Controlling toxic substances 2012

Controlling Toxic Substances

Regulation of toxic substances requires rule makers to cope with the problem of scientific uncertainty

How is a regulatory agency to determine whether a chemical is “safe”?

Table 8.03

How the risk is determined?

1. Hazard Identification, aims to determine the qualitative nature of the potential adverse consequences of the contaminant (chemical, radiation, noise, etc.) and the strength of the evidence it can have that effect. This is done, for chemical hazards, by drawing from the results of the sciences of toxicology and epidemiology. For other kinds of hazard, engineering or other disciplines are involved.

2. Dose-Response Analysis, is determining the relationship between dose and the probability or the incidence of effect (dose-response assessment). The complexity of this step in many contexts derives mainly from the need to extrapolate results from experimental animals (e.g. mouse, rat) to humans, and/or from high to lower doses. In addition, the differences between individuals due to genetics or other factors mean that the hazard may be higher for particular groups, called susceptible populations. (see figures)

3. Exposure Assessment, aims to determine the amount of a contaminant (dose) that individuals and populations will receive. This is done by examining the results of the discipline of exposure assessment. As different location, lifestyles and other factors likely influence the amount of contaminant that is received, a range or distribution of possible values is generated in this step. Particular care is taken to determine the exposure of the susceptible population(s).4. Risk Characterization, the results of the first three steps above are then combined to produce an estimate of risk (e.g. magnitude of the public health problem). Because of the different susceptibilities and exposures, this risk will vary within a population.

Figure 8.18

Figure 8.17

How the risk is determined?

1. Hazard Identification, aims to determine the qualitative nature of the potential adverse consequences of the contaminant (chemical, radiation, noise, etc.) and the strength of the evidence it can have that effect. This is done, for chemical hazards, by drawing from the results of the sciences of toxicology and epidemiology. For other kinds of hazard, engineering or other disciplines are involved.

2. Dose-Response Analysis, is determining the relationship between dose and the probability or the incidence of effect (dose-response assessment). The complexity of this step in many contexts derives mainly from the need to extrapolate results from experimental animals (e.g. mouse, rat) to humans, and/or from high to lower doses. In addition, the differences between individuals due to genetics or other factors mean that the hazard may be higher for particular groups, called susceptible populations. (see figures)

3. Exposure Assessment, aims to determine the amount of a contaminant (dose) that individuals and populations will receive. This is done by examining the results of the discipline of exposure assessment. As different location, lifestyles and other factors likely influence the amount of contaminant that is received, a range or distribution of possible values is generated in this step. Particular care is taken to determine the exposure of the susceptible population(s).4. Risk Characterization, the results of the first three steps above are then combined to produce an estimate of risk (e.g. magnitude of the public health problem). Because of the different susceptibilities and exposures, this risk will vary within a population.

Risk perception is an important aspect of risk acceptance. Our perception does not usually coincide well with reality.

•People tend to downplay certain risks and emphasize others that suit their own agendas•Most people do not think in terms of (or understand) probabilities•Influenced by own experience•Exaggerated view of own abilities•Media bias•Irrational fear/distrust for unfamiliar technologies or processes

Scientific Uncertainty

•problem inherent to regulating toxic and hazardous substances

•while you may be able to demonstrate an effect at a particular dosage with a model animal in the lab, or show a trend for people who have been exposed, it is more difficult to decide on a dosage or exposure level with no effect on humans or the environment

•How do you decide what rate of exposure is an acceptable risk? Is this the same for the whole population?

•In the US EPA and OSHA use risk assessment to determine the "acceptable risk”

Scientific Uncertainty

•Ethyl Corporation v. United States EPA (1977)•"Undoubtedly certainty is a scientific ideal - to the extent that science can even be certain of its truth. But certainty in the complexities of environmental medicine may be achievable only after the fact, when scientists have the opportunity for leisurely and isolated scrutiny of an entire mechanism…. Awaiting certainty will often allow for only reactive, not preventative regulation. Petitioners suggest that anything less than certainty, that any speculation, is irresponsible. But when statutes seek to avoid environmental catastrophe, can preventative, albeit uncertain decisions legitimately be so labeled?”

•In Ethyl Corp. v. EPA (1976), the U.S. Court of Appeals for the District of Columbia Circuit held that the EPA could regulate a substance even though it could not be proved that the substance was harmful. The court said the EPA could proceed if it could show a significant risk of harm. The ruling in this case has been incorporated in the Clean Air Act.

Precautionary Principlesays that when an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if the risks are not fully understood. By this principle, for example, we shouldn't mass-market new chemicals, new cars or new children's toys until we're sure they are safe. These are four widely accepted tenets of precautionary action:

1. People have a duty to take steps to prevent harm. If you suspect something bad might happen, you have an obligation to try to stop it.

2. The burden of proof of carelessness of a new technology, process, activity, or chemical lies with the proponents, not with the general public.

3. Before using a new technology, process, or chemical, or starting a new activity, people have an obligation to examine a full range of alternatives, including the alternative of not using it.

4. Decisions using the precautionary principle must be open and democratic and must include the affected parties.

An important element of the precautionary principle is that its most meaningful applications pertain to those that are potentially irreversible.

European Union has adopted this precautionary principle as the basis of its environmental policy.

In the U.S. historically there has been opposition to doing this. Why might this be? Do you agree?

The Toxic Substances Control Act (TSCA) is a United States law, passed by the United States Congress in 1976, that regulates the introduction of new or already existing chemicals. It grandfathered most existing chemicals, in contrast to the Registration, Evaluation and Authorization of Chemicals (REACH) legislation of the European Union.

TSCA specifically regulates polychlorinated biphenyl (PCB) products.

Contrary to what the name implies, TSCA does not separate chemicals into categories of "toxic" and "non-toxic". Rather it prohibits the manufacture or importation of chemicals that are not on the TSCA Inventory (or subject to one of many exemptions). Chemicals that are listed on the TSCA inventory are referred to as "existing chemicals". Chemicals not listed are referred to "new chemicals". Generally, manufacturers must submit premanufacturing notification to the U.S. Environmental Protection Agency (EPA) prior to manufacturing (or importing) new chemicals for commercial purposes. There are notable exceptions, including one for research and development, and for substances regulated under other statutes such as the Federal Food, Drug, and Cosmetics Act and the Federal Insecticide, Fungicide, and Rodenticide Act.

New chemicals notifications are reviewed by the Agency and if the Agency finds an "unreasonable risk to human health or the environment", may regulate the substance in a variety of ways, from limiting uses or production volume to an outright ban.

TSCA: Toxic Substances

Control Act 1976

OPPT: Office of Pollution

Prevention and Toxics

Treatment of Old Chemicals

Treatment of New Chemicals

OPPT: Office of Pollution Prevention and Toxics

in charge of implementation of the 3 major policies of the TSCA

1) Data on environmental effects of chemicals must be

developed by industry

2) Government must have adequate authority to prevent unreasonable risk of injury to

health or the environment

3) Government authority must be exercised so as to not "impede unduly or create unnecessary barriers to

technology while fullfilling the primary purpose of the act"

Treatment of Old Chemicals

Chemical Substance Inventory

up to 50 chemicals can be on the "high priority" list for a given year

In 1986, 18,000 chemicals on its inventory with no information on

toxic effects for 79%; less than one fifth have been tested for short-term effects, and less than one-

tenth for long term, reproductive or mutagenic effects

Currently, >84,000 chemicals listed

Treatment of New Chemicals

Premanufacturing Notice (PMN) - "section 5 notice”

90 day notice in advance of manufacture or importation of a new chemical for sale or use

in commerce

detailed description of use and distribution of the chemical

including disposal; also requires a review of all available test data with

respect to human health and environmental effects

considered weak legislation since it does not call for testing, but rather just

reporting testing data that are available

within 5 days of receipt EPA must publish the PMN in the

federal register

If there are to be restrictions on the use of the chemical the

EPA is must act to limit use within 45 days

1995 study of PMNs showed that 67% lacked toxicity data

and 85% had only limited data

A NEW APPROACH TO CHEMICAL REGULATION (TSCA Reform)

The Obama administration’s Essential Principles for Reform of Chemicals Management Legislation

are intended to aid Congress during the legislative process. The principles, listed below, present the

administration’s goals for legislation that will give EPA the ability to target chemicals of concern and

promptly assess and regulate new and existing chemicals in commerce:

• Chemicals should be reviewed against risk-based safety standards based on sound science and

protective of human health and the environment.

• Manufacturers should provide EPA with the necessary information to conclude that new and

existing chemicals are safe and do not endanger public health or the environment.

• EPA should have clear authority to take risk management actions when chemicals do not meet the

safety standard, with flexibility to take into account sensitive subpopulations, costs, social

benefits, equity and other relevant considerations.

• Manufacturers and EPA should assess and act on priority chemicals, both existing and new, in a

timely manner.

• Green chemistry should be encouraged and provisions assuring transparency and public access to

Information should be strengthened.

• EPA should be given a sustained source of funding for implementation.

http://ehstoday.com/environment/hazardous-waste/epa-jackson-framework-chemical-reform-5212/

A NEW APPROACH TO CHEMICAL REGULATION (TSCA Reform)

Although legislative reform is necessary for an effective chemicals management

program, Jackson said EPA is committed to strengthening the performance of the current

program while Congress considers new legislation. This enhanced plan includes the

development of chemical action plans that outline the agency’s risk management efforts

on those chemicals of greatest concern. EPA has identified an initial list of chemicals for

possible risk management action and anticipates completing and posting action plans.

An additional focus will be accelerating efforts to gather the information from industry that

the agency needs to make chemical risk determinations. This will include filling the

current gaps in health and safety data on high production volume chemicals;

enhanced, transparent, and more current reporting of use and exposure information; and

a number of requirements for increased reporting on nanoscale chemical materials. In

addition, EPA is reviewing how nanoscale materials are managed under TSCA. EPA also

is reviewing ways to increase the public’s access to information about chemicals.

http://ehstoday.com/environment/hazardous-waste/epa-jackson-framework-chemical-reform-5212/

Federal Insecticide, Fungicide and Rodenticide Act (FIFRA)

The Federal Insecticide, Fungicide, and Rodenticide Act - a United States federal law that set

up the basic U.S. system of pesticide regulation to protect applicators, consumers and the

environment. The current version of FIFRA underwent a major revision in 1972 and

superseded the Federal Insecticide Act of 1910 and the Federal Insecticide, Fungicide, and

Rodenticide Act of 1947. The act was amended somewhat in 1996 by the Food Quality

Protection Act. In 1988, it was amended again to change pesticide registration laws and to

require reregistration of certain pesticides that had been registered before 1984.

When FIFRA was first passed in 1947, it gave the United States Department of Agriculture

responsibility for regulating pesticides. In 1972, when FIFRA underwent a major revision, it

transferred responsibility of pesticide regulation to the Environmental Protection Agency and

shifted emphasis to protection of the environment and public health. The 1972 version is

largely still in place.


FIFRA established a set of pesticide regulations:

1. FIFRA established registration for all pesticides, which is only done after a period of data collection to

determine the effectiveness for its intended use, appropriate dosage, and hazards of the particular material.

When registered, a label is created to instruct the final user the proper usage of the material. If instructions

are ignored, users are liable for any negative consequences.

Label directions are designed to maximize the effectiveness of the product, while protecting the

applicator, consumers, and the environment. Critics of the process point out on the one hand that the

research to produce the label is entirely done by the manufacturer and not much checking is done on its

accuracy. On the other hand some consider the process too strict. It costs millions of dollars and often

several years to register a pesticide, which limits production only to large players. Likewise many smaller or

specialty uses are never registered, because the companies do not consider the potential sales sufficient to

justify the investment.

2. Only a few pesticides are available to the general public, and can be used by anyone who will follow

directions (general use). Most pesticides are considered too hazardous for general use, and are restricted to

certified applicators (restricted use). FIFRA established a system of examination and certification both at the

private level and at the commercial level for applicators who wish to purchase and use restricted use

pesticides. The distribution of restricted pesticides is also monitored.

3. The EPA has different review processes for three categories of pesticides:

antimicrobials, biopesticides, and conventional pesticides. The three categories have a similar application

process, but have different data requirements and review policies. Depending on the category of

pesticide, the review process can take several years. After a pesticide is registered with the EPA, there may

be state registration requirements to consider.


As of 1999, approximately 20,000 pesticides had been registered by EPA. In

2006, 26 new pesticide products were registered, 44 were amended for 186 new

uses, and 18 products were cancelled.

When a pesticide is to be registered, data showing its impact are submitted to EPA.

The EPA will register the pesticide when 4 factors exist:

1)The pesticide’s composition is such as to warrant the proposed claims for it.

2)Its labeling complies with the act

3)The pesticide will perform its intended function without unreasonable risks to

people and the environment (taking into account economic, social and

environmental costs and benefits of the pesticide)

4)When used in accordance with commonly used practice, the pesticide will not

cause unreasonable risk to the environment

What is unreasonable risk?

originally primarily carcinogenicity

today, reproductive, immunological and neurological effects of the pesticide, as

well as its impact on groundwater and on the growth and reproduction of wildlife and

fish

What constitutes a proper label?

http://www.epa.gov/pesticides/kids/hometour/label/read.htm

http://www.epa.gov/pesticides/kids/hometour/label/read.htm


Registration (lasts 5 years; unless only a conditional registration)

general use – most desirable for manufacturer, can be sold to anyone in any

quantity

Restricted use – reserved for pesticides have the potential to have an unreasonable

impact. The unreasonable effects can be mitigated or prevented if the use and/or

sale of the pesticide is restricted in some manner.

most common restriction is to limit use to certified applicators who take a test

“application by or under the supervision of a certified applicator”

What if anything might be wrong with this aspect of the statute?

exception for private applicator

must take course, but not take exam

What if anything might be wrong with this aspect of the statute?

Other possible restrictions

limited frequency of use

limited locations of sale or application

limitations on the pests that may be targeted

limits on amount used per application


Re-registration

1988 amendments set up a re-registration scheme for some pesticides. Applies to

chemicals developed prior to current health and safety standards (1984 Food

Quality Protection Act (FQPA); amended 1996)

As of 2006 613 re-registration cases for EPA to consider

90% completed (559)

330 reregistered

229 voluntarily cancelled or deregulated


Cancellation of Registration

automatic unless renewal submitted during the 5 yr. registration period

"unreasonable risk" can also justify premature cancellation; time consuming hearing

process (2yrs) during which the product remains on the market

"imminent hazard" administrator of the EPA can issue a notice to the manufacturer

that the pesticide use is being suspended within 5 days; manufacturer can request

an expedited hearing

"emergency suspension" immediate action by the EPA administrator; manufacturer

can have an expedited hearing

What should be done with pesticide stocks after their registrations have been

cancelled?

In many cases, as long as they can use their stock, manufacturers do not protest

cancellation

Although other governments will be informed by the EPA there is no regulation

making it illegal to sell the pesticide in another country

circle of poison problem


Worker Protection Standard Program

http://www.epa.gov/oppfead1/safety/workers/principl.htm

http://www.epa.gov/oppfead1/safety/workers/principl.htm

Federal Food, Drug, and Cosmetic Act (FFDCA) authorizes EPA to set

tolerances, or maximum residue limits, for pesticide residues on foods. In the

absence of a tolerance for a pesticide residue, a food containing such a residue is

subject to seizure by the government. Once a tolerance is established, the residue

level in the tolerance is the trigger for enforcement actions. That is, if residues are

found above that level, the commodity will be subject to seizure.

In setting tolerances, EPA must make a finding that the tolerance is “safe.” Safe is

defined as meaning that there is a "reasonable certainty that no harm will result

from aggregate exposure to the pesticide residue." To make the safety finding, EPA

considers, among other things: the toxicity of the pesticide and its break-down

products, aggregate exposure to the pesticide in foods and from other sources of

exposure, and any special risks posed to infants and children. Some pesticides are

exempted from the requirement to have a tolerance. EPA may grant exemptions in

cases where the pesticide residues do not pose a dietary risk under reasonably

foreseeable circumstances.

Food Quality Protection Act (FQPA) 1996

Congress presented EPA with the enormous challenge of implementing the most comprehensive and historic

overhaul of the Nation's pesticide and food safety laws in decades.

Improved Health Standards for Food Commodities

FQPA Requirement: FQPA requires a new safety standard – reasonable certainty of no harm – that must

be applied to all pesticides used on food commodities

Achievement: Tolerances, which are the maximum amount of pesticide residue allowed to remain on food

products, are set by EPA as part of the registration and reregistration processes. Under FQPA, EPA must

make a safety finding in setting tolerances that the pesticide can be used with "reasonable certainty of no

harm." To achieve the new safety standards required by FQPA, EPA has refined its risk assessment methods

and added new risk assessments, e.g. aggregate and cumulative. This task sent EPA into novel scientific

inquiry and forced the development of cutting edge scientific methods and policy. As a result of EPA's

strenuous efforts and inventive solutions, all pesticide tolerances now meet the stringent health standard set

by FQPA.

FQPA Requirement: FQPA requires EPA to reassess all existing tolerances within 10 years

Achievement: Pesticide tolerances that were in place as of August 1996, when the Food Quality Protection

Act was signed, are subject to reassessment under the new safety standards of FQPA. EPA has completed

nearly all of this work, having reassessed 9637 or over 99% of the 9,721 tolerances required by FQPA. This

reassessment is scheduled to be completed shortly. This complex scientific effort required the detailed

review of tens of thousands of studies and test results on toxicity, chemistry, and environmental

data. Notably, this work resulted in the revocation or modification of almost 4,000 food tolerances.

FQPA Requirement: FQPA requires EPA to set tolerances for residues resulting from uses allowed under

FIFRA section 18 emergency exemptions

Achievement: EPA created a program for setting time-limited tolerances for emergency exemptions on an

expedited basis. This program, which became operational for the 1996 use season, has enabled EPA to

work rapidly and efficiently with our co-regulator States. As a result, there are minimal disruptions in the

emergency exemption approval process and maximum efficiency in responding to such situations. EPA has

made approximately 500 annual decisions on emergency exemptions most years since 1996.

FQPA Requirement: FQPA requires EPA to consider risks to infants and children when setting tolerances

Achievement: In accordance with FQPA, all tolerance decisions take into account the special susceptibility

of children to pesticides. EPA has cancelled use of several OP pesticides on many “kid” foods, such as

apples, and utilizes an additional tenfold (10X) safety factor as appropriate in setting and reassessing

tolerances.

FQPA Requirement: FQPA requires EPA to consider all "aggregate risk” from exposure to a pesticide from

multiple sources when assessing tolerances

Achievement: Through consultation with the FIFRA Scientific Advisory Panel (SAP), the Tolerance

Reassessment Advisory Committee (TRAC), and the Committee to Advise on Reassessment and Transition

(CARAT), EPA has developed sound scientific procedures for evaluating aggregate exposures to pesticides.

These new and improved procedures have enabled EPA to conduct risk assessments that combine

exposures from dietary, residential, and drinking water sources, and to ensure that exposure to pesticides in

food are safe in light of the aggregate exposure.

FQPA Requirement: FQPA requires EPA to consider "cumulative exposure" to pesticides that have

common mechanisms of toxicity

Achievement: EPA has identified four groups of pesticides that share a common mechanism of toxicity:

organophosphates (OPs); n-methyl carbamates; triazines; and chloroacetanilides. In assessing cumulative

risks, EPA evaluates the potential for people to be exposed to more than one pesticide at a time from a group

with an identified common mechanism of toxicity.

FQPA Requirement: EPA developed science policies regarding risk assessments

Achievement: In order to implement the new risk assessment standards, EPA had to develop new science

policies. EPA met this challenge by working with the Tolerance Reassessment Advisory Committee, as well

as other committees and panels, to identify science policy issues that were key to the implementation of

FQPA and tolerance reassessment. New science policies were developed rapidly and effectively, especially

in light of the unexplored nature of the scientific areas involved; they represent a significant aspect of EPA's

achievements in regard to FQPA. The new science polices include guidelines regarding: a tenfold safety

factor; dietary exposure and risk assessment; threshold of regulation; drinking water exposure; residential

exposure; aggregate exposure and risk assessment; cumulative risk assessment for pesticides with a

common mechanism of toxicity; cholinesterase inhibition end point; and use and usage information.

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Controlling toxic substances 2012