CTEH

What CTEH does

CTEH (Center for Toxicology and Environmental Health), founded in 1997 and headquartered in North Little Rock, Arkansas, is an environmental and public health consulting firm specializing in emergency response, toxicology, industrial hygiene, and environmental health services. The firm operates a 24/7 emergency response hotline and deploys field teams to incidents involving chemical releases, industrial accidents, and environmental contamination, providing air monitoring, exposure assessment, and real-time data interpretation. Its offerings also include stack testing and source emissions testing, leak detection and fugitive emissions management, contaminated land remediation, permitting and compliance support, water consulting, community resiliency, and laboratory services. CTEH serves industrial and manufacturing clients, government agencies (including EPA, OSHA, and state entities), and legal sector clients requiring defensible environmental data for litigation and regulatory proceedings.

The firm was acquired by Montrose Environmental Group in 2020, and in May 2026 the parent rebranded to Onterris (NYSE: ONT), unifying CTEH with sister brands ECT2, Enthalpy Analytical, and Epic Environmental under a single global identity operating in the U.S., Canada, and Australia. The combined platform spans approximately 101-250 CTEH employees plus a broader parent headcount, with revenue derived from project-based professional services contracts quoted per engagement rather than standardized pricing tiers. Marketing and distribution are direct enterprise sales-led, supported by thought leadership content (e.g., the Onterris Outlook Report, Federal Methane Rules commentary, CCL 6 perspective) and a corporate website segmented by sector and solution. In March 2026, the firm formalized partnerships with KnightHawk Engineering and Ocean Ridge Litigation Support to expand its petrochemical forensics and incident reconstruction capabilities.

Name

CTEH

Legal name

Onterris, Inc.

Website

https://cteh.com

Company type

Public

Founded year

1997

Operating status

Operating

Headcount range

251–500 employees

Short description

CTEH, now operating as Onterris, is a 1997-founded environmental and public health consulting firm providing 24/7 emergency response, toxicology, industrial hygiene, and emissions testing services to industrial, government, and legal sector clients across the U.S., Canada, and Australia.

Ownership category

akta.pro rank

Product category

Environmental Consulting and Testing Services

NAICS

Environmental Consulting Services (541620), Remediation Services (56291), Remediation and Other Waste Management Services (5629)

SIC

Services-Commercial Physical & Biological Research (8731), Services-Management Consulting Services (8742), Hazardous Waste Management (4955)

akta.pro primary industry

Site Assessment & Remediation (Phase I/II, Cleanup Oversight) (BPAHAJAC)

akta.pro secondary industries

Hazardous Materials (HAZMAT) Spill Response & Decontamination (BPABANAH), Waste & Hazardous Materials Management (incl. HazMat) (BPAHAJAK), Radiological & Hazardous Materials Monitoring (Radiation, Asbestos, Lead) (EUAHACAJ)

Keywords

• Environmental consulting services
• Emergency response services
• Toxicology consulting
• Industrial hygiene services
• Environmental testing and analysis

Headquarters

HQ city

North Little Rock

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Infrastructure, Marketing or Sales

Revenue model

1. Emergency Response Services: Rapid and scalable environmental and public health response during incidents involving chemical releases, industrial accidents, and environmental contamination. Provides air monitoring, exposure assessment, toxicology analysis, and real-time data interpretation
2. Toxicology and Environmental Health Consulting: Consulting services across toxicology consulting, industrial hygiene, environmental health, and regulatory compliance for industrial, governmental, and legal sectors
3. Environmental Consulting and Remediation: Support for environmental due diligence, risk evaluation, regulatory compliance, remediation planning, and long-term operational goals

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels5 records

Core offering

CTEH (now Onterris) is a management, technology, and science-based consulting firm providing rapid and scalable environmental and public health response during incidents involving chemical releases, industrial accidents, and environmental contamination. Core offerings include 24/7 emergency response with air monitoring and sampling, toxicology and exposure assessment, EPA-compliant stack and source emissions testing, leak detection and fugitive emissions management, contaminated land remediation, permitting and compliance, and laboratory analytical services. Services are delivered as professional consulting engagements to industrial, governmental, and legal sector clients across the U.S., Canada, and Australia.

Product overview

Onterris (formerly CTEH - Center for Toxicology and Environmental Health) is a global environmental solutions company that was acquired by Montrose Environmental Group in 2020 and rebranded to Onterris in May 2026. The company operates as a services firm rather than a software platform, offering a portfolio of interconnected environmental consulting and testing services. The core offerings include Emergency Response (rapid incident response for chemical releases and environmental emergencies), Testing & Analysis (EPA-compliant stack testing, leak detection, laboratory services), and specialized consulting services in Health/Safety/Chemistry, Water Consulting, Permitting & Compliance, Contaminated Land Remediation, Natural Resources, and Community Resiliency. These solutions serve clients across industrial, governmental, and legal sectors, providing defensible data for regulatory and legal proceedings while supporting long-term environmental compliance.

Differentiator

Problem solved

Functional benefit

Products and services

• Emergency Response Rapid and scalable environmental and public health response during incidents involving chemical releases, industrial accidents, and environmental contamination, including air monitoring, exposure assessment, toxicology analysis, and real-time data interpretation. Available 24/7 via emergency hotline.
• Stack Testing and Source Emissions Testing Accurate, EPA-compliant stack testing and source emissions monitoring and analysis services for industrial facilities.
• Leak Detection and Fugitive Emissions Management Monitoring and detection services to manage fugitive emissions in complex industrial facilities such as refineries and chemical plants.
• Contaminated Land & Remediation Environmental consulting services for assessment of contaminated land and planning of remediation activities.
• Permitting & Compliance Regulatory compliance support and permitting services for environmental projects, including interaction with EPA, OSHA, state agencies, and ACGIH-aligned action levels.
• Planning, Preparedness, Response & Recovery Comprehensive emergency management services including planning, preparedness training, incident response, and recovery support for environmental and public health challenges.
• Health, Safety & Chemistry Industrial hygiene and occupational health services including toxicology consulting, exposure assessment, and chemical safety assessments.
• Testing & Analysis Laboratory analysis and environmental testing services for various contaminants and samples using validated analytical methods.
• Water Consulting, Testing & Treatment Water quality consulting, testing, and treatment solutions for industrial and environmental applications.
• Community Resiliency Support services helping communities build resilience and recover from environmental incidents, including climate-related events.
• Natural Resources Assessment and management services for natural resource protection and sustainability.
• Laboratory Services Advanced laboratory analysis and support services for environmental samples and testing.
• Treatment Technologies Environmental treatment technology solutions, referenced under the Onterris solutions portfolio.

Quantifiable outcome

• EPA consistently approves data processes and interpretations
• +1 more outcomes

Named customers3 records

Segments4 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Two partnerships are on record, tiered minor.

• KnightHawk EngineeringminorImplementation/ SI/ Consulting Partner · 17 March 2026ATA Associates formalized a partnership with KnightHawk Engineering as part of strategic expansion of petrochemical forensics capabilities. KnightHawk provides multidisciplinary expertise in mechanical engineering for complex industrial incident investigations.
• Ocean Ridge Litigation SupportminorImplementation/ SI/ Consulting Partner · 17 March 2026ATA Associates formalized a partnership with Ocean Ridge Litigation Support as part of strategic expansion of petrochemical forensics capabilities. Ocean Ridge provides incident reconstruction and root-cause analysis expertise.

Scale indicators3 records

Recent moves6 records

Expansion highlights5 records

Market position

Strengths5 records

Weaknesses1 record

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/CTEHLLC
• YouTubeyoutube.com/@onterris
• LinkedInlinkedin.com/company/onterris
• Facebookfacebook.com/CTEHLLC

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Subsidiaries4 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about CTEH