TSCA Section ,	terniinatioii for Microbial Commercial Activity Notice (MCAN) J-

18-0028 to 0030

Number: J-18-0028 to 0030

TSCA Section 5(a)(3) Determination: The microorganisms are not likely to present an
unreasonable risk (5(a)(3)(C))

Chemical Name:

Generic: Saccharomyces cerevisiae modified

Conditions of Use (intended, known, or reasonably foreseen)1:

Intended use(s) (generic): Ethanol production.

Known conditions of use: None.

Reasonably foreseen conditions of use(s): Applying such factors as described in footnote 1, EPA
evaluated whether there are reasonably foreseen conditions of use and found none.

Summary: The microorganisms are not likely to present an unreasonable risk based on low
human health hazard and low environmental hazard associated with the recipient microorganism
and introduced genetic material. S. cerevisiae is not pathogenic to humans or animals and has an
extensive history of safe use in food processing. The introduced genetic modifications pose low
concern for health and environmental hazard and do not include antibiotic resistance markers.

Human Health Hazard2: Human health hazard is relevant to whether a new microorganism is
likely to present an unreasonable risk because the significance of the risk is dependent upon both
the hazard (e.g., pathogenicity/toxicity) of the microorganism and the extent of exposure to the
microorganism. EPA estimated the human health hazard of these microorganisms based on data
for the recipient parental strain as well as the genetic modifications. S. cerevisiae, also known
as baker's yeast, has a long history of safe use in baking, winemaking, and brewing. There is
low concern for human health hazard for the microorganisms based on the recipient strain
not being a human pathogen and the introduced genetic material encoding common enzymes

1	Under TSCA § 3(4), the term "conditions of use" means "the circumstances, as determined by the Administrator,
under which a chemical substance (including an intergeneric microorganism) is intended, known, or reasonably
foreseen to be manufactured, processed, distributed in commerce, used, or disposed of." In general, EPA considers
the intended conditions of use of a new chemical substance to be those identified in the section 5(a) notification.
Known conditions of use include activities within the United States that result from manufacture that is exempt from
MCAN submission requirements. Reasonably foreseen conditions of use are future circumstances, distinct from
known or intended conditions of use, under which the Administrator expects the MCAN microorganism to be
manufactured, processed, distributed, used, or disposed of. The identification of "reasonably foreseen" conditions of
use will necessarily be a case-by-case determination and will be highly fact-specific. Reasonably foreseen
conditions of use will not be based on hypothetical or conjecture. Accordingly, EPA will apply its professional
judgment, experience, and discretion when considering such factors as evidence of current use of the new
microorganism outside the United States, evidence that the MCAN microorganism is sufficiently likely to be used
for the same purposes as existing microorganisms that are similar, and conditions of use identified in an initial
MCAN submission that the submitter omits in a revised MCAN. The sources EPA uses to identify reasonably
foreseen conditions of use include searches of internal confidential EPA MCAN databases (containing use
information on analogous microorganisms), other U.S. government public sources, and Internet searches.

2	A microorganism is considered to have low human health hazard if it is not known to be a frank human pathogen
that causes disease in healthy adults, and/or animal studies have demonstrated a lack of pathogenicity or toxicity; a
microorganism is considered to have high human health hazard if there is evidence of adverse effects in humans or
conclusive evidence of severe effects in animal studies. In the absence of animal data on a microorganism, EPA may
use other data or information obtained through literature searches.


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TSCA Section ,	terniinatioii for Microbial Commercial Activity Notice (MCAN) J-

18-0028 to 0030

found in many microorganisms.

Environmental Hazard3: Environmental hazard is relevant to whether a new microorganism is
likely to present unreasonable risks because the significance of the risk is dependent upon both
the hazard (e.g., pathogenicity/toxicity) of the microorganism and the extent of exposure to the
microorganism. EPA estimated the environmental hazard of these microorganisms based on
data for the recipient parental strain as well as information on the genetic modifications.
There is low concern for environmental hazard for the microorganisms based on the
recipient strain not being an animal or plant pathogen and the introduced genetic material
encoding for common enzymes found in many microorganisms.

Exposure and Risk Characterization: The exposure to a new microorganism is potentially
relevant to whether a new microorganism is likely to present unreasonable risks because the
significance of the risk is dependent upon both the hazard (e.g., pathogenicity/toxicity) of the
microorganism and the nature and extent of exposure to the substance. However, in this case
EPA did not estimate the exposure because EPA determined that the microorganism presents
both low human health hazard and low environmental hazard. Due to low hazard, EPA believes
that these microorganisms would be not likely to present an unreasonable risk even if exposures
were high. Therefore, EPA concludes that the new microorganisms are not likely to present
unreasonable risk under the conditions of use.

Potentially Exposed or Susceptible Subpopulation(s): Workers are potentially exposed.

Given the low hazard of these microorganisms, EPA finds that these microorganisms are not
likely to present unreasonable risk to workers. Risks to the general population were not assessed
due to low hazard. No consumer use was identified, so risks to consumers were not assessed.

9/14/18		/s/	

Date:	Jeffery T. Morris, Director

Office of Pollution Prevention and Toxics

3 A microorganism is considered to be of low ecological hazard if it is not known to be an animal or plant pathogen,
and the genetic modifications do not impart pathogenic or toxigenic traits, and the introduced genetic material does
not provide a selective growth advantage in outcompeting indigenous microbial communities in the environment.


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