Element -9 Hazards and controls associated with hazardous substances

Element -9

Hazards and controls associated with hazardous substances

1.      The forms and classification of hazardous substances

2.      Source of information

3.      Hazardous substances control

Hazardous substances

On completion of this element, we should be able to :

1.      Identify the forms of classification and routes of entry of hazardous substances

2.      Outline the sources of information to be considered when undertaking an assessment of the health risk from substances commonly encountered in the workplace.

3.      Identify the controls that should be used to reduce the risk of ill health from exposure of hazardous substances.

This element focuses on risk from the hazards and control associated with exposure to hazardous substances.

These risks may be result of working with chemicals, for examples as part of work process, or may be an indirect effect of a process or devices.

Not all hazardous substances are chemicals however- they come in many forms including gases, dust and even bacteria viruses, and fungi.

Hazardous substances are simply any substances which we could be exposed while working which could cause harm to health.

1.      Chemical hazards

2.      Biological hazards.

Physical from of hazardous substances:

1.      Gases: formless fluids usually produce by chemical process involving combustion (burning) or by the interaction of chemical substances.

2.      Vapor: This is the gaseous form of a material normally encountered in a liquid or solid state at normal room temperature and pressure.

3.      Mists: These are finely isolated liquid dewdrops suspended in air. Mists are mainly created by spraying.

4.      Smoke:  Particles which result in incomplete combustion which can be either solid or liquid state.

5.      Fume: These are solids particles formed by condensation (reduction ) from the gaseous state.

6.      Dusts: These are solid airborne particles often created by operation such as grinding, curshing etc.

7.      Liquids: Substances which are liquid at normal temperature pressure.

8.      Solids: Material which are solid at normal temperature and pressure.

Chemical Hazards

Chemical hazards may include: Acids, metals, non metals, Gases, organic compounds.

Sl.	Chemical	Hazards
1	Acids and alkalis	Dermatitis
2	Metals	Lead and mercury poisoning
3	Non metals	Arsenic and phosphorus poisoning
4	Gases	Carbon monoxide poisoning arsine poisoning
5	Organic compounds	Occupational cancers

Biological hazards

Biological hazards may include: animal borne, Human borne, vegetable borne, and other (water/land)

Sl.	Biological	Hazards
1	Animal borne	Anthrax, brucellosis, rabies
2	Human borne	Viral hepatitis
3	Vegetable borne	Aspergillosis
4	Other (water/land)	Legionella

Control Measures for Biological Hazards:

·         Cleaning/ disinfecting

·         Water treatment programmes

·         Vermin control procedures (pet animal prohibited, controlled)

·         Procedures for handling, containment and disposal

·         Personal hygiene

·         Immunization(to build resistance to specific infections)

·         Health surveillance (strategies and methods to detect and assess systematically the adverse effect of work on the health of workers)

·         Specific training

·         Suitable PPE

Classification of Hazardous substances

1.     Irritant: Non corrosive substance which may cause skin or lung infection through repeated contact. Ex: detergent, bleaches,  glue, and petrol.

2.     Corrosive: corrosive substance may cause burning of living tissue on contact ex: caustic soda and ammonia.

3.     Harmful: Harmful is a term use to label a substance which if inhaled, consumed or penetrated the skin may cause limited risk to health. The risk associated with harmful substance can usually be minimized by MSDS and PPE.

4.     Toxic:  A poisonous substance which attacks one or more of the body organs such as liver, lungs and heart. The effects on the health can be death, acute or chronic damage.

5.     Carcinogenic:  Carcinogen substance affects the body cells to become cancerous example: Asbestos, hardwood dust and some mineral oils.

6.     Mutagenic:  Mutagenic substance may cause genetic defects that can be heritable from generation to generation.

Routes of entry:

1.     Inhalation: The most significant industrial entry rout is inhalation. It has been estimated that at least 90% of industrial poison absorbed through the lungs. Harmful substance can directly attach the lung tissue causing a local effect, or pass through the blood system to be carried round the body and affect large organs such as the liver.

2.     Ingestion: The route normally present the least problem as it is unlikely that any significant quantity of harmful liquid of solid will be swallowed without deliberate intent. However accident will occur if eating , drinking or smoking, in chemical areas is allowed.

3.     Absorption(skin contact): Substance can enter through the skin, cuts or abrasion and conjunctiva of the eye. Solvent such as toluene and trichloroethylene can enter either accidently or if used for washing. The substance may have a local effect such as deffatting of the skin or pass through into the blood system

4.     Injection: A forceful breach of skin, perhaps as a result of injury can carry harmful substance through the skin barrier. Hazardous substances can also enter through cuts.

Dose and Response:

How much of a substance we are exposed to and how long the exposure to the substance lasts.

This produces the response which is how the body to the exposure. The Response can depend on things such as body weight, age, skin type, sex, diet and general health.

The effects of Exposure could be:

·         Acute effect: An immediate or rapidly produced adverse effect, following a single short term exposure to a hazardous substance usually with a rapid or immediate response which is normally reversible. The effects could be:

Headaches, dizziness, nausea, inflammation, eye irritation, unconsciousness and death.

·         Chronic: Adverse health effect resulting from prolonged, repeated exposure to a hazardous substance the response being gradual (often unrecognized for long time may get worse with no further exposure and is often irreversible)

·         Local Effects: Usually confined to the initial point of contact. Possible sites affected include the skin, mucous membranes or the eyes, nose or throat. Skin by acidic substance (acids and alkalis) asbestos damaging lung tissue.

Asbestos: Asbestos is one of hazardous agent, it is a fibrous mineral silicate which occurs in several different forms in nature. The three main types are

Ø  White(chrysotile)

Ø  Brown(amosite)

Ø  Blue(crocidolite)

White asbestos is less likely to causes disease. However asbestos dust is generated and may be inhaled a hazard exists.

There are three major disease caused by exposure to asbestos and there are:

a)      Asbestosis (lung tissure is replaced by fiber tissue)

b)     Mesothelioma(cause tumours)

c)      Lung cancer (growth of malignant cells in lungs)

Asbestos: Asbestos has been used for may purpose such as :

·         Cloths for protective clothing

·         Insulation boards for fire protection in building

·         Insulation boards for equipment

·         Pipework lagging

·         Asbestos cement boards for building and pipes

·         Gaskets, filters, brake linings

·         Plasterwork in old buildings

·         Sprayed on for thermal and acoustic insulation

Workers who may be at risk are: Maintenance and demolition workers who may inhale fiber.

Sources of information on hazardous substances:

·         Manufacturers

·         Governmental bodies

·         Enforcement agencies

·         The ILO codes of practice (Safety in the use of chemicals at work)

·         Trade associations

·         Insurance companies

·         Organization involved in occupational health.

Manufacturer’s safety Data Sheet MSDS:

MSDS should be provided by the supplier of the hazardous substance, MSDS are not at risk assessment because they do not consider how substance is to be used.

The information generally found on MSDS:

·         Identification of substances/ preparations

·         Information of manufacturer / supplier

·         Composition/ information on ingredients

·         Hazard identification

·         Health effects and first aid measures

·         Fire fighting measures

·         Accidental release measures

·         Handling and storage

·         Exposure controls

·         PPE

·         Disposal consideration

·         Physical and chemical properties

·         Stability and reactivity

·         Toxicological information

·         Transport information

·         Regularly information

Hazardous substances Assessment:

·         Identify the Hazards: This can be done by MSDS and for looking hazards the following need to be considered:

1.      How much of the substance is use or produced by the process

2.      What is the activity risk

3.      How long and how often the exposure

4.      Who can be exposed and how

5.      How can the substance enter the body

6.      In what for is the substance

7.      What is the concentration of the substance

8.      Is the substance assigned ad exposure limit

9.      Are they any ill-health reports.

10.  Look at the results of health surveillance

·         Decide who might be harmed and how: Operators, other, pregnant and young worker.

·         Evaluate the Health risk: Likelihood and severity, existing control measures, judgment about need for further control measures.

·         Record the significant findings

·         Review The assessment:

·         Test of controls indicate a problem

·         Results of monitoring

·         Results of health surveillance

·         Complaints from workforce

·         New process or substance introduced

·         Change in exposure limit

·         Employee contracts illness

·         Increase in use of hazardous substance

·         Supervision reports improper use of equipment

·         Enforcement actions

·         Compensation claims

Prevention and control of exposure:

1.     Eliminate the hazard

2.     Reduce the risk by substitution

3.     Isolate the people from the hazard (total enclosure, segregate the people)

4.     Control (Maintenance of controls, change the work pattern, Hygiene, housekeeping)

5.     Suitable personal protective equipment

6.     Discipline maintained

7.     IITS (information, instruction, training, supervision)

Emergency Procedures:

1.       First aid facilities

2.       Relevant safety drills

3.       Suitable warning devices

4.       Suitable training of staff

5.       Availability of ppe

6.       Provision of emergency showers and eye wash facilities

7.       Spillage and leakage procedures

8.       Evacuation procedures

9.       Warning to other people.

Storage Waste:

v  Storage area of sufficient size

v  Storage are suitable located(away from drains etc.,)

v  Storage area clearly labeled

v  Individual container clearly labeled

v  Different types of waste stored separately

v  Different type of waste stored separately

v  Incompatible wastes never stored together

v  Appropriate containers for type of waste

v  Storage of waste kept to a minimum distance

v  Protect wastes from the element if necessary

v  If necessary protect storage area with bunds

v  Do not dispose of hazardous waste in general waste skips

v  Ensure storage area secure

Spillage procedures (leakage)

This procedure outline the requirements for the management of chemical spills in the workplace to minimize effects to health and safety from exposure to chemical spills and reduce the impact on the environment.

v  Isolation of area

v  Evacuation of employees

v  Bunds(precautions) to contain spillage

v  Suitable Ppe

v  Contact with emergency services

v  Safe disposal of spilled material.