Chemical safety includes all safety policies, procedures and practices designed to minimize the risk of exposure to potentially hazardous chemicals. This includes the risks of exposure to persons handling the chemicals, to the surrounding environment, and to the communities and ecosystems within that environment. [1] Manufactured chemicals, either pure or in mixtures, solutions and emulsions, are ubiquitous in modern society, at industrial, occupational and private scale. However, there are chemicals that should not mix or get in contact with others, as they can produce byproducts that may be toxic, carcinogenic, explosive etc., or can be dangerous in themselves. To avoid disasters and mishaps, maintaining safety is paramount. [1]
Chemical safety refers to safety issues surrounding the use, production, transport and handling of chemicals at large or small manufacturing facilities, laboratories, non-chemical sites that use manufactured chemicals for their business, or homes during everyday activities. While there is some overlap, it is different from process safety, which is concerned with more than just hazardous chemicals (extending for example to refined and unrefined hydrocarbons). Process safety is specific to industrial process plants, and focuses primarily on major accidents rather than both immediate and long-term effects (such as chemical carcinogenity).
The hazardous nature of many chemicals may be increased when mixed with other chemicals, heated or handled inappropriately. In a chemically safe environment, users are able to take appropriate actions in case of accidents, [2] although many incidents of exposure to chemical hazards occur outside controlled environments such as manufacturing plants or laboratories.
It is estimated that 1.6 million human deaths occur each year from contact with hazardous chemicals [1] and that in 2016, 45 million disability-adjusted life-years were lost, a significant increase from 2012. [3]
Chemicals in use in industry and research have a range of properties which cause them to be hazardous to life. These include explosiveness, flammability, toxicity, carcinogenicity and teratogenicity. [4] Corrosive substances such as strong alkalis or acids can cause chemical burning. Any one chemical or mixture may exhibit several of these properties.
Toxic materials may be solids in powdered or finely divided form, liquids and gases. Any of these materials may all be absorbed by inhalation, directly through the skin of by contact with mucous membranes in the nose or eyes. Some chemicals may persist in the body for substantial periods and can continue to exhibit toxicity. Examples of such materials include mercury, arsenic, dioxins and many organic solvents which can be stored in fat cells.
Environmental risks may be difficult to evaluate and may take years to become apparent. The risk to the Earth's ozone layer from the release of CFCs required the investigative powers of scientists throughout the world to understand fully. Science is still working out the seriousness of the effects of persistent halogenated organics on the marine food chain, with some of these chemicals becoming concentrated in the fatty deposits of top predators in concentrations that appear to effect their reproductive success.
The management and control of chemical safety is widely developed through primary legislation, and orders derived from such legislation in the western world and in Australasia. The implementation of such legislation follows a variety of patterns, from the European model of detailed directives and orders implemented through country-specific legislation to the US model of wide-ranging federal enactments. The control of this is divided between State legislation and federal government. Examples from these areas are described below.
The Chemicals Agents Directive, a daughter directive of Directive 89/391/EEC, provides the framework for managing chemical safety. [5] The European Chemicals Agency is the responsible agency and specifically implements Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), sets the standards and ensures compliance across the European Union. The European Chemicals Agency sits under REACH and manages the technical and administrative aspects of the implementation of the Directive.
The administrative framework is based on Health and Safety at Work (Hazardous Substances) Regulations 2017 [6] and is implemented and enforced by Worksafe, a government agency. Although this legislation is comprehensive in its coverage it does not extend beyond the workplace and imposes no duties or responsibilities in regard to hazardous materials in domestic or educational establishments.
In the UK legislation to address chemical safety has been incorporated in many pieces of legislation from the early factories acts onwards. The current Health and Safety at Work etc. Act 1974 provided an all encompassing piece of legislation which covered chemical safety amongst a wide range of other measures designed to improve the safety in the workplace in the UK. [7]
Enforcement of chemical safety is the responsibility of the Health and Safety Executive (HSE), [8] which implements relevant sections of the Health and Safety at Work etc. Act 1974, formulates regulations, provides safety advice and guidance and investigates major chemical incidents.
In the US, the U.S. Chemical Safety and Hazard Investigation Board is responsible for investigating major chemical accidents and making recommendations to mitigate such events in the future.
The manufacture and purification of chemicals can involve a range of reagents which may themselves be hazardous, and a range of products which equally may be hazardous. For example, in order to produce the herbicide 2,4,5-Trichlorophenol, chlorine, an acutely toxic gas, is reacted with phenol, a hazardous organic liquid. The output is typically a mixture of chlorinated organic compounds, only some of which is the desired product. In this example, contaminants can include 2,3,7,8-tetrachlorodibenzodioxin, a dioxin, one of the most toxic synthetic chemicals known which is both acutely and chronically toxic and teratogenic and whose use on one occasion led to the abandonment of the Times Beach, Missouri. This reaction was also the cause of the infamous Bhopal disaster, during which the highly poisonous gas methyl isocyanate was released.
Major chemical accidents (and events that have the potential to escalate to major accidents) are covered in the specialized domain of process safety.
Laboratories in schools, university, research establishments and manufacturing typically store and handle a wide range of chemicals. Safety standards for such areas are high and most laboratories provide specific infrastructure to minimise risk including fume cupboards, impervious and inert work surfaces, emergency shower stations, emergency eye wash stations, and strict policies on the wearing of appropriate PPE.
There are many hazardous chemicals in routine use in the domestic environment including cleaning agents such as bleach and caustic soda. Some modern cleaning formulations also contain sodium silicate and other highly alkaline components. Modern packaging into "pods" may increase the risk of misuse, particularly for small children. [9]
Surplus hazardous materials often reach the waste stream , whether by being placed in the solid waste stream or being flushed away down sinks, basins or toilets. Although dilution may reduce the immediate risk, the long term environmental risk remains and can be made more serious as more hazardous materials are disposed of in the waste water stream. Disposal with solid waste poses risks to those handling the waste and may pose unexpected risks to uninformed members of the public. Some industrial waste chemical dumps have been known to spontaneously ignite, [10] years after the waste had been deposited. Aluminium dross processing can produce a flux-rich waste that evolves ammonia gas if wetted, and can also spontaneously ignite when stored in bulk. [11] [12] [13]
Basic chemical safety practice includes wearing protective personal protective equipment such as safety goggles. Personal protective equipment alone does not provide sufficient protection from the risks posed by hazardous chemicals but it helps minimize the risk of exposure in controlled environments. Safety googles are required when handling chemicals to prevent chemicals from getting into the eyes. Wearing standard gloves, closed-toed shoes, long trousers, and laboratory coats to protect the stomach, back and forearm is usually required in laboratories, [2] with similar provisions for other workplaces. Regulation of use of PPE is varies by country.
For most of the world, a standard set of illustrative pictograms have been adopted to indicate where hazards exists and the type of hazard present. These pictograms are routinely displayed on containers, transport vehicles, safety advice and anywhere where the material occurs. These have been extended and standardized as the Globally Harmonized System of Classification and Labelling of Chemicals and are now used throughout much of the world.
In the U.S., an NFPA diamond is used to identify chemical hazards such as flammability, corrosivity, toxicity, and reactivity. This label is made up of four colour-coded fields: red (flammability), blue (health hazard), yellow (chemical reactivity), and white (special hazard). The numbering ranges from 0 to 4 (for colours except white), with 0 meaning there is no potential hazard and 4 indicating the chemical is extremely hazardous.
Manufacturers provide a material safety data sheet (MSDS; also 'safety data sheet', SDS) for each hazardous chemical they produce. MSDSs are typically used and affixed by regulation at worksites handling those chemicals. An MSDS includes workplace health aspects, restrictions, emergency numbers, and other safety information. [14]
In a number of countries, the Hazchem system is used whenever a potentially hazardous cargo is transported whether by road, rail, sea or air. A standardized Hazchem sign affixed on the vehicle provides details of the material being transported, the nature of the hazard and the approved emergency response.
Chemical waste is any excess, unused, or unwanted chemical. Chemical waste may be classified as hazardous waste, non-hazardous waste, universal waste, or household hazardous waste, each of which is regulated separately by national governments and the United Nations. Hazardous waste is material that displays one or more of the following four characteristics: ignitability, corrosivity, reactivity, and toxicity. This information, along with chemical disposal requirements, is typically available on a chemical's Safety Data Sheet (SDS). Radioactive and biohazardous wastes require additional or different methods of handling and disposal, and are often regulated differently than standard hazardous wastes.
Toxic waste is any unwanted material in all forms that can cause harm. Mostly generated by industry, consumer products like televisions, computers, and phones contain toxic chemicals that can pollute the air and contaminate soil and water. Disposing of such waste is a major public health issue.
A safety data sheet (SDS), material safety data sheet (MSDS), or product safety data sheet (PSDS) is a document that lists information relating to occupational safety and health for the use of various substances and products. SDSs are a widely used type of fact sheet used to catalogue information on chemical species including chemical compounds and chemical mixtures. SDS information may include instructions for the safe use and potential hazards associated with a particular material or product, along with spill-handling procedures. The older MSDS formats could vary from source to source within a country depending on national requirements; however, the newer SDS format is internationally standardized.
Chemical hazards are hazards present in hazardous chemicals and hazardous materials. Exposure to certain chemicals can cause acute or long-term adverse health effects. Chemical hazards are usually classified separately from biological hazards (biohazards). Chemical hazards are classified into groups that include asphyxiants, corrosives, irritants, sensitizers, carcinogens, mutagens, teratogens, reactants, and flammables. In the workplace, exposure to chemical hazards is a type of occupational hazard. The use of personal protective equipment may substantially reduce the risk of adverse health effects from contact with hazardous materials.
Dangerous goods (DG), are substances that are a risk to health, safety, property or the environment during transport. Certain dangerous goods that pose risks even when not being transported are known as hazardous materials. An example for dangerous goods is hazardous waste which is waste that has substantial or potential threats to public health or the environment.
A waste collector, also known as a garbage man, garbage collector, trashman, binman or dustman, is a person employed by a public or private enterprise to collect and dispose of municipal solid waste (refuse) and recyclables from residential, commercial, industrial or other collection sites for further processing and waste disposal. Specialised waste collection vehicles featuring an array of automated functions are often deployed to assist waste collectors in reducing collection and transport time and for protection from exposure. Waste and recycling pickup work is physically demanding and usually exposes workers to an occupational hazard.
A chemical accident is the unintentional release of one or more hazardous chemicals, which could harm human health and the environment. Such events include fires, explosions, and release of toxic materials that may cause people illness, injury, or disability. Chemical accidents can be caused for example by natural disasters, human error, or deliberate acts for personal gain. Chemical accidents are generally understood to be industrial-scale ones, often with important offsite consequences. Unintended exposure to chemicals that occur at smaller work sites, as well as in private premises during everyday activities are usually not referred to as chemical accidents.
Environmental hazards are those hazards that affect biomes or ecosystems. Well known examples include oil spills, water pollution, slash and burn deforestation, air pollution, ground fissures, and build-up of atmospheric carbon dioxide. Physical exposure to environmental hazards is usually involuntary
The European Chemicals Agency is an agency of the European Union working for the safe use of chemicals. It manages the technical and administrative aspects of the implementation of the European Union regulation called Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH). ECHA is the driving force among regulatory authorities in implementing the EU's chemicals legislation. ECHA has to ascertain that companies comply with the legislation, advances the safe use of chemicals, provides information on chemicals and addresses chemicals of concern. It is located in Helsinki, Finland. ECHA is an independent and mature regulatory agency established by REACH. It is not a subsidiary entity of the European Commission.
Electronic waste describes discarded electrical or electronic devices. It is also commonly known as waste electrical and electronic equipment (WEEE) or end-of-life (EOL) electronics. Used electronics which are destined for refurbishment, reuse, resale, salvage recycling through material recovery, or disposal are also considered e-waste. Informal processing of e-waste in developing countries can lead to adverse human health effects and environmental pollution. The growing consumption of electronic goods due to the Digital Revolution and innovations in science and technology, such as bitcoin, has led to a global e-waste problem and hazard. The rapid exponential increase of e-waste is due to frequent new model releases and unnecessary purchases of electrical and electronic equipment (EEE), short innovation cycles and low recycling rates, and a drop in the average life span of computers.
The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is an internationally agreed-upon standard managed by the United Nations that was set up to replace the assortment of hazardous material classification and labelling schemes previously used around the world. Core elements of the GHS include standardized hazard testing criteria, universal warning pictograms, and safety data sheets which provide users of dangerous goods relevant information with consistent organization. The system acts as a complement to the UN numbered system of regulated hazardous material transport. Implementation is managed through the UN Secretariat. Although adoption has taken time, as of 2017, the system has been enacted to significant extents in most major countries of the world. This includes the European Union, which has implemented the United Nations' GHS into EU law as the CLP Regulation, and United States Occupational Safety and Health Administration standards.
The Control of Substances Hazardous to Health Regulations 2002 is a United Kingdom Statutory Instrument which states general requirements imposed on employers to protect employees and other persons from the hazards of substances used at work by risk assessment, control of exposure, health surveillance and incident planning. There are also duties on employees to take care of their own exposure to hazardous substances and prohibitions on the import of certain substances into the European Economic Area. The regulations reenacted, with amendments, the Control of Substances Hazardous to Work Regulations 1999 and implement several European Union directives.
Right to know is a human right enshrined in law in several countries. UNESCO defines it as the right for people to "participate in an informed way in decisions that affect them, while also holding governments and others accountable". It pursues universal access to information as essential foundation of inclusive knowledge societies. It is often defined in the context of the right for people to know about their potential exposure to environmental conditions or substances that may cause illness or injury, but it can also refer more generally to freedom of information or informed consent.
Workplace health surveillance or occupational health surveillance (U.S.) is the ongoing systematic collection, analysis, and dissemination of exposure and health data on groups of workers. The Joint ILO/WHO Committee on Occupational Health at its 12th Session in 1995 defined an occupational health surveillance system as "a system which includes a functional capacity for data collection, analysis and dissemination linked to occupational health programmes".
A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would potentially allow them to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific incident, combined with the magnitude of potential harm, make up its risk. This term is often used synonymously in colloquial speech.
Pesticide regulation in the United States is primarily a responsibility of the Environmental Protection Agency (EPA). In America, it was not till the 1950s that pesticides were regulated in terms of their safety. The Pesticides Control Amendment (PCA) of 1954 was the first time Congress passed guidance regarding the establishment of safe limits for pesticide residues on food. It authorized the Food and Drug Administration (FDA) to ban pesticides they determined to be unsafe if they were sprayed directly on food. The Food Additives Amendment, which included the Delaney Clause, prohibited the pesticide residues from any carcinogenic pesticides in processed food. In 1959, pesticides were required to be registered.
Many laboratories contain significant risks, and the prevention of laboratory accidents requires great care and constant vigilance. Examples of risk factors include high voltages, high and low pressures and temperatures, corrosive and toxic chemicals and chemical vapours, radiation, fire, explosions, and biohazards including infective organisms and their toxins.
Occupational toxicology is the application of toxicology to chemical hazards in the workplace. It focuses on substances and conditions that people may be exposed to in workplaces, including inhalation and dermal exposures, which are most prevalent when discussing occupational toxicology. These environmental and individual exposures can impact health, and there is a focus on identifying early adverse affects that are more subtle than those presented in clinical medicine.
The health and safety hazards of nanomaterials include the potential toxicity of various types of nanomaterials, as well as fire and dust explosion hazards. Because nanotechnology is a recent development, the health and safety effects of exposures to nanomaterials, and what levels of exposure may be acceptable, are subjects of ongoing research. Of the possible hazards, inhalation exposure appears to present the most concern, with animal studies showing pulmonary effects such as inflammation, fibrosis, and carcinogenicity for some nanomaterials. Skin contact and ingestion exposure, and dust explosion hazards, are also a concern.
Hazard substitution is a hazard control strategy in which a material or process is replaced with another that is less hazardous. Substitution is the second most effective of the five members of the hierarchy of hazard controls in protecting workers, after elimination. Substitution and elimination are most effective early in the design process, when they may be inexpensive and simple to implement, while for an existing process they may require major changes in equipment and procedures. The concept of prevention through design emphasizes integrating the more effective control methods such as elimination and substitution early in the design phase.