Company lists · Data refreshed September 2026

Top 25 Toxicology consulting firms based in the United States

RevenueBase identified 477 toxicology consulting firms headquartered in the United States as of September 2026 and tracks 7,225 professional contacts across them, including 2,880 with verified work emails. Chicago is the largest hub.

This list covers toxicology consulting firms headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 29, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 29, 2026 86% judged on-target in blind review
477Companies
7,225Contacts tracked
2,880Verified emails
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The 25 largest toxicology consulting firms based in the United States

Ranked by team size
Top 25 of 477 toxicology consulting firms based in the United States, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to toxicology consulting firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Strong evidenceNashville, TN, United StatesHQ checked Sep 29, 2026501-1,000690 contacts →

Strong evidence

“Founded in 1990, Aegis Sciences Corporation is a forensic toxicology and healthcare laboratory that provides science-driven drug testing and consulting services based in…”

Source: RevenueBase Database · checked Sep 29, 2026
2Partial evidenceHorsham, PA, United StatesHQ checked Sep 29, 2026201-500411 contacts →

Partial evidence

“NMS Labs has been setting the standard for excellence in clinical toxicology and forensic testing-responding to the needs of healthcare providers, medical researchers, coroners…”

Source: RevenueBase Database · checked Sep 29, 2026
3Partial evidenceNorth Kingstown, RI, United StatesHQ checked Sep 29, 2026201-500304 contacts →

Partial evidence

“For over 25 years, Dominion Diagnostics has been advancing patient care through trusted diagnostics as a premier urine drug testing and toxicology laboratory.”

Source: RevenueBase Database · checked Sep 29, 2026
4Partial evidencePittsburgh, PA, United StatesHQ checked Sep 29, 2026201-500194 contacts →

Partial evidence

“RJ Lee Group provides comprehensive laboratory testing and scientific consulting services.”

Source: RevenueBase Database · checked Sep 29, 2026
5Indirect evidenceChicago, IL, United StatesHQ checked Sep 29, 202651-200188 contacts →

Indirect evidence

“IITRI was founded in 1936 as the research arm of the Illinois Institute of Technology (IIT).”

Source: RevenueBase Database · checked Sep 29, 2026
6Strong evidenceBoston, MA, United StatesHQ checked Sep 29, 202651-200159 contacts →

Strong evidence

“Gradient is an environmental and risk science consulting firm renowned for our specialties in Toxicology, Epidemiology, Risk Assessment, Product Safety, Contaminant Fate and…”

Source: RevenueBase Database · checked Sep 29, 2026
7Indirect evidenceWareham, MA, United StatesHQ checked Sep 29, 20261,001-5,000155 contacts →

Indirect evidence

“Smithers is a leading provider of environmental risk testing to the Agrochemical, Pharmaceutical, and Chemical industries.”

Source: RevenueBase Database · checked Sep 29, 2026
8Indirect evidenceElmhurst, IL, United StatesHQ checked Sep 29, 202651-200140 contacts →

Indirect evidence

“Since the passage of original environmental legislation nearly four decades ago, both private and public industry have turned to Mostardi Platt for guidance in complying with air…”

Source: RevenueBase Database · checked Sep 29, 2026
9Partial evidenceHorsham, PA, United StatesHQ checked Sep 29, 202651-200132 contacts →

Partial evidence

“Drugscan is a national toxicology and infectious disease testing laboratory that partners with organizations and providers to provide the critical testing they need for healthier…”

Source: RevenueBase Database · checked Sep 29, 2026
10Indirect evidenceHercules, CA, United StatesHQ checked Sep 29, 202651-200120 contacts →

Indirect evidence

“Pacific BioLabs is the leading West Coast provider of GMP/GLP laboratory testing services supporting Medical Device, Pharmaceutical, and Biotechnology industries.”

Source: RevenueBase Database · checked Sep 29, 2026
11Partial evidenceMorrisville, NC, United StatesHQ checked Sep 29, 202651-200111 contacts →

Partial evidence

“The EI Group, Inc.(EI) is an environmental, health and safety consulting firm headquartered in Research Triangle Park, North Carolina, with branch offices strategically located…”

Source: RevenueBase Database · checked Sep 29, 2026
12Indirect evidenceOrange, CA, United StatesHQ checked Sep 29, 202651-20097 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 29, 2026
13Indirect evidenceLakewood, CO, United StatesHQ checked Sep 29, 202651-20088 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 29, 2026
14Indirect evidenceGainesville, FL, United StatesHQ checked Sep 29, 202611-5087 contacts →

Indirect evidence

“Water and Air Research, Inc.”

Source: RevenueBase Database · checked Sep 29, 2026
15Indirect evidenceValley Forge, PA, United StatesHQ checked Sep 29, 202651-20083 contacts →

Indirect evidence

“Environmental Standards is now part of Onterris.”

Source: RevenueBase Database · checked Sep 29, 2026
16Partial evidenceSan Diego, CA, United StatesHQ checked Sep 29, 202611-5074 contacts →

Partial evidence

“Occupational Services, Incorporated is a San Diego-based professional consulting firm providing services in the areas of environmental compliance, occupational health and safety…”

Source: RevenueBase Database · checked Sep 29, 2026
17Strong evidenceMansfield, MA, United StatesHQ checked Sep 29, 202651-20063 contacts →

Strong evidence

“Jordi Labs, an RQM+ company, delivers regulator-credible testing, toxicology, and scientific consulting that de-risk submissions and get safe MedTech products to patients faster.”

Source: RevenueBase Database · checked Sep 29, 2026
18Indirect evidenceGainesville, VA, United StatesHQ checked Sep 29, 202611-5056 contacts →

Indirect evidence

“Founded in toXcel is committed to promoting and improving the safety, health, and well-being of people everywhere.”

Source: RevenueBase Database · checked Sep 29, 2026
19Indirect evidenceChicago, IL, United StatesHQ checked Sep 29, 202611-5052 contacts →

Indirect evidence

“Carnow, Conibear & Assoc, Ltd.(Carnow Conibear), a minority-owned, woman-owned and veteran-owned business, was established in 1975.”

Source: RevenueBase Database · checked Sep 29, 2026
20Partial evidenceSunnyvale, CA, United StatesHQ checked Sep 29, 202651-20050 contacts →

Partial evidence

“SafeBridge is the premier resource for high-level safety and health consulting to the pharmaceutical, biotechnology, and specialty chemicals industries.”

Source: RevenueBase Database · checked Sep 29, 2026
21Partial evidenceHouston, TX, United StatesHQ checked Sep 29, 202611-5046 contacts →

Partial evidence

“International Safety Systems, Inc.(ISS) is a consulting company providing cost effective and high quality industrial hygiene and safety services to 35+ countries from its offices…”

Source: RevenueBase Database · checked Sep 29, 2026
22Indirect evidenceAtlanta, GA, United StatesHQ checked Sep 29, 202651-20046 contacts →

Indirect evidence

“EWH has earned credibility among its peers on both sides of the litigation bar and with the judiciary officers before whom its lawyers have appeared.”

Source: RevenueBase Database · checked Sep 29, 2026
23Partial evidenceStilwell, KS, United StatesHQ checked Sep 29, 202651-20045 contacts →

Partial evidence

“Attentive Science is an FDA inspected, accredited premier global leader, excelling in GLP and nonGLP in-vivo pharmacokinetics, toxicology, and safety pharmacology services.”

Source: RevenueBase Database · checked Sep 29, 2026
24Partial evidenceGarden City Park, United StatesHQ checked Sep 29, 202651-20044 contacts →

Partial evidence

“Truetox Laboratories, LLC, is a revolutionary toxicology laboratory licensed in all 50 states and providing state-of-the-art employee, clinical, and forensic laboratory services.”

Source: RevenueBase Database · checked Sep 29, 2026
25Partial evidenceBorger, TX, United StatesHQ checked Sep 29, 202651-20043 contacts →

Partial evidence

“Provenance Consulting is now a part of Trinity Consultants.”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 25 of 477 toxicology consulting firms based in the United States

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Toxicology consulting firms based in the United States at a glance

As of Sep 29, 2026
39.9%Verified-email coverage
15.1Average contacts per company
1-10Median size (employees)
1.9%Largest-city concentration · Chicago
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
282
11-50
131
51-200
49
201-500
8
501-1,000
2
1,001-5,000
2
5,001-10,000
1

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 477 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among toxicology consulting firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “toxicology consulting firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names toxicology consulting firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among toxicology consulting firms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 2,880 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 29, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names toxicology consulting firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many toxicology consulting firms are there based in the United States?

RevenueBase identified 477 toxicology consulting firms headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Aegis Sciences Corporation, headquartered in Nashville, tops this list with the largest team on record.

Which city has the most toxicology consulting firms?

Chicago leads with 9 headquartered companies, followed by San Diego (7) and Washington (7).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 2,880 verified decision-maker contacts tracked across these 477 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 29, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.