Critical Path Services, LLC

Main Location:
3070 McCann Farm Drive
Suite 112
Garnet Valley, PA 19060
PHONE: 610.558.3001
FAX: 610.558.6025

Research Triangle Park, NC:
68 T.W. Alexander Drive
Alexander Business Suites
Research Triangle Park, NC 27709

Carrollton, TX:
1415 Halsey Way
Suite 304
Carrollton, TX 75007
Phone # 972.446.6611
Fax 972.446.6622

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CPS Environmental Fate Modeler Participates in EPA Workshop on National Ambient Air Quality Standards

On March 4, 2014, Dr. Jean-Jacques Dubois, environmental fate scientist and modeler at Critical Path Services, participated in the US EPA's three day Workshop in Support of the Review of the Secondary National Ambient Air Quality Standards (NAAQS) for oxides of nitrogen and sulfur. Dr. Dubois was invited as a panelist because of his expertise on the role of oxides of sulfur in mercury methylation in the environment, as well as his experience in comprehensive scientific review and innovative literature search methods.

The Workshop was the first step in the EPA review of NAAQS for the pollutants in question. Among regulations worldwide, the U.S. Clean Air Act is likely the single piece of legislation with the largest influence on atmospheric pollutants. The EPA sets NAAQS for six principal pollutants that are derived from numerous sources and are considered harmful to public health and the environment (the six pollutants are: ozone, particulate matter, carbon monoxide, sulfur oxides, nitrogen oxides, and lead). The Clean Air Act mandates that each of the six NAAQS be reviewed every five years, and each step of the process is conducted with close review by a committee of external experts, as well as input from all stakeholders.

The basis of a NAAQS revision is the Integrated Science Assessment, a comprehensive review, synthesis, and evaluation of the most policy-relevant science, where EPA identifies and assesses peer-reviewed information published up to the time of the standards review. All subsequent risk and policy assessment, followed by rulemaking, refers to this document. The Workshop provided a platform for subject matter experts in the general public to inform EPA of relevant data that has come to light since the last review of NAAQS for oxides of nitrogen and sulfur.

Dr. Dubois was one of three panelists tasked with discussing new developments in the influence of oxides of sulfur on mercury methylation. While the largest effect of oxides of sulfur on ecosystems is acidification, mercury methylation has attracted attention because of widespread concern about mercury found in fish caught in American lakes and rivers. As of 2010, there were 3,710 advisories for mercury, and 25 states had statewide advisories for mercury in freshwater lakes and/or rivers. 16.4 million lake acres and 1.14 million river miles were under advisory nationwide, which corresponds to 39% of the total lake acreage and 32% of total river miles. Mercury becomes a serious environmental neurotoxin when it is methylated by the action of sulfur-reducing aquatic microorganisms, and in the methylated form, starts accumulating in gradually higher concentrations at higher levels in the food chain. Several factors are known to influence the rate at which sulfur-reducing microorganisms produce methylmercury, including dissolved organic acids and pH, and it also has been established that when mercury is present, more atmospheric deposition of SO2 results in greater concentrations of methylmercury in sediment, in water, and in fish at the top of the aquatic food chain. However, an exact quantification of the influence of the various factors involved besides mercury and oxides of sulfur is still missing. The production of methylmercury in freshwater bodies increases when deposition of oxides of sulfur increases, and decreases when deposition decreases, but how much methylmercury is produced in various locations around the country cannot be reliably predicted.  We do know, however, that where methylmercury is present in excessive amounts in fish, both mercury and oxides of sulfur have to excessive in the environment.

For more information on NAAQS or to schedule a meeting with one of our experts, please contact us at


Update on the Implementation of GHS in North America: U.S., Canada, and Mexico

As GHS is implemented across the globe, it is important to remember two things:  first, not all countries are at the same point in the implementation process and second, not all countries are implementing the same version of GHS.  Even those countries who do implement the same version are able to customize GHS to fit their individual needs and preferences. 

Within North America, the United States, Canada and Mexico are all at different places in their implementation of GHS.  The U.S. published the revised Hazard Communication Standard in 2012 with implementation to be completed by June 1, 2015.  Canada’s regulations to address GHS are currently in draft form and are expected to be published by June 2015, with implementation expected to begin in July 2015.  And finally, Mexico’s GHS standard (NMX-R-SCFI-2011) was published in June 2011, but the standard is  currently not mandatory.

There are some similarities within GHS in North America.  For example, the U.S., Canada and Mexico are all implementing UN GHS Revision 3.  Canada wants to synchronize implementation with the U.S. to the greatest extent possible and that has resulted in Canada and the U.S. being alike in their approach to the implementation.  Both countries decided against the inclusion of the same building blocks:  Acute Toxicity, Category 5; Skin Corrosion/Irritation, Category 3; Aspiration Hazard, Category 2; Hazardous to the Aquatic Environment, Acute and Chronic – all categories.  Additionally, Canada is expected to include the same additional hazards not documented in the Purple Book as the U.S. did.  These include combustible dust, simple asphyxiants and pyrophoric gases.  Mexico’s approach was to implement all of the Revision 3 hazard classes and categories in the Purple Book, as is.

Critical Path Services (CPS) and knoell will continue to follow the ever-changing scope of GHS both in North America and worldwide so that we will be able to continue providing our clients with solutions to help them meet their regulatory needs.


CPS Attends AAPS Crystal City-V Conference on the FDA Draft Guidance on Bioanalytical Methods Validation

Dr. Larry Mallis, CPS Laboratory Director, attended a 3-day workshop of the American Association of Pharmaceutical Scientists (AAPS) focused on FDA’s recently revised draft guidance on quantitative bioanalytical methods validation, and the implementation of that guidance. The workshop was held to provide a platform for open discussion between industry and the FDA around these topics.

Originally published in 2001, the guidance was revised to demonstrate advances in methods for bioanalytical validation. Since that time, AAPS, in conjunction with the FDA, has held multiple workshops and events that have informed changes made in the new draft guidance. The draft guidance includes new sections, including discussions of endogenous compounds, incurred sample reanalysis, biomarker assays, use of diagnostic kits and new technologies, system suitability, and report formats for tabular data listings. Other text has been updated, such as the sections on chromatography and ligand-binding assays.

One of the significant changes to the guidance is the percent of incurred samples to be reanalyzed (ISR).  Previous confusion around this point has led the agency to suggest that a flat 7% of incurred samples be chosen for reanalysis.  This was hotly debated due largely in part to the fact that the EMA guidance document (released in 2012) indicated 10% ISR up to 1000 samples, and 5% for sample sets greater than 5%.

AAPS will produce white papers discussing consensus outcomes of the discussions during the presentations related to each section of the new draft guidance.  Once these white papers are made available, CPS will provide them as links on our website.

CPS is committed to staying informed of changes to this and other important guidance relating to methods validation. Our full-service, GLP-compliant laboratory can meet trace level detection limits, work within complicated matrices, and achieve quick turn-around times.


The Need for Data: Three Perspectives on TSCA Reform

At the recent Chemical Watch Summit, attendees had the opportunity to listen to numerous perspectives on TSCA reform, a topic that has attracted significant attention in recent months. Of particular note were presentations from the federal government, a prominent NGO, and a leading manufacturer of downstream consumer products. One of the underlying themes of the discussion was the need for good data on more chemicals.

Richard Denison of the Environmental Defense Fund provided background on TSCA, and in so doing emphasized the need for reform. He began with a thorough overview of changes that have occurred since TSCA was passed in 1976. In short, global chemical production has increased dramatically (25 fold) from 1970 to 2010. We now have a better understanding of how to screen and assess chemicals, yet the regulatory framework for evaluating them lags behind. Under TSCA, EPA has the responsibility to assess chemicals, although they lack the authority to obtain the necessary information in an efficient way. As a result, EPA has only regulated five of the over 60,000 chemicals that were grandfathered in under TSCA, and the Agency has required testing on less than 300. There is a general lack of use and exposure data, and even hazard data are very limited in their availability. Under TSCA, no data generally means no action, and there is a need for a new legislation that enacts a regulatory framework moving us “from assuming safety if there is no evidence of harm, to requiring evidence of safety before entering the market.” To make this paradigm shift, good data on numerous chemicals are needed. 

Jeff Morris of the US EPA spoke about the Agency’s increased attention to existing chemicals, but also noted that there are many chemicals for which we have very little data. Critical to EPA’s Existing Chemicals Program is development of 21st century approaches for screening and prioritizing chemicals. EPA is also making an effort to obtain data through collaboration with international governments, such as Canada, on specific groups of chemicals such as nanomaterials. When asked whether EPA plans to approach the European Chemical Agency about a comprehensive data sharing plan, their response was that collaboration is best done on a case-by-case basis.

Julie Froelicher of Proctor and Gamble represented the downstream industry perspective. She described the pressure that industry  receives from numerous stakeholders (e.g., consumers, retailers, states, federal government) for access to data on chemicals. While industry understands these requests, they must be careful in what they disclose. Retailers such as Walmart and Target are developing sustainable product standards and even offer incentive programs for disclosing ingredients. However, transmittal of otherwise proprietary information can create a conflict for industry because some of these large retailers offer their own competing brands. Yet processing companies such as Proctor and Gamble recognize that they are in a unique position to provide use and exposure information to EPA, and this information may not be available to the manufacturers and importers who have been traditionally responsible for providing data. To this end, the Consumer Specialty Products Association (CSPA) is designing a project with EPA in which companies will report use information for select TSCA Work Plan chemicals, and EPA will evaluate this information for further prioritization of remaining Work Plan chemicals.

Critical Path Services is committed to staying abreast of regulatory changes in the US and worldwide. Follow our blog for updates on TSCA and other key US regulations.


Pesticide Registration in the United States

Pesticides can be harmful to humans and pests if they are not used according to label instructions.  The information given on the label is the result of extensive testing and a lengthy registration process.  In the United States, the label acts as the license for a company to sell that product.

The Federal, Insecticide, Fungicide, Rodenticide, Act (FIFRA) is the primary federal law that governs how the EPA oversees pesticide use in the US.  FIFRA identifies a pesticide in Section 2 as, “Any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest; any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant; and any nitrogen stabilizer.”

To register a pesticide, an application form must be completed and fees according to PRIA (Pesticide Registration Improvement Renewal Act) must be paid.  Next, a registration package must be assembled that consists of studies covering the following data requirements:  physical chemistry, mammalian and eco- toxicology, analytical methods, residue, and environmental fate.  The quality of study data must be good and follow GLP (Good Laboratory Practices) where necessary.  Reports must follow PR Notice 2011-3, which describes both the recommended and required procedures for electronic and paper FIFIRA submissions.

The registration package also contains information on the pesticide use, including the application concentration and rate.  It provides information on how the pesticide will be used, where it can be applied, and the types of personnel protective equipment that are required. This information also appears on the pesticide label.  

Important to note is that pesticide registrations in the US are use-specific. This means that companies may need to submit multiple registrations for the same product if it has multiple uses. However, the same data can often be used to support multiple registrations for different uses in the US, or for registrations outside of the US. Critical Path Services has expertise in identifying registration requirements and the data needed to fulfill these requirements in regulatory jurisdictions around the globe. As a knoell company, we specialize in worldwide registration of agrochemicals.

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