Ecotoxicity Assessment

Ecotoxicity Testing
McertsThe Ecospan Environmental team have over 20 years of experience of completing ecotoxicity testing using a wide variety of species ranging from bacterial and algal assays through to chronic fish and invertebrate testing. Ecospan Environmental Ltd is MCerts approved by the Environment Agency to undertake all Direct Toxicity Assessment (DTA) tests with marine and freshwater species.

We have extensive experience of ecotoxicity risk assessment having successfully completed such projects for a multitude of large chemical manufactures and petrochemical sites. This background provides us with the expertise to complete the Ecotoxicity assessment of production waters as required by the UK Risk Based Approach implementation programme.

Testing capabilities:
Freshwater Species Marine Species
Algal Growth inhibition test Raphidocelis subcapitata (72 hour EC50) Skeletonema costatum (72 hour EC50)
Acute invertebrate Daphnia magna (48hour LC50) Tisbe battagliai (48hour LC50)
Acartia tonsa (48hour LC50)
Subleathal invertebrate Crassostrea gigas Oyster Embryo development test (24 hour EC50)
Chronic invertebrate Daphnia magna growth and reproduction 21 day Tisbe battagliai reproduction(EC50)
Sediment reworker Corphium volutator (10 day LC50)

Direct Toxicity Assessment (DTA)DTA-vert
All complex effluent discharges to controlled waters over 10 m3 /day are required to undergo Direct Toxicity Assessment (DTA). This has been implemented by the EA and SEPA through Environmental Permitting Regulations (previously IPPC). All testing must be carried out by an MCERTS approved laboratory using designated methods. The results of these tests are used to determine the acute environmental risk associated with the discharge.


  • Algal growth test: Skeletonema costatum or Selenastrum costatum
  • Invertebrate lethality test: Tisbe battagliai or Daphnia magna
  • Oyster embryo larval development test
  • Toxicity tracking
  • Toxicity Identification Evaluation (TIE)
  • DTA environmental risk assessment
  • On-site testing

Ecospan’s staff have extensive experience in DTA, having been involved in both the demonstration project and in the development of the technical guidance. Over the years we have established a good rapport with the regulators which enables us to design testing protocols tailored to each discharge and produce risk assessments detailing the potential impacts of the effluent. Our team also have experience of critically reviewing existing data to assess its quality and ensure businesses are not burdened by unnecessary testing. This often involves undertaking a comprehensive environmental risk assessment. If chronic or population effects need to be considered (e.g. discharge into a SPA or SSSI), Ecospan can design and undertake ecological surveys to quantify any impact on the receiving environment.

On-site testing
Where toxicity could arise from multiple sources, or sites are required to investigate the sources of toxicity within their operation, our on-site testing service offers a very cost effective solution. Up to 100 samples can be tested over a working week enabling the toxicity contributions and variability from multiple drains to be fully investigated. The large number of samples that can be tested can also be used to identify the principal toxicant source(s). Additionally, toxicity identification evaluations (TIE) may be undertaken to characterise the type of toxicant present.

Recent Projects