nebosh national general certificate

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