What do we do to address chemicals and processes that have become obsolete due to regulatory restrictions? This intriguing question, posed by Controlled Environments readers in a recent survey, has a multilayered answer. It is important to know what processes and/or chemicals have become truly obsolete or severely restricted, because, wherever possible, it is prudent to avoid changes for reasons that are not related to product performance or surface quality. Process changes potentially impact contamination control, product quality, and public and/or patient safety. This is true for chemicals used as part of critical cleaning processes as well as for other process chemicals.
WHY ARE CHEMICALS RESTRICTED OR OBSOLETE?
A chemical may be restricted because one or more regulatory agencies determine that continued use or relatively unrestrictive use may adversely impact the health or safety of workers, the general community, or the overall environment. This impact can either occur directly via toxicity or because release of the chemical may have negative environmental consequences to air, water, or soil that then impact the health of living organisms.
For example, many organic chemicals are classified as Volatile Organic Compounds (VOCs). They are regulated, restricted, or controlled, particularly in areas of poor air quality, due to their proclivity to produce tropospheric ozone (smog). Environmental regulatory agencies may restrict the usage of VOCs in a given manufacturing facility. The details of these restrictions vary depending on the geographical area. They can also vary depending on the manufacturing application; exemptions may be based on advocacy or lobbying.
A few compounds are classed as negligibly reactive or VOC-exempt; in many areas this means relatively few usage restrictions. Many manufacturers attempt to use such chemicals wherever possible in a process, whether or not optimal surface quality or contamination control is achieved. The VOC exemption status is determined initially at the Federal level. Some compounds are much more efficient at producing undesirable ozone than others. At the Federal level, VOC status is analogous to an on/off switch, with compounds having reactivity below that of ethane treated as negligibly-reactive. Organic compounds are considered to be VOCs unless demonstrated to the EPA that they are negligibly reactive. This can be an exhaustive, exhausting, and politically-charged process that may take over a decade. There is also the opportunity for a sort of “biofeedback loop” from the states to the Federal government in the sense that the management of VOCs can be modified through the State Implementation Plan (SIP) that is submitted back to the Federal government. This is important in that, for example, some SIPs may call out vapor pressure limitations on the grounds that low vapor pressure fluids are slower to impact tropospheric ozone. However, cleaning agents and process fluids with lower vapor pressure also tend to be harder to rinse and leave more residues. There is also the issue of relative reactivity. If a relative reactivity scale were used, instead of the on/off switch, it would open the opportunity for blended process fluids to reduce the net ozone producing reactivity. In California, the SIP includes some opportunities for this to happen.
The desirability of ozone is location dependent. In the troposphere, the problem is keeping the level of ozone sufficiently low. In the stratosphere, where ozone helps to protect the lower atmosphere and surface from damaging UV radiation, the problem is ozone depletion. Production of ozone depleting chemicals is controlled through the Montreal Protocol; and, at the Federal level within the EPA, by the Significant New Alternatives Policy (SNAP) Program. CFC-113 and 1,1,1-trichloroethane were phased out of production through SNAP activities; and the phase-out of HCFC-225, including a usage ban is set for the beginning of 2015.
Some chemicals are classed as Hazardous Air Pollutants (HAPs) at the Federal level. The management of these air toxics is through one or more of the numerous, voluminous National Emission Standards for Hazardous Air Pollutants (NESHAPS). For example, the Halogenated Solvents NESHAP describes process control measures for classic chlorinated solvents like perchloroethylene. With air toxics, there are issues of overall environmental quality as well as of local neighborhood safety.
Worker exposure is a separate regulatory issue. Allowable worker exposure, as distinct from community or environmental exposure, is determined at the Federal level by OSHA. OSHA can set legally enforceable PELs. The OSHA process has been slow, for a variety of reasons. There are other sources of worker exposure numbers, including those set by individual manufacturers and by professional organizations such as AIHA and ACGIH. In addition, states can also set legally-enforceable PELs, as long as the numbers are not higher (less restrictive) than those set by OSHA. In California, Cal/OSHA has been active in setting PELs that are often much lower than those set by the Federal government.
Environmental regulations are also in place to assure acceptable water quality. These regulations may be local, regional, Federal, or even global. Water quality regulations may impact management of process baths. Where there are global problems, formulators may choose to use a substitute additive.
In the next column, we will discuss the role of the EPA SNAP group in restricting chemical production or use. We will also explore the scope of the word “banned.”
Barbara Kanegsberg and Ed Kanegsberg, Ph.D. “The Cleaning Lady” and “The Rocket Scientist,” are independent consultants in surface quality including critical/precision cleaning, contamination control, and validation. They are editors of the expanded, updated two-volume second edition of “The Handbook for Critical Cleaning,” CRC Press. Contact BFK Solutions LLC, 310-459-3614; firstname.lastname@example.org.