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Section 12: Ecological Information
The majority of the chemicals used in workplaces generally ends up in the environment - eventually - through general use and disposal. Because of this, it's important to know which precautions you should take. To determine which precautions to take you must ensure suitable risk management is undertaken.
In Section 12 the supplier will provide information on the effects the product will have on the environment should exposure occur.
When it comes to the environment and the risk of exposure to a hazardous substance, there is something of a balance between the amount of likely exposure and the harm that would be done should that exposure occur.
Environmental Fate: The risk of a hazardous substance entering the environment and the risk of that substance accumulating (rising over time).
Environmental Effects: The hazard and its ability to harm organisms.
The information provided in this section may be very detailed, technical and difficult for a layman to read. On the other hand, it might say very little. Different suppliers will provide differing levels of information.
However, it's important that you understand this information, and the information provided in Sections 9 and 13 very well. These three sections are very closely relevant and should be used together to ensure you're able to protect the environment.
Please note: When reading Section 12, the word 'distribution' refers to the dispersion of the product through the soil, the air or water and the eventual fate of the product. Many chemicals products will break down into safe byproducts, while others will accumulate and cause harm to the environment, and still others will accumulate but cause no harm.
12.1. Toxicity
In subsection, the supplier should include data from three trophic levels (the position of an organism in the food chain).
Here are the three main trophic 'groups':
Producer (autotrophs): Producers are generally algae and plants. They do not eat other organisms but gather nutrients from their environment and produce their own food through photosynthesis. Because of this, they are known as primary producers. Producers are usually powered by the sun, however, deep under the oceans there is no sunlight and the creatures use a process called chemosynthesis (a similar process to photosynthesis, but uses the oxidation of inorganic compounds or methane as the source of energy).
Consumers (heterotrophs): Consumers are creatures which cannot produce their own food and must eat other organisms to survive. Consumers are herbivores (e.g. rabbits, giraffes, elephants, etc.) which eat plants, carnivores (e.g. foxes, eagles, tigers, lions, etc.) which eat other animals, and omnivores (e.g. badgers, hedgehogs, raccoons, monkeys, etc.) which eat both plants and others animals.
Decomposers (detritivores): Decomposers are those bacteria, fungi, vertebrates and invertebrates which consume detritus (dead particulate organic materials) and convert it into inorganic chemicals. Those inorganic chemicals are basically recycled to mineral nutrients which the Producers can then gather and use to generate food for themselves.
If something happens to one of these trophic levels, then the whole ecological balance could be severely disrupted causing serious consequences in organic populations.
Here are some examples of the information you may find here:
Material expected to be toxic to aquatic organisms. May cause long-term adverse effects in the aquatic environment.
Fishes: Median lethal ph (96h) 3-3.25 for Lepomis macrochirus (no guideline followed).
Aquatic plants:
EC50 (72h): >100mg/L test mat, (nominal) based: growth rate (OECD 201-Desmodesmus subspicatus (algae)).
NOEC (72h): 100mg/L test mat. (nominal) based on: growth rate (OECD 201-Desmodesmus subspicatus (algae)).
Aquatic invertebrates: EC50 (48h): >100mg/L test mat. (nominal) based on: immobilisation (OECD 202-Daphnia magna).
The NOEC, or 'No Observed Effect Concentration', is the test concentration which caused no obvious harmful effects in terms of death or severe behavioural changes in fish (the consumers), immobilisation in daphnia (the decomposers) and growth impairment in algae (the producers).
Tests performed are run at different test concentrations (multiple consumers or producers) in each test group and the concentration causing 50% reduction in vitality (growth rates, immobilisation rates, death rates, etc.) is known as the XC50, where X can equal L (lethal), E (effect), or I (Inhibition).
For example, tests involving algae include many thousands of algal cells and the rate at which those cells grow is measured over a set period of time (generally 3 days). It is possible, if not probable, for faces to occur in which a 10% loss of vitality, or 100% effect (the death of every fish in the specified test group) is reported.
The different test methods and an explanation of each can be found in Regulation (EC) No. 440/2008.
12.2. Persistence and Degradability
Persistence: The length of time a substance will remain in the environment (or bodily organs) after it is introduced. Whereas some substances persist for less than one second, others (such as heavy metals, pesticides, plastics) may persist indefinitely.
Degradable: (Of waste products, packing materials, etc.) capable of being decomposed (broken down) chemically or biologically; A material that will undergo a process of deterioration or breaking-up by the action of natural forces (air, light, water) or by the addition of certain chemicals.
Degradability: A measure of the extent to which something in the environment is degradable.
Degradation: (Environmental) degradation is the deterioration of the environment through the depletion of resources such as air, water and soil; the destruction of ecosystems; habitat destruction, the extinction of wildlife; and pollution.
It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable. As indicated by the I=PAT (I=P*A*T) equation, environmental impact (I) or degradation is caused by the combination of an already very large and increasing human population (P), continually increasing economic growth or per capita affluence (A), and the application of resource-depleting and polluting technology (T).
Abiotic degradation: The process in which a substance reacts with water or sunlight to form new chemicals by the processes of hydrolysis or photolysis, respectively. Resultant chemicals from these processes often present their own hazards which could be the same as or different from those of the original product. It is often the case that they are more hazardous than the original product, and extra care should be taken.
You will generally find data relating to the degradation potential of a product provided in this subsection of the safety data sheet. That data should be defined according to the following values:
Biological (chemical or bio-)degradation: The chemical degradation of contaminants by bacteria or other biological means. Organic material can be degraded aerobically (in the presence of oxygen) or anaerobically (in the absence of oxygen). It is a natural process (or a series of processes) by which spilt inorganic chemicals or other inorganic waste material can be broken down (degraded) into nutrients that can be used by other organisms.
The ability of a chemical to be biodegraded is an indispensable element in understanding the risk posed by that chemical on the environment.
Biochemical Oxygen Demand (BOD): In the case of aerobic chemical degradation, excessive oxygen consumption can have an effect on the environment. It is vitally important that the amount of oxygen (BOD) needed to breakdown a given amount of a chemical product is known. A higher BOD means that more oxygen is needed to breakdown the product and the probability that living organisms will be killed is greater.
Chemical Oxygen Demand (COD): An indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. It is commonly expressed in mass of oxygen consumed over volume of solution which in SI units is milligrams per Litre (mg/L). COD tests are used to easily quantify the amount of organics in water. The most common application of COD is in quantifying the amount of oxidisable pollutants in surface water (e.g. lakes and rivers) or wastewater.
COD is useful in terms of water quality by providing a metric to determine the effect an effluent will have on the receiving body, much like biochemical oxygen demand (defined above). The ratio of the values of BOD to the COD provides a measurement of the extent to which a substance will biodegrade. That data should be defined according to the following values:
12.3. Bioaccumulative Potential
Bioaccumulation: Successive additions of a substance that stays within a body or the environment, and is not biodegraded, excreted, or neutralised.
The bioaccumulative potential of a chemical product is an important factor. It is a direct indication of the amount of chemical product which will build up in the environment to the point that it becomes a significant (environmental) health problem.
Please note: This factor is particularly important in the case of aquatic organisms, where a chemical product can accumulate in a single organism which is then consumed. That bioaccumulation passes on to the consumer and thus, enters the local food chain.
Generally, bioaccumulation is indicated by the Octanol-Water Partition Coefficient (Kow), which is an indication of the solubility of a chemical product in fatty tissues (e.g. aquatic species), compared to the solubility of the same product in water.
Please note: The Ocatanol-Water Partition Coefficient may be represented as Kow, Log Kow, Log P or Log Pow. All three terms are equivalent.
Data provided relating to the Octanol-Water Partition Coefficient should be defined according to the following values:
Please note: Any chemical product with a Log Kow value greater than 3 is considered as having high bioaccumulative potential and thus, requires the provision of greater precautions (e.g. avoiding the release of the product into the environment).
Biomagnification: This is another effect related to the accumulation of chemical products in the environment.
An example of biomagnification:
The chemical product enters the food chain, through waterborne algae.
The accumulation concentration of the chemical increases as daphnia eat the algae.
It increases further as fish eat the daphnia.
And increases further as mammals eat the fish.
12.4. Mobility in Soil
Mobility in soil is a measurement of the way a product spreads through the environment, including the different Environmental Compartments:
Air,
Biota,
Sediments,
Soil,
Water.
Different chemical products will spread, or disperse, in different manners depending on their chemical properties and physical form:
Gas: Disperses widely into the atmosphere.
Insoluble solids: Generally, will stay where they are unless they are fine and light and thus, able to be carried by the wind.
Liquids: Can be dispersed widely through each of the Environmental Compartments, if the product is highly volatile. Otherwise, liquids will generally disperse through drains, watercourses, and soil.
Water-soluble solids: Can be dispersed widely through each of the Environmental Compartments, if the product is highly volatile when dissolved by water. Otherwise, water-soluble liquids will generally disperse through drains, watercourses and soil, when dissolved by water.
It should be noted that the more water-soluble a material is, the less likely it is to move from watercourses into soil or sediment. Liquids, likewise, are likely to flow through the watercourse instead of seeping into soil or sediment.
All of these types of chemical product can also react with certain materials in the soil or sediment. For example; clay. This subsection will contain this information if it is relevant.
12.5. Results of PBT and vPvB Assessment
PBT: Persistent, Bioaccumulative and Toxic.
vPvB: very Persistent, very Bioaccumulative.
Both PBT and vPvB are very bad for the environment, and a safety data sheet containing details regarding them mean the chemical product you are using has the potential to cause serious long-term damage to the environment and a very real risk of entering the food chain through various means.
If the chemical product is registered under REACH then an assessment of its PBT and vPvB potential must be taken before it can be assigned a REACH registration number. Assessments will relate to separate substances. In the case of a mixture of substances, the supplier may include a statement saying, 'none of the substances in this mixture are considered PBT or vPvB'.
Please note: Any substance known as PBT or vPvB are extremely dangerous to the environment and extra-special care should be taken to ensure no accidental release into the environment is allowed to happen.
12.6. Other Adverse Effects
The supplier should include any further known effects in this subsection, including comments regarding the chemical products effect on ozone depletion, or other debilitating effects on the environment or animals and humans.
Please note: Even materials classes as environmentally non-hazardous are capable of causing devastating effects. For example, a major release of something as seemingly innocuous as milk into a local river system can quickly sap the water of oxygen, causing the local fish population to suffocate and die.
Confused by the many pieces of information provided in those safety data sheets? Join the International Association for Chemical Safety's completely free health and safety academy now and take the Safety Data Sheet Awareness Certification™.
This article was originally published by the team over at Sevron Ltd and has been shared here with full permissions.