Acute toxicity test

In tests for acute toxicity the exposure time and the observed period are comparatively short in relation to the life cycle of the test organisms used (usually max. 96 hours).

Adsorption

Enrichment of one or more components in an interfacial layer.

Adverse effect

Change in morphology, physiology, growth, development or lifespan of an organism.

BCF

Bioconcentration factor showing the ratio between the concentration in an organism and the concentration of a substance in the ambient environment (typically water).

Bioaccumulation

the net result of the uptake, distribution, and elimination of a substance due to all routes of exposure.

Bioconcentration

the net result of the uptake, distribution, and elimination of a substance due to water-borne exposure.

Biodegradation

see degradation

Biotransformation

see transformation

BOD

Biological Oxygen Demand.

Chronic toxicity test

Toxicity determined in tests covering the life cycle of an organism or at least the most sensitive life stages.

Degradation

conversion of a molecule to smaller molecules by biological (micro-organisms) or chemical action.

Degradation rate

the rate at which a chemical compound ca be degraded. Often expressed as a DT50 (time at which 50% of the parent compound has disappeared from soil or water by transformation or degradation.

Dissipation

disappearance of the parent compound from a compartment (water or soil) in which various processes such as conversion, evaporation leaching, etc. can participate.

DO

Dissolved Oxygen

DOC

Dissolved Organic Compound

Dose-response

the estimation of the relationship between a dose or concentration and the assessment incidence and severity of an effect.

DT50

time in which 50% of the parent compound has disappeared from soil or water by transformation or degradation.

Dung

faeces from grazing animals.

EC50

Effect concentration resulting in 50% effects (e.g. growth inhibition) in a group of laboratory organisms after a given exposure time.

Effect assessment

concerns the hazard identification and dose-response assessment.

Environmental hazard

The EU system for the classification of chemical substances on the basis classification of their environmental properties.

Exposure assessment

the determination of the emission, pathways and rates of movement of a substance and its transformation or degradation products in order to estimate the concentrations/doses to which ecological systems and populations are or may be exposed.

EUSES

European Uniform System for the Evaluation of Substances, a decision-support system, including models for calculation of exposure and hazard in environmental compartments.

Guideline

an official Guideline (i.e. authorised by national or international institutions. e.g. EPA, NEN, BBA, OECD) for the protocol and the report of a test.

Hazard

the inherent potential of a substance to cause adverse effects

Hazard assessment

the process designed to estimate the incidence and severity of the adverse effects likely to occur in an environmental compartment due to actual or predicted exposure.

Hydrolysis

a chemical reaction of a substance with water in which a part of the molecule of the reacting substance is replaced by an OH group.

LC50

Effect concentration involving 50% mortality in a group of laboratory organisms after a given exposure period.

LD50

Effect dose involving 50% mortality in a group of laboratory organisms after a given exposure period.

Leaching

transfer of a chemical from the top layer of soil to the subsoil.

log Kow

The logarithm of the octanol-water partition coefficient.

Manure

mixture of faeces and urine produced by housed animals. When mixed with dirty water, the mixture is denoted slurry.

Metabolite

substance formed from the parent compound by chemical transformation.

Mineralisation

degradation of a substance into inorganic end products; it is usually estimated in terms of CO2 production.

NOEC

No-Observed-Effect-Concentration; the highest test substance concen-tration without adverse effects.

PEC

Predicted Environmental Concentration; the expected concentration in an environmental compartment.

Photochemical

breakdown of a compound as a result of irradiation by light. transformation

Risk

Probability of a substance to cause adverse effects.

Risk estimation

the quantitative estimation of the probabilities of clearly described effects by including uncertainty analysis.

TOC

Total Organic Carbon.

transformation

conversion of a molecule to larger or smaller molecules by (micro)biological or chemical action.