Chemical contamination

Chemicals play a major role in everyday life. They are used extensively throughout industrial sectors as well as in private residences. Products from the chemical industry provide the foundations for nearly all manufacturing activities. They are found in the making of a wide variety of products ranging from pesticides to man-made fabric, and even cosmetics.

With the amount and wide variety of hazardous substances used for industrial and domestic activities, the scope of concern has been extended. It has become apparent that not only does their impact on the health of people need to be taken into account but also their environmental impacts have to be controlled as well. Any management system introduced has to ensure all the health, safety and environmental aspects of a hazardous substance are included. This would comprise the full life cycle from production to use to disposal. An important aspect of the disposal phase is what happens when the product breaks down. The product itself may have a limited impact on the environment but its constituents, once broken down, may be very harmful. As people have become more aware of the impacts that such chemicals have on people’s health and the environment, new and more stringent standards have been introduced to ensure their impacts are reduced to a safe level. This legislation covers all aspects of hazardous substances - use, supply, transportation and storage.

Classification of hazardous substances

It is a legal requirement for employers to prevent ill health to employees and others as a result of exposure to hazardous substances. Compliance with the Control of Substances Hazardous to Health Regulations 2002 (COSHH) will ensure this requirement is met. In order to fully understand the actions required it is firstly necessary to ensure that the term ‘hazardous substance’ is understood. The COSHH regulations define a hazardous substance as “any substance, including preparation which is: • A substance or mixture of substances classified as dangerous to health under the Chemicals (Hazard, Information and Packaging for Supply) Regulations 2002 • A substance with a workplace exposure limit as approved by the Health and Safety Commission • Biological agents (bacteria and other micro-organisms), if they are directly connected with the work or if exposure is incidental, such as with farming, sewage treatment or healthcare • Any kind of dust in a concentration in air of more than 10 mg/m3 as a time-weighted average over an eight hour period of inhalable dust or 4 mg/m3 as a time-weighted average over an eight hour period of respiratable dust • Any other substance which has comparable hazards to people’s health, but which - for technical reasons - may not be specifically covered by CHIP e.g. some pesticides, medicines, cosmetics or substances produced in chemical processes Hazardous substances include substances used directly in work activities or substances produced during work activities. This grouping all includes substances occurring in nature, such as grain dusts. Hazardous substances can be found in nearly all working environments, from factories and farms to offices, and have differing effects depending on the nature of the product. Some hazardous substances can cause mild irritations, while some can cause occupational asthmas and cancers. So it is imperative that people are made aware of the hazardous nature of the substances. This is achieved through various methods including: • Product classification and labeling • Hazardous substance warning signs • Material safety data sheets

Chemicals and their impact

Chemicals that can have a negative impact upon the environment, should they be misused or disposed of incorrectly, come under the ‘Dangerous for the Environment’ classification. Any product with this symbol requires particular care to be taken when disposal occurs. This category was introduced under the Chemicals (Hazard Information and Packaging for Supply) Regulations 2002, according to directive 67/548/EWG by the European Chemicals Bureau. The primary objective of classifying substances and preparations as dangerous for the environment is to alert the user to the hazards these substances and preparations present to ecosystems. Although the present criteria refer largely to aquatic ecosystems, it is recognised that certain substances and preparations may simultaneously or alternatively affect other ecosystems whose constituents may range from soil microflora and microfauna to primates.

Risk and safety phrases - aquatic environment

• R50 Very toxic to aquatic organisms • R51 Toxic to aquatic organisms • R52 Harmful to aquatic organisms • R53 May cause long term adverse effects in the aquatic environment Non-aquatic environment • R54 Toxic to flora • R55 Toxic to fauna • R56 Toxic to soil organisms • R57 Toxic to bees • R58 May cause long term adverse effects in the environment • R59 Dangerous for the ozone layer The safety phrases associated with the ‘Dangerous for the Environment’ symbol are as follows: • S35 This material and its container must be disposed of in a safe way • S56 Dispose of this material and its container to hazardous waste collection point • S57 Use appropriate containment to avoid environmental contamination • S59 Refer to manufacturer/supplier for information on recovery/recycling • S60 This material and its container must be disposed of as hazardous waste • S61 Avoid release to the environment. Refer to special instructions/safety data sheet

Final choice of ‘R’ and ‘S’ phrases

Although the final choice of the most appropriate ‘R’ and ‘S’ phrases is primarily governed by the need to give all necessary information, consideration should also be given to the clarity and impact of the label. With clarity in mind, the necessary information should be expressed in a minimum number of phrases.

Use and storage of hazardous substances

The control of substances in the workplace is dealt with under two sets of legislation: The Control of Substances Hazardous to Health Regulations, 2002 (COSHH) and the Dangerous Substances and Explosive Atmospheres Regulations, 2002. COSHH requires that risk assessments are made on the hazardous substances used and/or created within a workplace and how they are likely to affect people. They require adequate controls to be put in place to minimise any likely outcome. These regulations require that plans and procedures be developed to deal with accidents, incidents and emergencies involving the hazardous substances. For the vast majority of commercial chemicals, the presence (or not) of a warning label will indicate whether COSHH is relevant. The Dangerous Substances and Explosive Atmosphere Regulations 2002 (DSEAR) require the avoidance or minimising of the release of a dangerous substance. Where this cannot be achieved, the release of a dangerous substance at the source must be controlled. These regulations also ensure that any release of a dangerous substance which may give rise to risk is suitably collected, safely contained, removed to a safe place, or otherwise rendered safe, as appropriate. These regulations will require measures to be put in place to prevent or minimise accidental release. Such measures include: • A minimum amount of dangerous substances to be present on site • Substances only used by those trained to do so • Storage of products in labeled cabinets or bunded areas

Pollution prevention and control

The purpose of these regulations is to achieve high levels of environmental protection, in particular preventing or - where that is not practicable - reducing emissions into the air, water and land. Emissions that these regulations take into account (if they have fixed emission values) are: 1. For air • Sulphur dioxide and other sulphur compounds • Oxides of nitrogen and other nitrogen compounds • Carbon monoxide • Volatile organic compounds • Metals and their compounds • Dust • Asbestos (suspended particulates, fibres) • Chlorine and its compounds • Fluorine and its compounds • Arsenic and its compounds • Cyanides • Substances and preparations which have been proven to possess carcinogenic or mutagenic properties or properties which may affect reproduction via the air • Polychlorinated dibenzodioxins and polychlorinated dibenzofurans 2. For water • Organohalogen compounds and substances which may form such compounds in the aquatic environment • Organophosphorus compounds • Organotin compounds • Substances and preparations which have been proven to possess carcinogenic or mutagenic properties or properties which may affect reproduction in or via the aquatic environment • Persistent hydrocarbons and persistent and bioaccumulable organic toxic substances • Cyanides • Metals and their compounds • Arsenic and its compounds • Biocides and plant health products • Materials in suspension • Substances which contribute to eutrophication (in particular, nitrates and phosphates) • Substances which have an unfavourable influence on the oxygen balance (and can be measured using parameters such as BOD or COD) In order to control these emissions, the regulations stipulate the requirement for the person in control of the site to acquire a permit, where necessary, for installations and mobile plant undertaking activities in the following industries and activities.

Control of Major Accident Hazards (amendment) Regulations 2005

Another set of regulations which applies to the requirements of notification are the Control of Major Accident Hazards (amendment) Regulations 2005. These regulations stipulate that any establishment having a substance at or above the qualifying quantity (as specified in Schedule 1 attached to these regulations) is subject to the regulations. Under these regulations a major accident is described as “an occurrence (including a major emission, fire or explosion) resulting from uncontrolled developments in the course of the operation of any establishment and leading to serious danger to human health or to the environment, immediate or delayed, inside or outside the establishment, and involving one or more dangerous substances.” The regulations have established two thresholds - lower-tier and top-tier, each having differing notification requirements. When the quantity of substances reaches or exceeds the designated maximum, lower-tier operators must notify the competent authority (local HSE office). Operators in this tier must also take all measures necessary to prevent major accidents and report any that do occur as well as producing a Major Accident Prevention Policy (MAPP) in consultation with employees or employee representatives. The requirements for MAPPs are noted in Schedule 2. Top-tier operators must submit a written safety report where the level of substances equals or exceeds the maximum quantity. The report is required to demonstrate that all necessary measures to prevent and limit the consequences of accidents have been taken. If operators are planning to build a new top-tier establishment, they must submit information three to six months before construction and must wait for the competent authorities’ response before commencing. Emergency planning requirements are also necessary for this tier, guidance on which can be found in HSG191. Some of the establishments regulated under the COMAH regulations are also regulated by the agencies under the Pollution Prevention and Control Act (PPC) 1999. Both sets of legislation require establishments to have good risk control management systems in place. PPC includes a specific duty to prevent and mitigate accidents to the environment which is complementary to the main COMAH duty.

Major accidents to the environment (MATTE)

Major accidents to the environment are determined by a combination of the time it takes for a recovery, the extent and severity of the damage. These types of accidents can be caused by a variety of factors such as: • Release of dangerous substances into water sources • Spills leading to fires or explosions • Contamination of flora and fauna from accidental releases • Release of gases Such accidents can have devastating effects on the environment - soil and water contamination affects all levels of species in the food chain as well as plant life and habitats.


Pesticides are defined by the Food and Environment Protection Act 1985 (FEPA) as “any substance, preparation or organism prepared or used, among other uses, to protect plants, wood or other plant products from harmful organisms, to regulate the growth of plants, to give protection against harmful creatures or to render such creatures harmless.” Pesticides are generally thought of as being chemical in nature but in fact they can also be natural substances - often used in organic farming to control pests or altered versions of natural chemicals. 80% of all pesticide use in England and Wales comes from the agricultural and horticultural sectors. In this industry, they are used to: • Protect growing crops from pests, weeds and fungal diseases • Prevent contamination of stored foods by mice, rats or flies • Prevent crops been infected by fungi in order to protect human wellbeing Their use in these areas had increased over the last half decade due to rising demands and expectations from consumers, supermarkets and the government, all requiring plentiful, unblemished food all year round. This increased usage was noted by various monitoring organisations and now pesticides are designed so that as little as possible is needed and then only as a last resort. This had led to farmers using about two-thirds of the chemicals they did in 1983. Pesticides also have uses outside the agricultural umbrella and cover a wide range of products including insecticides, fungicides, rodenticides, herbicides or molluscicides. They: • Protect crops by eliminating insects and weeds • Stop weed growth on areas such as pavements and railway lines • Preserve timber • Prevent pests attacking clothing and carpeting materials • Protect animals by controlling certain diseases (e.g. by use of sheep dips) • Protect hulls of boats from marine organisms Due to the increased use and potentially environmentally damaging aspects of certain pesticides, many of the more toxic and environmentally damaging products have been banned over the years and less harmful alternatives introduced. It should also be noted that it is not necessarily the amount of the substance used but the toxicity of the substance that determines the level of impact those substances will have on the environment. As pesticides are used to kill unwanted pests, weeds and moulds, they can also harm people, wildlife and the environment. This is why there are strict controls in place over their sale and use.

Environmental impact

Generally, unless there are visible outcomes from a pollution event such as dead fish or oil slicks, they will go unreported and therefore not investigated. The seriousness of a pollution incident is determined by its environmental impact. The effects of pollution incidents to air, land and water are categorised from 1 (the most serious incidents) to 4 (no environmental impact). Examples of how pesticides can enter the environment: • Splashed or spilled into water bodies when sprayers are filled, emptied and cleaned, or when equipment is left out in the rain • Ditches are oversprayed, contaminating freshwater via spraydrift • Used or disposed of incorrectly by home owners or amenity users (such as those who look after golf courses, public parks) • Washing down of pesticide application equipment to a surface water drain, accidental spill of crop sprayer contents into a ditch and topsoil runoff following heavy rain Pesticides can cause serious environmental problems due to their varying chemical and physical properties. Pesticides may also form residues on the food plants they are intended to protect, or reside in the soil where those crops are grown. Some chemicals when they enter the environment can linger and cause immediate problems, such as oil spills, while others degrade quickly. The degradable products may seem like the less dangerous of the two groups but this is not always the case. When some chemicals degrade, the products produced by this breakdown may be more harmful, more toxic to plants, wildlife than the original substance. Pesticides are designed to kill specific pests e.g. insects or fungi, but once degraded these chemicals may have the ability to kill other types of species and contaminate an entire food chain. Poisoning of many predatory bird species, such as barn owls has occurred through the introduction of rodenticides. Those species not affected by the poisoning elements of the pesticides have suffered through a decline in available food stocks. Pesticides have the ability to totally devastate the aquatic environment if they are not controlled or if they are carelessly discarded after or during use. Many pesticides are toxic to various species within these environments. Pesticide pollution occurs from many differing sources. Agriculture is the main source of aquatic pollution in many areas but other sources include industry, sewage works, urban runoff, and in coastal areas, boat hull treatment products. Pesticides, if not controlled, enter ground water systems and from there have the ability to contaminate drinking water. To ensure drinking water is safe for human consumption, it needs to be treated by the water companies. This costs millions each year, with those costs transferred to the consumer. Once treated, drinking water is largely free of pesticides. Once a water store is contaminated by pesticides, it can remain polluted for many years and cost vast amounts to clean up, if indeed this can be acheived. It is essential to protect these ground water stores as they account for a third of all our drinking water sources.


Andrew Taylor is currently a Chartered Safety Practitioner working with SHEilds Ltd as a support tutor on the NEBOSH National Diploma Course. He has extensive experience in Health, Safety and Environmental Management, most recently in consultancy and construction environments. +44 (0) 1482 806 805 Published: 10th Dec 2011 in AWE International