COSHH Course: Control of Substances Training

COSHH stands for Control of Substances Hazardous to Health. The Control of Substances Hazardous to Health Regulations 2002 require employers to prevent their employees being exposed to substances hazardous to health or, where that is not reasonably practicable, to control the exposure adequately. The Regulations are made up of 21 regulations and Schedules 1 to 9 plus 2A. Alongside them sit HSE’s Approved Code of Practice and guidance, L5, and EH40, which holds the workplace exposure limits. COSHH applies in England, Scotland and Wales, and HSE says it applies in private homes as well as on commercial sites.

For electricians, COSHH is part of the daily job. Chasing a wall or drilling concrete makes respirable crystalline silica dust, cutting MDF makes wood dust, soldering with rosin flux gives off a fume that HSE calls a common cause of occupational asthma, and some foams and glues contain isocyanates. HSE names health effects including silicosis, lung cancer, occupational asthma and dermatitis, and wet cement can burn the skin.

COSHH does not cover everything. Asbestos and lead, including lead solder, have their own regulations, and a substance that is hazardous only because it is flammable, explosive or radioactive, or only because of its temperature or pressure, is outside COSHH. The BS 7671 wiring regulations address electrical safety, while COSHH covers the substances you breathe in or get on your skin. Employers must give suitable and sufficient information, instruction and training to anyone whose work is liable to expose them to a substance hazardous to health.

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Electricians work with a surprising number of hazardous substances during typical installation and maintenance work. Understanding what you are handling and the risks involved is the first step towards protecting yourself.

Solvents and adhesives such as solvent cements, glues, cleaners and paints contain volatile organic compounds. HSE says solvents can harm you if you breathe them in, get them on your skin or in your eyes, or swallow them, and high airborne concentrations of some solvents can cause unconsciousness and death. Use low or no-solvent products where you can, keep lids on, make sure there is ventilation, wear suitable gloves and never use solvents to clean your skin. The label and safety data sheet tell you what is in the product.

Rosin-based solder flux fume is, in HSE’s words, a common cause of occupational asthma. EH40 sets its workplace exposure limit at 0.05 mg/m³ over 8 hours and 0.15 mg/m³ over 15 minutes, marked Sen, and because it can cause asthma, exposure must be reduced as low as is reasonably practicable. HSE suggests crimping or rosin-free fluxes where they will do the job. Lead in solder comes under the Control of Lead at Work Regulations 2002, not COSHH. Soldering repairs during inspection and testing work need the same assessment as soldering on a new installation.

Drilling dust from concrete, brick, and blockwork contains respirable crystalline silica, which HSE says is too fine to see in normal lighting. HSE names silicosis, COPD, lung cancer and asthma. The EH40 limit is 0.1 mg/m³ over 8 hours, marked Carc where it is generated by a work process. For chasing, HSE’s controls are on-tool extraction (H or M class) and RPE with an assigned protection factor of 20; for drilling it depends on how much you do, with RPE of APF 20 as well when drilling is a main activity. Never dry sweep the dust afterwards.

Expanding foams, adhesives, cement and batteries all present their own hazards. Some polyurethane foams and glues contain isocyanates, which HSE says cause irritation, dermatitis and occupational asthma; the EH40 limit is 0.02 mg/m³ over 8 hours and 0.07 mg/m³ over 15 minutes, as NCO, marked Sen. Wet cement is highly alkaline and can burn the skin, and battery electrolytes contain sulphuric acid or potassium hydroxide, which HSE describes as very corrosive. Asbestos is not a COSHH substance, but in a building built before 2000 it is the first question to ask before drilling. The asbestos awareness course covers another critical substance hazard for electricians working in pre-2000 buildings.

A COSHH assessment is the starting point for any work with hazardous substances. Regulation 6 says an employer must not carry out work liable to expose employees to a substance hazardous to health unless a suitable and sufficient assessment has been made and the steps it identifies have been put in place. There is no set form. Whoever does it must be competent, and HSE says no particular qualification is needed.

Step 1: identify the substances. List what you will bring to the job, such as solvent cements, glues, foams and flux, and what the work itself will make, such as dust, fume and vapour. Get the safety data sheet for each classified product. Dust and fume made by the work have no safety data sheet but still need assessing, and HSE’s COSHH essentials sheets can help.

Step 2: understand the hazards and the routes in. The label and safety data sheet give the classification, hazard statements and precautionary statements, but a safety data sheet is not a risk assessment. Think about every route into the body: breathing it in, skin contact, absorption through the skin, swallowing and puncture.

Step 3: decide who could be exposed and how much. Consider the level, type and duration of exposure, maintenance work where exposure could be higher than normal, and anyone else affected, such as other trades, the householder or members of the public. Check whether EH40 sets a workplace exposure limit for the substance.

Step 4: prevent, then control. Prevent exposure where reasonably practicable, with substitution preferred; HSE’s examples include over-covering cables instead of chasing. Where you cannot prevent it, control it in the regulation 7 order of priority, with personal protective equipment only where adequate control cannot be achieved by other means, and then in addition to the other measures.

Step 5: record, put it in place and review. With 5 or more employees, record the significant findings and the steps taken. Put the steps in place before the work starts, make sure the people doing the work know them, and review the assessment regularly and straight away if it may no longer be valid, the work changes significantly or monitoring results show it is needed. Recording your CPD activities including COSHH study keeps a note of what you have covered.

Regulation 7 sets the order. Exposure must first be prevented, with substitution preferred. Where prevention is not reasonably practicable, exposure must be adequately controlled in this order of priority: suitable work processes, systems and engineering controls; control at source, including adequate ventilation and organisational measures; and only then, where adequate control cannot be achieved by other means, personal protective equipment in addition to the other measures. HSE says PPE is the last line of protection: it protects only the wearer and can fail without warning.

Prevention means designing the substance or the dust out of the job. HSE’s examples for electrical work include limiting chasing at the design and layout stage, over-covering cables, keeping the number of holes down and using direct fastening or screws.

Substitution means swapping to a substance or process that removes or reduces the risk. HSE suggests crimping or rosin-free fluxes in place of rosin-based flux, and low or no-solvent products in place of solvent-based ones. A substitute must be assessed in its own right: one that is less toxic but more flammable might increase the overall risk.

Engineering controls include local exhaust ventilation (LEV) to capture dust and fume at source, and on-tool extraction counts as LEV. Check it before use, and have it thoroughly examined and tested by a competent person at least once every 14 months, keeping the records for at least 5 years. HSE recommends planning the test once a year so it never runs past the 14 months.

RPE and PPE selection must match the hazard and the wearer. HSE gives assigned protection factors of 4 for FFP1, 10 for FFP2 and 20 for FFP3 or a half mask with a P3 filter, and says construction dust needs RPE with an APF of 20, so a basic dust mask is not enough for silica. The ACOP says tight-fitting RPE should be face-fit tested and worn clean-shaven where it seals; with a beard, choose loose-fitting powered RPE. HSE notes that P3 filters do not protect against isocyanate vapour. Choose gloves from the safety data sheet, remember that barrier cream is not a glove, and expect the employer to provide PPE free of charge. The Elec-Mate course covers RPE, gloves and PPE for common electrical jobs.

Whether you are working on a domestic installation or a large commercial project, the same COSHH principles apply. HSE says COSHH covers work in private homes, so the duty to assess and control is the same.

Regulation 13 says the employer must plan for accidents, incidents and emergencies involving hazardous substances: procedures including first aid, safety drills tested at regular intervals, information about the arrangements and a way of raising the alarm, unless the risk is only slight. Knowing the plan before you open the tin stops a small spill becoming an injury.

Skin contact: Follow the first-aid measures in section 4 of the safety data sheet. For solvents and isocyanate products, HSE says wash the product off the skin as soon as possible and never use solvents to clean skin. Wet cement is highly alkaline and can burn, so wash it off promptly.

Eye contact: Follow the first-aid section of the safety data sheet and get medical help where it is needed. HSE says use emergency eyewash to get cement out of the eyes, and warns that battery electrolyte can permanently damage the eyes, so wear goggles or a visor when handling it.

Fume and vapour: HSE warns that high airborne concentrations of some solvents can cause unconsciousness and death, and that carbon monoxide from petrol tools can kill, so use electric tools where you can and never run petrol equipment indoors unless the ventilation has been fully assessed. Smoke and fumes from fire-related incidents are covered in the fire safety course.

Spillage: Follow section 6 of the safety data sheet, accidental release measures. Keep people back: only the people needed to deal with it should be in the area, wearing the right PPE. Some occupational diseases and dangerous occurrences must be reported under RIDDOR, and the course covers which ones.

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Interactive emergency procedure scenarios

The Elec-Mate COSHH course includes scenarios where you plan for spills and splashes, from battery electrolyte in a plant room to wet cement around a back box.

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