Toxicology consulting is the practice of evaluating the potential for chemical exposures to affect human and environmental health and welfare. 

SLR professionals identify, acquire, and utilise the most up-to-date scientific information to assess intrinsic hazards of chemicals, exposures to these chemicals, and their corresponding risk to the public workers, and the environment.

How can we help?

SLR's core services for risk assessment and (eco) toxicology include: 

  • Detailed knowledge of current regulations, guidance, and underlying science. 
  • Clear understanding of our client’s goals and tailoring a scope to meet them. 
  • Conducting agency interaction and negotiation. 
  • Providing robust, pragmatic, and technically defensible human health and ecological risk assessment affording cost effective solutions. 
  • Development and/or assessment of health-based guidelines for chemicals 
  • Litigation support in toxicological matters. 
  • Hazardous substance and dangerous goods classification for mining concentrates, coal, and other related products.

Our team

  • Dr Mark Stelljes Director of Risk Assessment and Toxicology
    Dr Mark Stelljes

    Mark Stelljes has 30 years of experience in risk assessment consulting, as well as another seven years of experience in the fields of pharmacology, toxicology, zoology, and ecology. This experience has included managing, directing, and conducting human health and ecological risk assessments for a variety of private and government clients in North America for projects ranging from dry cleaners to military facilities and mine sites. 

  • Dr Jeff Peterson Principal Scientist
    Dr Jeff Peterson

    Jeff Peterson has over 27 years of experience managing projects that assess risks hazardous substances may pose to human health and the environment. He also provides clients and project managers with strategic and regulatory guidance. His areas of specialty include ecology, toxicology, and statistics. Jeff has performed over one hundred risk assessments for numerous facilities, including oilfields, landfills, airports, and a diverse array of industrial sites. On behalf of private companies and municipalities, he has negotiated favorable outcomes with a variety of state and federal regulatory agencies.

Toxic Release Inventory Reporting: Screening and Sampling for PFAS Chemicals

Toxic Release Inventory Reporting: Screening and Sampling for PFAS Chemicals

Annika Wallendahl Principal
Annika Wallendahl

Annika has over 15 years of environmental compliance and project management experience in the industrial and manufacturing sectors across the U.S. She specialises in environmental compliance, permitting, training and auditing at industrial facilities and is a licenced professional engineer and geologist.

As a former environmental manager at an industrial facility, she has a deep understanding of industrial facility CAPEX approval processes, timelines, procurement requirements, and project execution.

She has prepared corporate sustainability reports with emphasis on climate change initiatives; and provided cost estimates and return on investment estimates for “green projects” such as fossil fuel reduction projects and waste minimisation.

excess oil

The dirt on the new Ontario Excess Soil Regulations

Kathryn Matheson Risk Assessor
Kathryn Matheson

Kathryn is a Qualified Person in Risk Assessment in Ontario with over 11 years of consulting experience in risk assessments, soil vapour assessments, Phase I and Phase II environmental site assessments and remediation activities. Kathryn has been involved in the preparation and peer review of numerous Human Health and Ecological Risk Assessments, Environmental Site Assessment and Remediation projects under guidance from the Canadian Council of Ministers of the Environment (CCME), Health Canada and the Canadian Standards Association (CSA) as well as various provincial and territorial bodies (ON, BC, AB, SK, MB, YK).