the risks arising from exposure
the precautions that should be taken
give information and instruction on:
the purpose and use of control measures
use of personal protective equipment
results of any monitoring or health surveillance
emergency procedures
61. DISPOSAL OF HAZARDOUS SUBSTANCES (I) Safe Storage
segregate
control storage to prevent risks to employees and others
keep hazardous and non-hazardous waste separate
ensure correct labelling
keep quantities to a minimum
separate incompatible hazardous wastes
62. DISPOSAL OF HAZARDOUS SUBSTANCES (II) Transport
use correct type of vehicle
inspect load prior to transport to check:
description of material
containment
labelling
documentation
transfer waste only to an authorised person
transfer must be accompanied by written documentation:
identification
quantity
time and place of transfer
details of current and intended holder
special waste requires use of a consignment note