Toxicity and fate in the terrestrial environment
It is very important to carefully consider the content of organic carbon in both soil and sediment. Organic carbon can influence organism health, and can also affect test substance bioavailability. In many tests, it is necessary to allow equilibration of the test substance spiked to the soil or sediment for several days to mimic environmentally relevant aging conditions.
Examples of organisms commonly used in terrestrial toxicity tests
- Plants (e.g. lettuce, radish, rye grass)
- Worms (earthworms, oligochaetes)
Ecotoxicity assessment relies on a number of
defined tests on sediments and soil
Sediment toxicity tests
Sediment tests are primarily performed on invertebrates which will either burrow into, or ingest sediment, and as with aquatic tests, employ standard test protocols developed for a wide variety of different species including amphipods, insects, worms and oligochaetes. Control (clean artificial or natural) sediment can be spiked with a test chemical, or a contaminated natural sediment can be tested.
Exposures range from 10 to 30 days, with renewal of the overlying water during extended periods. Endpoints evaluated in sediment tests can consist of survival (LC50), growth and development (EC50), and reproduction (egg production and number of young produced).
Terrestrial toxicity tests
As with aquatic toxicity tests, a variety of species have been identified which are used as standard test organisms in terrestrial studies. These studies are focused on plants and animals which live in soil and also on birds (avian). OECD guidelines have been developed for acute toxicity studies using plants (OECD 208), earthworms (OECD 207), and birds (OECD 205). The plant toxicity studies allow the use of a very long list of species, most of which are grains or vegetables of commercial value.
The acute studies relate the concentration of the chemical or diet to the mortality of the test organism or to germination in the case of plants. Chronic guidelines for tests with birds, earthworms and the collembolan Folsomia candida have also been defined. These tests examine the effect of the chemical upon reproduction.
In this section
Basics of flammability
- Chemistry and physics of fire
- Physical properties and flammability limits
- Flash and fire points
- Auto ignition temperature
- Ignitability and minimum ignition energy (MIE)
- Static electricity
Guidelines for safe operations
- Limit the concentration of flammable fluid in air
- Reduce oxygen content
- Eliminate ignition source
- Safe handling of Exxsol™ Pentane
- Safe use and handling of hoses and flexible connections in the solvents industry
- Basics of flammability
Basics of human toxicology
- Key concepts of toxicology
- Toxicity test methods
- Testing for human relevance
- Expression of results
- Animal welfare
- Testing guidelines and GLP
Toxicology studies and data
- ExxonMobil Chemical fluids
- Jayflex™ plasticizers
- Exxal™ alcohols
- ExxonMobil™ neo acids
- ExxonMobil™ higher olefins
Human exposure assessment
- Key concepts
- Assessment methodology
- Occupational exposure assessment
- Consumer exposure assessment
- Community exposure assessment
- VOCs and indoor air quality
- Basics of human toxicology
Basics of ecotoxicology
- Key concepts
- Physicochemical properties of substances
- Standardized laboratory testing
- Toxicity and fate in the aquatic environment
- Toxicity and fate in the terrestrial environment
- Environmental exposure assessment
- VOCs and outdoor air quality
- Basics of ecotoxicology
- Safety data sheets
Single or short-lived, possibly severe, cf. chronic.
The adverse effect resulting from a brief or single exposure to a material.
Pertaining to birds.
The availability of a material in a medium for use in biological processes ; may be less than its total physical availability, if not fully soluble.
Repeated or prolonged, cf. acute.
The concentration of a material in an exposure medium (air or water) which, over a specified period of time, will produce a specific effect or endpoin... Read more
The capacity of a material or process to adversely affect the environmental species, populations or ecosystems.
A biological change caused by, or related to, an exposure.
The concentration of a material in an exposure medium (air or water) which, over a specified period of time, will kill 50% of an exposed species.
Organization for Economic Co-operation and Development
The probability that harm will occur as a consequence of exposure during use of a chemical, physical or biological agent.
The identification and analysis of the hazards, likely or actual exposures thereto, and the subsequent risks, to which a population or ecosystem is or... Read more
A chemical element or its compounds in its natural state or obtained by any production process.
The capacity of a material or process to affect human health or the environment ; the inherent properties of a chemical, physical or biological agent ... Read more