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Principal PFAS Toxicologist

GSI Environmental


Job Location:

Houston, TX - USA

Monthly Salary: Not provided by the employer
Posted: 1 June 2026 (30+ days ago)
Application Deadline: 29 August 2026
Vacancies: 1 Vacancy
The job posting is outdated and position may be filled

Job Summary

Description

Position Overview

GSI Environmental Inc. (GSI) seeks a highly experienced Principal PFAS Toxicologist to join our growing team. This leadership role will drive technical excellence mentor associate staff and lead multidisciplinary teams involving toxicology health sciences and environmental risk assessment in support of regulatory compliance and litigation matters.

The right candidate will enjoy a generous compensation and benefits package the opportunity for a substantial performance-based bonus meaningful ownership in a growing highly profitable privately-owned firm the ability to participate in firm leadership and the freedom to develop a practice within a supportive and collaborative environment.

About Us

We are a privately held employee-owned company offering superior compensation benefits professional development with ownership opportunities for excellent candidates. GSI is highly respected nationally and internationally for the quality of its professional environmental services and the technically advanced projects it has completed over its 39 years of operation.

GSI employs cross-disciplinary teams of environmental engineers and scientists including toxicologists geologists hydrogeologists ecologists chemists oceanographers and data scientists with seamless collaboration over both technical disciplines and offices. Headquartered in Houston Texas GSI operates offices in Texas (Austin and Houston) California (Irvine the San Francisco Bay Area and Folsom) Washington (Olympia) Montana (Missoula and Helena) North Carolina (Raleigh) and New York (Syracuse). Our talented staff of environmental professionals perform projects nationwide and internationally.

Location

Near one of our existing office locations. Remote arrangements will be considered for exceptionally qualified candidates.

Key Opportunities

  • Join a Thriving Firm: Be part of a privately-owned company renowned for its technical excellence and strong industry reputation. We are committed to measured purposeful growth that maintains the integrity of our unique culture.
  • Be a Leader and Owner: Take on a significant role in managing a mid-sized company with over 250 employees. Enjoy meaningful ownership and profit-sharing opportunities that recognize and reward your contributions.
  • Advance the Science: Lead and innovate in the fields of toxicology health sciences and risk assessment. Your expertise will drive advancements and make a tangible impact on our projects and the industry.

Key Responsibilities

  • Provide litigation support services on matters involving PFAS toxicology risk assessment and general causation. Develop and interpret conceptual site models and identify exposure pathways.
  • Lead and manage complex human health and ecological risk assessments for PFAS in soil water air sediment food and consumer products. Follow the emerging science and regulation of PFAS in biosolids and understand how these developments may affect clients and present business opportunities.
  • Communicate risk assessment findings to clients regulators and stakeholders through reports presentations and public meetings
  • Interpret and apply federal and state PFAS toxicology and risk assessment guidance (e.g. USEPA CalEPA state agencies).
  • Follow PFAS toxicology and exposure guidance developments from European and Australian agencies such as EFSA and understand how this guidance may affect US clients.
  • Support business development efforts by identifying new opportunities preparing proposals presenting webinars and similar presentations to professional and scientific organizations business groups and others; and use these venues to cultivate client relationships.
  • Provide technical oversight and quality assurance on deliverables
  • Mentor and train associate and mid-level staff in toxicology risk assessment methodologies regulatory frameworks and scientific best practices
  • Collaborate with technical staff across disciplines and offices


Qualifications

The successful candidate will have a strong track record of leadership and business development with the following qualifications and demonstrated experience:

  • Advanced degree in Toxicology Public Health Environmental Science or related field; PhD preferred.
  • Minimum of 15 years of professional experience in toxicological sciences and human health risk assessment with at least 5 years in a leadership or project management role;
  • DABT Professional certification or others (e.g. CIH etc.);
  • Demonstrated expertise with federal and state risk assessment guidance and regulatory frameworks (e.g. CERCLA RCRA TSCA DTSC CalEPA OEHHA);
  • Experienced in effective risk communication to clients regulators and public stakeholders through reports presentations public communication postings and meetings;
  • Proven ability to manage multiple projects lead cross-discipline technical teams and interface with clients and regulators;
  • Commitment to staying abreast of developments in the toxicology and risk assessment of PFAS and other emerging contaminants;
  • Litigation experience as a consulting and/or testifying expert.
  • Proven background in publication of peer-reviewed scientific publications on PFAS toxicology and/or risk assessment.
  • Ability to work across geographies with experts in different offices;
  • Strong mentoring professional development of staff and recruiting skills;
  • Excellent technical writing communication and analytical skills.

Why Join Us

  • Enjoy a competitive salary generous benefits and attractive year-end bonuses
  • Participate in company ownership and engage in the companys leadership and direction
  • Advance the science the firm and your career through conferences technical presentations and publications
  • Collaborate with leading experts and highly motivated staff in a fun fast-paced work environment

The base salary for this position will be determined by the candidates geographic location education relevant degree related experience and overall qualifications.



Required Experience:

Staff IC