Topic Areas included are:

1 Properties
2 Regulations
3 Manufacture
4 Acute Toxicity: Terrestrial Animals
5 Acute Toxicity: Humans
6 Acute Toxicity: Aquatic Animals
7 Chronic Toxicity: Terrestrial Animals
8 Chronic Toxicity: Humans
9 Chronic Toxicity: Aquatic Animals
10 Phytotoxicity
11 Carcinogenicity
12 Mutagenicity
13 Reproductive and Developmental Effects: Terrestrial Animals
14 Other Adverse Effects
15 Pharmacokinetics/Metabolism
16 Bioaccumulation/Bioconcentration
17 Transport Process
18 General Fate Processes
19 Transformation Processes
20 Analysis and Treatment
21 References
22 Topic Area Summaries
23 Ontario Environmental Assessment

1. Properties - Physical And Chemical

Explanations of the tests and measureents found in some of the fields in the Properties Topic Area are presented below, along with the sources of information, when appropriate.

Aqueous Solubility
Autoignition Point
Biochemical Oxygen Demand
Boiling Point
Chemical Oxygen Demand
Conversion Factor
Density
Explosive Limits
Flash Point
Henry's Law Constant
Melting Point
Molecular Formula
Molecular Weight
n-octonal/Water Partition Coefficient
Odor Threshold - Air
Odor Threshold - Water
Physical State at STP
PKA - Acid Dissociation Constant
Specific Gravity
Taste Threshold
Theoretical Oxygen Demand
Vapor Pressure

Molecular Formula The molecular formula of the chemical is given in Hill order: the number of carbon atoms are presented first, followed by the hydrogen atoms, and then by the remaining elements in alphabetical order.

Molecular Weight The unitless formula weight is reported in this field, which is the sum of the atomic weights of all atoms shown by the empirical formula of a substance.

Sources include: CRC Handbook of Chemistry and Physics.

Physical State at STP Indicates the physical state of the material (gas, liquid, solid) at standard temperature and pressure - 0 degree C and 1 atmosphere pressure (the pressure exerted by the air at sea level, which will support a column of mercury 760 mm high). Sources include: The Merck Index.

Melting Point The temperature at which the solid and liquid phases of a given substance are in equilibrium is the melting point of a solid, or the freezing point of a liquid. The temperature is reported in degrees C at standard pressure (760 mm).

Sources include: CRC Handbook of Chemistry and Physics.

Boiling Point The temperature in degrees C at which the rate of molecular motion is sufficient to result in the escape of molecules from the surface of a liquid at standard pressure (760 mm). Sources include: CRC Handbook of Chemistry and Physics.

Flash Point The temperature in degrees C at which a liquid (or volatile solid) gives off sufficient vapor to form an ignitable mixture with air near the surface of a substance. If available, test methods are indicated:

oc (open cup),
cc (closed cup),
ccc (Cleveland closed cup),
coc (Cleveland open cup).

Sources include: Fire Protection Guide on Hazardous Materials.

Autoignition Point The minimum temperature in degrees C required to initiate or cause self-sustained combustion of a substance (solid, liquid, or gas) independently of the heating or heated element.

Sources include: Fire Protection Guide on Hazardous Materials.

Explosive Limits For gases or vapors which form flammable mixtures there is a range of concentration in which explosion can occur upon contact with a source of ignition. Below the minimum concentration of vapor in air or oxygen (or above the maximum concentration) propagation of flame does not occur. These two boundary lines, or explosive limits, are expressed in terms of percentage by volume of gas or vapor in the air.

Sources include: Fire Protection Guide on Hazardous Materials.

Density The density is reported as mass per unit volume (g/ml) of a compound at standard temperature unless otherwise specified.

Sources include:CRC Handbook of Chemistry and Physics.

Specific Gravity Denotes the ratio of the mass of a substance to the mass of an equal volume of a reference substance. The reference substance is water for solids and liquids. The temperature is specified in degrees C.

Sources include: The Condensed Chemical Dictionary.

Henry's Law Constant Reports the weight of a gas that dissolves in a definite volume of liquid relative to the partial pressure value in the air. Values are reported in atm m3/mole.

Sources include: Quantitative Structure Activity Relationship (QSAR) database; Handbook of Chemical Property Estimation Methods.

PKA: Acid Dissociation Constant The PKA (pKa) is the equilibrium constant established between the undissociated and dissociated components of a compound in aqueous solution under standard conditions.

Sources include: Quantitative Structure Activity Relationship (QSAR) database; primary references.

Theoretical Oxygen Demand The theoretically derived total quantity of oxygen needed to completely oxidize a compound to carbon dioxide and water. It is usually reported as grams oxygen per gram of compound or as milligrams oxygen per litre of sample.

Sources include: Handbook of Environmental Data on Organic Chemicals.

Biochemical Oxygen Demand The quantity of oxygen required by microorganisms to oxidize organic compounds in a water sample. The test is conducted for five days at 20 degrees C with the oxygen consumption determined by direct measurement of the dissolved oxygen at the beginning and end of the test. Results are usually reported as milligrams of oxygen required per litre, as grams of oxygen required per litre, or as grams of oxygen required per gram of compound.

Sources include: Handbook of Environmental Data on Organic Chemicals.

Chemical Oxygen Demand The quantity of oxygen required to completely oxidize both the organic and inorganic material present in water as determined by the Chemical Oxygen Demand Test. The test measures the oxygen equivalent to that portion of the organic matter in a sample which can be oxidized by a strong chemical oxidant (potassium dichromate and sulfuric acid). Results are generally expressed as milligrams oxygen per litre of sample, or as grams of oxygen per gram of compound.

Sources include: Handbook of Environmental Data on Organic Chemicals.

Conversion Factor The numerical value for converting units from relative volume measurements (i.e., parts per million) in air to mass per unit volume (milligrams per cubic metre). This factor is dependent on the density of the chemical in question and is reported for a temperature of 20 degrees C and 760 mm Hg unless otherwise stated.

Sources include: Documentation of the Threshold Limit Values for Substances in Workroom Air; Patty's Industrial Hygiene and Toxicology.

Odor Threshold - Air The lowest concentration at which a chemical in air is detectable by the sense of smell. No standard methods are established for performing this test and ambient conditions may greatly affect the results.

Sources include: Handbook of Environmental Data on Organic Chemicals.

Odor Threshold - Water The lowest concentration of a chemical in water that is detectable by the sense of smell. No standard methods are established for performing this test and ambient conditions may greatly affect the results.

Sources include: Handbook of Environmental Data on Organic Chemicals.

Taste Threshold The lowest concentration in water at which the taste of a chemical is detectable. The threshold may be identified in the water directly or in fish or shellfish inhabiting the water. No standard methods are established for performing this test and ambient conditions may greatly affect the results.

Sources include: Handbook of Environmental Data on Organic Chemicals; Impairment of the Flavor of Fish by Water Pollutants.

Aqueous Solubility The aqueous solubility of a given solute is defined as the quantity of that solute which dissolves in a specified quantity of water to produce a saturated solution at a specified temperature.

Sources include: Handbook of Environmental Data on Organic Chemicals

Vapor Pressure Reports the pressure exerted by the vapor at equilibrium with its liquid form, at a given temperature. Standard vapor pressure units are millimetres of mercury (mmHg) or Torr.

Sources include: Handbook of Environmental Data on Organic Chemicals

n-Octanol/Water Partition Coefficient The partition coefficient is the ratio between the equilibrium concentrations of a given solute in the n-octanol and water fractions of a biphasic test vessel. The coefficient is measured by quantitative analysis of the chemical solute concentrations in the n-octanol phase and the water phase; it is also possible to estimate the ratio using empirically derived relationships based on structural fragments of the molecule in question. The CLOGP model algorithms are commonly used to estimate a Kow value. The partition coefficient in CESARS is recorded as the base 10 logarithm of the n-octanol/water concentration (Log Kow).

Sources include: Substituent Constants for Correlation Analysis in Chemistry and Biology; QSAR data base system.

2. Regulations And Guidelines

This Topic Area originally contained regulatory information and guidelines from the United States Federal Government and its agencies. In future, Canadian and international information will be made available. Acceptable levels in the environment, emission control requirements, waste disposal requirements, occupational health and safety guidelines, labeling and transportation regulations are included.

Information in this Topic Area is not routinely collected.

3. Manufacture

Describes the uses, occurrence, production and methods of synthesis for the chemical.

4. Acute Toxicity - Terrestrial Animals

Acute toxicity refers to adverse effects on terrestrial life forms (excludes humans) elicited by test compounds after a single exposure or multiple doses within 24 hours.

The median lethal dose (LD50) refers to the dose of a substance that can be expected (statistically) to be lethal to 50% of animals exposed. The median lethal concentration (LC50) is the concentration of a substance that can be expected (statistically) to be lethal to 50% of exposed animals after a specified exposure duration. In this Topic Area the LC50 applies only to exposures via inhalation.

5. Acute Toxicity - Human

Acute toxicity refers to adverse effects on humans elicited by test compounds after a single exposure or multiple doses within 24 hours.

Sources of information are usually generalized discussions, as found in secondary references and reviews.

6. Acute Toxicity - Aquatic Animals

The acute toxicity studies are undertaken on freshwater aquatic species. Median lethal concentrations (LC50) or median effect concentrations (EC50) for fish and aquatic macroinvertebrates are reported. EC50's refer to the combined total percentage of:

1. organisms immobilized,
2. organisms exhibiting loss of equilibrium,
3. animals killed.

The 95% confidence interval is for the LC50 or EC50. The types of studies reported are generally 1 to 7 day acute lethality tests using continuous flow exposure or static exposure. The test concentrations can be either measured or unmeasured (nominal). Data on saltwater species are sometimes collected.

7. Chronic Toxicity - Terrestrial Animals

This Topic Area reports subchronic (subacute) and chronic toxicity studies of terrestrial animals conducted to determine adverse effects following repeated administration of a compound.

Exposure duration in subchronic studies may range from 2 to 90 days (approx. 10% of lifetime); a chronic study approximates the full lifetime or a significant portion thereof. The dose is listed in standard units of mg/kg/d (actual daily dose) for all administration routes. "Terrestrial animals - NOAELs" refer to No-Observed-Adverse-Effect- Levels, which are reported in standard units of mg/kg/d.

8. Chronic Toxicity - Human

This Topic Area reports subchronic (subacute) and chronic toxicity studies of humans conducted to determine adverse effects following repeated exposure to a compound. The dose is listed in the units as reported in the study. NOAELs refer to No-Observed-Adverse-Effect- Levels, which are reported in the units given in the study.

9. Chronic Toxicity - Aquatic Animals

This Topic Area contains information about chronic toxicity studies for freshwater aquatic species. The Maximum Adverse Toxicant Concentrations (MATC), the Highest-No-Observed-Adverse-Effect-Level (HNOAEL), and the Lowest-Observed-Adverse-Effect-Level (LOAEL) are reported for fish and aquatic macroinvertebrates.

The types of studies recorded fall into one of three categories: 1) life cycle (LC), 2) partial life cycle (PLC) or early life stage (ELS), 3)embryo-larval tests (E-L). The test concentrations must be measured, rather than just estimated for the studies to be included in CESARS.

A chronic value (MATC) is obtained by calculating the geometric mean of the lower and upper limits from a chronic test.

Data on saltwater species are collected occasionally.

10. Phytotoxicity

Contains information on the effects of substances on aquatic and terrestrial plants.

11. Carcinogenicity

Summaries of carcinogenicity determination studies conducted by the following organizations are included:

1. NCI National Cancer Institute/National Toxicology Program
2. IARC International Agency for Research on Cancer (Working Group)
3. NIOSH National Institute of Occupational Safety and Health
4. U.S. EPA United States Environmental Protection Agency

For animal studies, the administered dose is in standard units of mg/m3 for the inhalation route, or mg/kg/d (actual administered daily dose) for all other routes. If the reported dose was converted to standard units by the reviewer, the dose reported by the author is included in the "Dosing schedule" column.

12. Mutagenicity

There are 3 basic categories of mutagenicity studies reported in CESARS: gene mutations, chromosomal aberrations, and DNA damage.

Gene mutations are microlesions or alterations of the gene sequence at the nucleotide level. These alterations may be base-pair substitutions (a qualitative change in nucleotide pairs) or frameshifts (base-pair additions/deletions, which are quantitative changes in nucleotide pairs).

Chromosomal mutations could be numerical (ploidy changes), involving complete loss or gain in chromosomes, or structural (clastogenic), involving chromosome or chromatid breaks, deletions, or rearrangements such as translocations or nondisjunctions.

Evidence of DNA damage may be valuable predictors of carcinogenic activity because there is increasing correlative evidence that chemicals which induce DNA damage are carcinogenic. Examples of DNA damage are missing, incorrect, or altered purine or pyrimidine bases; interstrand cross-links; and strand breaks.

13. Reproductive And Developmental - Terrestrial Animals

The dose of the chemical studied is entered in units of mg/kg/d (actual administered daily dose). A No-Observed-Adverse-Effect-Level (NOAEL), which is the highest dose level at which no observed adverse effect is seen, may be included in the author's evaluation. The NOAEL may be used to calculate exposure levels of the compound for humans and other species in various exposure situations. Human studies are included when available.

14. Other Adverse Effects

Contains information on aesthetic effects and other adverse effects for which no specific fields are available within the other topic areas.

15. Pharmacokinetics/Metabolism

This Topic Area contains information on the uptake, distribution, biotransformation, and elimination of a compound by terrestrial organisms. In vivo studies (within the plant/animal body) are generally reported.

Records are of two types:

1. brief information containing the study description (typically one or two sentences in length), and
2. full evaluation and summary of the study by the reviewer.

The expanded record will replace the brief one if, and when, it becomes available. Information for this Topic Area is not routinely collected.

16. Bioaccumulation/Bioconcentration

This Topic Area contains information about the bio-uptake (concentration and accumulation) of chemicals by aquatic organisms.

BCFs (bioconcentration factor) are reported on the basis of total body weight, organ weight, or percent lipid content of the organisms. The types of tests used are: field (FLD), flow through (FT), intermittent flow (IF), monitoring data (MON), renewal (REN), and static (ST).

17. Transport Processes

This Topic Area reports studies of chemical behavior related to transport among environmental media. This includes:

1. sorption (adsorption, absorption) of chemicals to matter suspended in water or air, soil, sediment or biota (flora and fauna), and
2. volatilization: data on the physicochemical process of chemical transfer from water or soil solutions or from solid surfaces to the atmosphere.

18. General Fate Processes

This Topic Area contains information on microcosm studies and field studies relating to environmental fate processes. Microcosm studies include those using microcosms or model ecosystems that are designed to predict the fate of the chemical in the natural environment. Field studies report the intentional release of a test compound into the environment in order to determine its behavior.

19. Transformation Processes

This Topic Area is mainly concerned with studies of:

1. biodegradation - the degradation of chemicals by microorganisms
2. hydrolysis of compounds - as conducted in the environment and the laboratory; hydrolysis is a chemical transformation process in which water reacts with another substance by cleaving chemical bond(s) to form two or more substances; this process does not include other possible reactions between chemicals and water such as acid/base reactions.

20. Analysis And Treatment

This Topic Area contains information on standard analytical techniques. Wastewater treatment, general waste treatment and drinking water treatment methods are briefly described giving removal efficacy when available.

Information for this Topic Area is not routinely collected.

21. References

Contains the references that are cited in topic areas 1 to 20.

22. Topic Area Summaries

Contains only the information from the summary fields of the CESARS record.

23. Ontario Environmental Assessment

Contains the assessment and scoring of chemicals, as prepared by the Ontario Ministry of the Environment.

The Preliminary Assessment is prepared from a quick review of secondary literature sources; the Detailed Assessment is from the information in a CESARS record.

For information on the scoring systems used see:

MOE Scoring Summary
Health Canada Mutagenicity/Genotoxicity Scoring System