Report ecotoxicity studies


This CRED reporting checklist was developed to help researchers design, perform and report ecotoxicity studies in a transparent way that fulfill the reliability criteria for regulatory risk assessment. Not all criteria apply to all studies.


1 General information
a Purpose of study
b Description of endpoints
2 Test setup
a Performed according to standard/modified standard (e.g., OECD, US EPA)
b Performed according to Good Laboratory Practices (GLP) 
c Description of used control(s): negative control, solvent control, positive control 
d Control(s) mortality, growth, morbidity and other observed non-standard effects like behavior and coloring
e Comparison to validity criteria (e.g. control survival, growth) from appropriate standard test method 
3 Test compound
a Identification (e.g. name, CAS-number, specify if the salt or the base is tested)
b Physico-chemical characteristics that may influence the behavior of the compound during the study data (e.g. solubility, volatility, stability (hydrolysise, photolysise, degradation), solubility, log KOW, degradability, adsorption)
c Source
d Purity in %
e Composition of product formulation, and presence of impurities
4 Test organism
a Scientific name
b Body weight, length
c Age/life-stage
d Growth/reproductive condition
e Sex
f Strain, clone
g Source, including possible pre-exposure for field-collected species
h Culture handling
5 Exposure conditions
a Exposure schedule (static, semi static, flow through system, other) and flow-rate (flow-through systems) or renewal time (semi-static systems) 
b Open or closed system 
c Test medium composition and source of test water (e.g., well water, deionised water, tap water)
d Temperature, and time-points for measuring
e pH, and time-points for measuring
f Hardness of water, and time-points for measuring
g Conductivity, and time-points for measuring
h Dissolved oxygen content, and time-points for measuring
i Light intensity and quality (source and homogeneity), light/dark conditions
j Feeding protocols, food composition
k Material and volume of aquarium/container and other equipment in contact with test organisms and test substance
l Use of sand or sediment, and its characteristics (total organic carbon (TOC), particle size, etc.)  
m Preparation of stock solutions, including solvent concentrations in test water and controls  
n Nominal concentrations of test substance
o Measured concentrations of test substance, and time-points for measuring 
p Analytical method: description of method, including limit of detection (LOD), limit of quantification (LOQ)
q Exposure duration and total test duration
r Time-points of observations for endpoints
s Results based on nominal or measured concentrations 
t Biomass loading (biomass per liter)
6 Statistical Design and Biological Response
a Number of replicates for control(s) and test concentrations; setup of replicates (avoid pseudo-replication) 
b Number of organisms, or algal cell concentration, per replicate
c Treatment design (e.g., block, randomized)
d Statistical method used
e Biological response for each concentration 
f Dose-response observed
g Statistically significant responses noted (e.g. ECx)
h Significance level for NOEC and LOEC data (0.05 or less)
i Estimation of variability for LCx and ECx data

Availability of raw data: through supplementary information, a website, or upon request.




Reference: Download the CRED reporting checklist for ecotoxicity studies from Moermond et al. 2015 (excel sheet in Supporting Information, open access). 

Contact: Marlene Ågerstrand,