An update
More and more companies have replaced 1,l,1-trichloroethane with
alternative chlorinated solvents, as permitted under the Significant
New Alternatives Policy (SNAP) issued by the U.S. Environmental
Protection Agency (EPA). Companies specifying these solvents for their
processes, however, must be aware of the numerous federal, state and
local regulations governing their safe and environmentally responsible
handling, storage and disposal.
To assist these companies in planning their processes and
developing their product stewardship programs, we have listed the
principal U.S. federal and state regulations. This is not an
exhaustive list of course, and it is impossible to reference all the
applicable regulations in our limited space; consequently, we urge our
readers to consult with their environmental legal consultants about
this matter. The following notes, however, should be helpful as a
preliminary survey and a checklist.
Ozone Depleting Substances
The Clean Air Act Amendments (CAAA) of 1990 legislated the phaseout
by December 31, 1995, of several ozone depleting substances (ODS),
including the widely used chlorinated solvent 1,1,1-trichloroethane
(also known as methyl chloroform or MCF). The Act also established
labeling requirements for products containing an ODS or manufactured
by processes making use of an ODS. In addition, Congress passed a law
imposing an incrementally growing excise tax on ODSs.
The other three widely used chlorinated solvents, methylene
chloride (MEC), perchloroethylene (PCE) and trichloroethylene (TCE),
are not listed as contributing to ozone depletion. As a result, they
are not included under this legislation; they are not scheduled for
phaseout or subject to excise tax or ODS labeling requirements.
Another portion of the CAAA chartered EPA to establish a SNAP rule
to determine acceptable substitutes for the ODSs. Under the SNAP rule
issued in March 1994, MEC, PCE and TCE are listed as acceptable
alternatives for 1,1,1-trichloroethane in a variety of applications.
VOC Regulations
Under the CAAA, trichloroethylene is controlled as a volatile
organic compound (VOC) which acts as a precursor of smog. Limitations
are placed on emissions of this solvent, in particular in ozone
non-attainment areas, in order to reduce smog formation. Exact
regulation requirements vary by state, but they generally include
obtaining a permit which allows a specified amount of VOC emissions
from all sources within a facility. Controls must then be installed in
order to stay within these limits.
Because of their negligible photochemical reactivity, PCE and MEC
are exempt from CAAA regulations governing VOCs, and most states also
do not control the solvents as VOCs. Some states, however, exercising
their right to enact regulations more stringent than the federal
guidelines, do control them in some or all of their VOC rules. Readers
should contact their local regulatory authority for the status of PCE
and MEC in their area.
Hazardous Air Pollutants
The chlorinated solvents have been designated as hazardous air
pollutants (HAPs) by EPA, but although the CAAA calls for regulations
on MEC, PCE and TCE as HAPs, a complete set of regulations have not
been issued for their control. EPA has, however, issued a final
National Emission Standards for Hazardous Air Pollutants (NESHAP) for
PCE drycleaning facilities (see the Federal Register, Vol.58, No. 182,
4935449380), for solvent cleaning with chlorinated solvents (Federal
Register, Vol. S9, No. 231,61801-61820) and for aerospace depainting
(Federal Register, Vol.60, No. 170,4594845980). The CAAA calls for the
development of Maximum Available Control Technology (MACT), which will
eventually be required for all solvent cleaning sources using
chlorinated solvents.
Other NESHAPs have been, and are expected to be, proposed for other
applications involving chlorinated solvents use. Some of these have
become final rules and others will become final in the near future.
These include wood furniture manufacturing and asbestos brake
cleaning, among others.
Many states have already enacted HAP regulations or Toxic Air
Contaminant regulations for lists of chemicals, which usually include
chlorinated solvents. These regulations frequently require the use of
Best Available Control Technology (BACT), with carbon adsorption or
its equivalent a common compliance method. Some states also require
risk assessment and/or monitoring. Users of chlorinated solvents
should contact the applicable state Air Pollution Control authority to
determine what requirements must be followed.
Inhalation Exposure
Permissible Exposure Limits (PELs) set by the Occupational Safety
and Health Administration (OSHA) and recommended Threshold Limit
Values (TLVs) established by the American Conference of Governmental
Industrial Hygienists (ACGIH) have been in force for the chlorinated
solvents over a number of years. In 1989 OSHA proposed a downward
revision of the workplace PELs for a number of substances, including
perchloroethylene and trichloroethylene (see Table 1).
This was overturned in 1992 by the U.S. Court of Appeals for the
Eleventh Circuit, sending workplace standards back to the limits set
prior to 1989 until OSHA could develop a new standard. The Dow
Chemical Company recommends controlling exposure to the chlorinated
solvents below OSHA's 1989 PELs, or the ACGIH guidelines, whichever is
lower.
Hazard Communication Training
According to OSHA's Hazard Communication (HAZCOM) rule, training on
hazardous chemicals in the workplace is required for all employees who
could be exposed to the chemicals. New employees must be trained at
the time of their initial assignment, and supplemental training is
required for all employees when a new hazard is introduced into their
work area. OSHA specifies minimum elements of the "mining. These
include how to detect the presence or release of the chemical, the
hundreds of the chemical and what protective measures should be used.
Labeling Requirements
OSHA's Hazard Communication Standard, which regulates products
containing hazardous chemicals, requires that containers of these
hazardous chemicals in the workplace and leaving the workplace be
marked with an "appropriate hazard warning label." The label must also
contain the identity of the name and address of a responsible party.
This is a performance-oriented regulation; consequently, the details
for giving the "appropriate" warning are not specified. Guidelines are
provided by an OSHA compliance document (OSHA Instruction No.
CPL-2-2.38 C (1990)), and by the American National Standards Institute
(ANSI) publication on precautionary labeling (ANSI Z129.1- 1994). In
addition, if a product containing a hazardous chemical is intended for
consumer use, Consumer Product Safety Commission (CPSC) regulations
should be consulted (16 CFR 1500).
For example, in 1987, the Consumer Product Safety Commission voted
to issue a Statement of Policy for household products containing
methylene chloride rather than issuing a formal rule. The policy
statement designates methylene chloride as a hazardous substance under
the Federal Hazardous Substance Act (FHSA) and establishes labeling
guidelines for consumer products containing methylene chloride
(including paint strippers, wood stains and varnishes, spray paints,
adhesives and glues and a number of other household products). A
statement of interpretation and enforcement policy appeared in the
Federal Register, Vol. 52, No. 177, September 14, 1987. The policy
requires labels to include the statement: "Methylene chloride has
caused cancer in certain laboratory animal tests. Risk to your health
depends on duration and level of exposure."
In addition to the federal labeling regulations, individual states,
including California, New Jersey, New York and Pennsylvania, may have
specific labeling requirements.
Waste Disposal
Under the federal Resource Conservation and Recovery Act (RCRA),
waste containing chlorinated solvents from solvent cleaning operations
must be considered hazardous waste. This means that an acceptable
disposal method for such waste is required. In addition, wastes must
be transported by a certified hazardous waste hauler, stored in a
licensed storage facility, disposed of in licensed treatment and
disposal facilities and their appropriate EPA and state identification
numbers must be kept on file, easily retrievable for reference.
Dow advises all customers to refrain from disposing of chlorinated
solvents or solvent-containing wastes in landfills or deep wells. The
preferred disposal method is to send the material, via a permitted
waste hauler, to a licensed reclaimer or a permitted incinerator, in
compliance with federal, state and local regulations.
Reporting Spills or Releases
The federal Comprehensive Environmental Response, Compensation and
Liability Act (CERCLA, or Superfund) states that if a "reportable
quantity" (RQ) of a chlorinated solvent-either alone or in a
mixture-is released to the environment in any 24-hour period, federal,
state and local authorities must be notified immediately. The
reportable quantities for each of the solvents are: methylene
chloride: 1000 lbs; perchloroethylene: 100 lbs; trichloroethylene: 100
lbs; 1,1,1-trichloroethane: 1,000 lbs.
Another federal law, the Emergency Planning and Community Right to
Know Act (or SARA Title m), imposes additional reporting requirements
on some solvents. Consult the MSDS to see whether these requirements
apply to the product you purchase.
Toxic Pollutants
Under the federal Clean Water Act, the chlorinated solvents are
defined as Toxic Pollutants (also called Priority Pollutants), and
their discharges into waterways are regulated. Different regulatory
requirements may be demanded of direct dischargers (who discharge
directly into a waterway) and indirect dischargers (who discharge into
a water treatment system). In addition, state and local governments
may have additional regulations concerning the discharge of waste
water containing these solvents.
For Further Information
As we mentioned, this guide is not presented or intended as an
exhaustive resource, especially in such a rapidly changing field as
environmental, health and safety regulations. Dow strongly recommends
that readers consult with their regulatory and legal counsel to
determine which regulations ae applicable to their particular
operations and applications.
Reprinted From Choices & Solutions, Volume: 2 Issue:
2, a publication of the Chemicals & Metals Department of The Dow
Chemical Company
