Occupational health and safety are critical concerns in welding workshops across Kenya, where handling metals and operating welding equipment pose various risks to workers. Ensuring adherence to engineering material standards and workplace safety legislation protects welders from accidents and long-term health hazards. This chapter evaluates the properties of engineering materials with a focus on occupational safety, hazard identification, waste management, and the establishment of safe workshop procedures. Understanding and implementing these safety measures is essential for welding professionals to maintain a secure and efficient work environment.

1.1 Occupational health and safety standards

A metallurgy and welding workshop is a place where several dangers meet: heat, sparks, ultraviolet light, electricity, compressed gas, heavy metal, noise and fumes. Occupational health and safety is the set of laws, standards and habits that keep the people who work there from being injured or made ill by their work. The rules protect the worker, the people nearby, the equipment and the environment, and a workshop that follows them has fewer accidents, less lost time and lower repair costs.

Working with engineering materials adds its own dangers. Cutting, grinding, heating, casting and testing metals releases dust and fumes, throws off hot particles and puts workers close to machines that can crush or cut. This topic covers the legislation and standards, how hazards are found, how waste is handled, the safety rules and protective equipment of the workshop, the procedures staff follow and the ways of preventing and controlling hazards.

1.1.1 Workplace legislation and standards

Workplace legislation is the body of law that sets out what employers and workers must do to keep a workplace safe. In Kenya the main law is the Occupational Safety and Health Act, 2007. It places duties on the occupier of a workplace to keep it safe, to provide information, training and protective equipment, and to look after the health and welfare of workers. It places duties on workers too: they must follow the safety rules, use the equipment they are given and report dangers. The Directorate of Occupational Safety and Health Services (DOSHS) enforces the Act by inspecting workplaces and advising occupiers.

Other laws and standards apply to the same workshop:

• Work Injury Benefits Act, 2007: provides for compensation to workers who are injured or become ill because of their work.
• Environmental Management and Co-ordination Act, 1999: protects the environment from pollution, and the National Environment Management Authority (NEMA) enforces it. It covers the disposal of waste, smoke and fumes from workshops.
• Standards for materials and equipment: the Kenya Bureau of Standards (KEBS) publishes standards that products sold in Kenya must meet. International standards on materials, welding and testing are also used in workshops, and the quality of metals and consumables is checked against the standard named in the order.

A standard is an agreed specification. A materials standard names the composition and properties a metal must have, so the buyer knows what has been supplied. A safety standard names the level of protection a product such as a helmet or a boot must give. Both help a workshop to buy and use the right items.

1.1.2 Workplace hazard identification

A hazard is anything that can cause harm, and a risk is the chance that the harm happens, together with how serious it would be. Finding the hazards is the first step in controlling them, because a hazard that is not known cannot be controlled.

Methods of finding hazards:

• Workplace inspection: walking through the workshop with a checklist and looking at floors, machines, cables, cylinders, lighting, ventilation and storage.
• Job safety analysis: breaking a job such as grinding a test piece into steps and asking what could go wrong at each step.
• Reports from workers: workers who do the job every day know its dangers, and a simple way of reporting near misses and faults brings them to light.
• Accident and incident records: past accidents show where the workshop has been hurt before.
• Manufacturers' information: data sheets and manuals state the dangers of materials and machines.

After the hazards are listed, each one is rated for risk. A simple method scores likelihood from 1 (unlikely) to 5 (almost certain) and severity from 1 (minor) to 5 (fatal), and multiplies the two. Example: grinding without a face shield may be likely (4) and could cause a serious eye injury (4), so the risk score is 4 × 4 = 16, which is high and needs action at once. Storing a tidy rack of offcuts may score 2 × 2 = 4, which is low. The scores decide which hazards are dealt with first.

1.1.3 Workshop waste management

A metal workshop produces waste every day, and handling it properly keeps the floor clear and avoids pollution. Waste management follows the order of reduce, reuse, recycle and then safe disposal.

Types of waste:

• Metal offcuts, turnings and scrap: these are valuable, and they are collected by metal type and sold or returned for recycling.
• Slag, grinding dust and used abrasive discs: these are collected in a covered container and disposed of with solid waste.
• Used oil, coolants, solvents and paint: these are hazardous waste. They are kept in labelled, sealed containers and passed to a licensed waste handler.
• Rags and cloths soaked in oil or solvent: these can catch fire by themselves, so they are kept in a closed metal bin.
• Empty gas cylinders and spent batteries: cylinders go back to the supplier, and batteries go to a collection point.
• Fumes and dust: these are removed by extraction and ventilation, and are not left to drift into the street.

Segregation means keeping each type of waste in its own marked container so that the hazardous waste is not mixed with the general waste. Hazardous waste is not poured into drains or burned, because it pollutes soil and water and harms the people nearby. Waste carriers and disposal sites should hold the licence that the environmental authority requires.

1.1.4 Workshop safety

Workshop safety is the daily practice of working so that nobody gets hurt. It rests on clear rules, which everyone in the workshop must know and follow, and on protective equipment worn for the tasks that need it. Good housekeeping is part of it: floors are kept clear of offcuts, cables and spills, and tools are put back after use.

1.1.4.1 Regulations

Workshop regulations are the written rules of the workshop, which follow the law and the manufacturers' instructions. They are displayed on a notice board and explained to every new person on the first day. Common rules are listed below.

• Authorisation: only trained and authorised persons may use a machine or a welding set.
• Protective equipment: the correct equipment is worn for each task before the work begins.
• Machine guards: guards are never removed, and a damaged machine is tagged and taken out of use.
• Fire safety: flammable materials are kept away from welding and cutting, and fire extinguishers are kept clear and in date.
• Compressed gas: cylinders are kept upright and secured, with the valve caps on when not in use.
• Conduct: no running, no horseplay and no eating or drinking in the work area.

Safety signs are used to give the rules at the place where they apply. A red sign prohibits an action or marks fire equipment. A yellow sign warns of a hazard. A blue sign gives an order, such as to wear eye protection. A green sign shows safe conditions, such as an exit or the first aid point.

1.1.4.2 Personal Protective Equipment

Personal protective equipment (PPE) is the equipment worn by a person to reduce the risk of injury when a hazard cannot be removed by other means. It is the last line of defence, and it protects only the person who wears it. It must be the right type for the hazard, fit well, be kept in good condition and be replaced when it is damaged.

1.1.5 Workplace procedures

A procedure is a set of steps that people follow so that a task is done safely and in the same way each time. Workplace procedures describe who does what, how it is recorded, how people are told and what to do when something goes wrong.

1.1.5.1 Roles and responsibilities

Everyone in the workshop has a part in safety.

• Employer or workshop owner: provides a safe workplace, equipment, training and protective equipment, and ensures the law is followed.
• Supervisor or instructor: explains the rules, checks that they are followed, inspects the work area and stops unsafe work.
• Safety officer or safety committee: carries out inspections, investigates accidents and advises the management on improvements.
• Worker or trainee: follows the rules, uses the protective equipment, looks after the tools and equipment, and reports dangers, accidents and near misses.

1.1.5.2 Documentation

Documentation is the written record of safety. It proves that the work was done as it should be, and it supplies information for improvements. A workshop keeps the records listed below.

• Risk assessments: the hazards found, their risk and the controls chosen.
• Training and induction records: who was trained, on what and when.
• Inspection and maintenance logs: the checks of machines, extinguishers, cylinders and lifting equipment.
• Work permits: written permission for work with special risk, such as hot work near flammable materials.
• Accident and incident register: every injury or near miss, its cause and the action taken. Serious accidents are reported to DOSHS as the law requires.

1.1.5.3 Communication

Safety communication makes sure that everyone knows the rules and the dangers at the time they need to know them.

• Induction: a talk on the rules and hazards given to everyone who joins the workshop.
• Toolbox talks: short meetings before work starts on one safety topic of the day.
• Safety signs and notices: signs on the wall at the place of the hazard.
• Verbal and written instructions: clear instructions from the supervisor, and written procedures for a complex task.
• Reporting channels: a clear route for passing information about a danger up to the supervisor or the safety officer.

1.1.5.4 Emergency procedures

An emergency procedure tells every person what to do in the first minutes of a fire, an injury or a gas leak. It is displayed, practised in drills and understood by all.

1. Raise the alarm by shouting and by operating the alarm, so that everyone nearby is warned.
2. Make the area safe if it can be done without risk: switch off the machine or the power supply, and close the gas valve.
3. Fight a small fire only if the way out is clear behind you and you know how to use the extinguisher. Otherwise leave.
4. Evacuate by the nearest safe exit to the assembly point, and count the people present.
5. Give first aid to anyone hurt: cool a burn with clean running water, cover it with a clean dressing, and do not touch a person who is in contact with live electricity until the power is switched off.
6. Call the emergency services on 999 or 112, and give the location and the nature of the emergency.
7. Report the event, and record it in the accident register afterwards.

1.1.6 Types of workplace hazards

Workplace hazards are grouped by the way they cause harm. Putting them into groups helps in finding them and in choosing controls.

1.1.6.1 Physical

Physical hazards are caused by energy in the workplace. In a metal workshop they include:

• Arc radiation: ultraviolet and infrared light from the arc burns the eyes (arc eye) and the skin.
• Heat and burns: hot metal, sparks and spatter, and hot slag.
• Electric shock: from damaged cables, wet floors and faulty equipment.
• Noise: grinding, hammering and machine noise that can cause lasting hearing loss.
• Moving machines and flying particles: the risk of cuts, crushing and eye injuries.
• Manual handling: lifting heavy metal causes back and muscle injuries.

1.1.6.2 Chemical

Chemical hazards come from substances that can harm the body by contact, breathing or swallowing.

• Welding fumes and gases: fumes from metals and coatings, and gases such as ozone and carbon monoxide, which cause breathing problems and illness. Fumes from galvanised steel are especially harmful.
• Solvents, degreasers and paints: can burn the skin, harm the lungs and catch fire.
• Acids and cleaning chemicals: used in cleaning and etching of metals, and cause burns.
• Fuel gases and compressed gases: acetylene, which burns and can explode, and oxygen, which makes fires burn fiercer, and others that can leak.

1.1.6.3 Biological

Biological hazards are caused by living organisms or the things they produce.

• Infection of cuts and burns: cuts from rusty or dirty metal can become infected, and a worker should be protected against tetanus.
• Contaminated water and food: poor hygiene in the workshop can cause stomach infections.
• Mould and pests in damp storage and washing areas: these can cause breathing problems and spread disease.
• Shared protective equipment: respirators, gloves and helmets that are shared can pass on infections, so personal items are not shared or are cleaned between users.

1.1.6.4 Environmental

Environmental hazards are conditions of the work setting that can harm the worker, and also the ways in which the workshop harms its surroundings.

• Poor ventilation: fumes and dust build up in a closed workshop.
• Heat and humidity: working in a hot roofed workshop can cause heat exhaustion.
• Poor lighting: causes accidents and eye strain.
• Wet floors, rain and flooding: increase the risk of slips and electric shock.
• Pollution from the workshop: smoke, oils and waste released to the air, soil and water harm the neighbours and the environment.

1.1.7 Prevention and control

Hazards are controlled by working down a hierarchy, starting with the most effective method.

1. Elimination: remove the hazard completely, for example by using a bolted joint in place of a welded one where this is possible.
2. Substitution: replace a hazardous material or process with a safer one, such as a water-based cleaner in place of a solvent.
3. Engineering controls: make the workplace safer by design, with machine guards, local fume extraction, welding screens, earthing of equipment and good ventilation.
4. Administrative controls: change the way people work, by training, written procedures, signs, rotation of tasks and limiting the time of exposure.
5. Personal protective equipment: protect the individual with the correct equipment when the risk remains after the other controls are in place.

The methods higher in the list protect everyone at once and do not depend on the behaviour of the individual, so they are preferred. Example: for fumes from welding galvanised steel, the best control is to remove the coating from the weld area before welding, and then use extraction at the weld, with a respirator as a last measure. Controls are reviewed regularly, and are updated after any accident or near miss.

Chapter Summary

This chapter covered the essential occupational health and safety aspects related to standards engineering, including relevant workplace legislation, hazard identification, waste management, safety regulations, and the use of personal protective equipment. It also detailed workplace procedures, emphasizing roles, documentation, communication, and emergency responses alongside various types of hazards such as physical, chemical, biological, and environmental, with methods for their prevention and control. The properties of metals were examined in depth, focusing on physical characteristics like color and lustre, mechanical properties such as strength, hardness, ductility, and brittleness, as well as thermal properties including melting point and specific heat capacity. Different forms of metal supply were described, ranging from ingots and bars to sheets, strips, and wires, highlighting their typical applications in engineering contexts. The chapter further explained the importance of Mill Test Certificates, their interpretation, and how they are used to verify material quality. Finally, it classified metals into ferrous types, including steel and cast iron, and non-ferrous metals such as aluminium, copper, and titanium, outlining their distinct characteristics and uses.