Coating Materials News Vol 7 Issue 1

January - March, 1997

Waste Management Considerations in Vacuum Deposition Processes
by Gerard E. Manley
Safety and Environmental Manager
CERAC, inc.

Important Note:
Nothing in this article should be construed as legal advice. It is for informational purposes only. Each generator of waste is ultimately responsible for evaluation of all federal, state and local regulations to determine proper classification of the waste and the applicability of regulations to your business in order to identify appropriate actions necessary for compliance. At the international level, it is important to understand the regulations of the specific country in which you are dealing.

Overview:
One aspect of the vacuum deposition process that this newsletter has yet to address is the issues involving waste management. Whereas the readers of this newsletter are technically knowledgeable in the theory and application of thin film technology, this same group may likely be less knowledgeable of the often confusing regulations governing proper generation, transportation and disposal of wastes created from these processes. While the intent is not to make anyone an expert, it is beneficial to understand the fundamental concepts of waste management. This initial article will focus on what makes a waste a regulated hazardous waste. Future newsletters will focus on regulatory obligations of generators of hazardous waste.

At the federal level, the agency primarily responsible for developing regulations governing the protection of the environment is the Environmental Protection Agency. Formed as an independent Administrative Agency within the Executive Branch in 1970, EPA was directed by Congress to establish regulations overseeing the management of solid and hazardous wastes following the 1976 promulgation of the Resource Conservation and Recovery Act (RCRA).

RCRA identifies the minimum requirements that State regulatory agencies must enforce for the management of solid and hazardous wastes. Each individual state has the authority to go beyond RCRA, enacting stricter standards as it deems appropriate. Each business must evaluate the specific state, and in some cases, local regulations to fully understand the regulatory burden of which compliance is expected.

Waste Streams:
An excellent starting point in understanding hazardous waste management issues is to first properly identify the "waste streams" generated by your processes. Waste stream is the term used to identify each individual source of waste, be it from the installation, start-up, operation, or cleaning of a process. It is important to understand in detail the physical and chemical nature of each waste stream. While many waste streams may be obvious, it is very easy to overlook some waste streams that ultimately may need to be managed as a hazardous waste.

Examples of typical waste streams from vacuum deposition include:

• Spent coating materials and their source containers. (i.e. boats, filaments, crucibles, liners, sputtering targets, cathodes, etc.)
• Masking materials, such as aluminum foil, used to shield the chamber interior
• Sand from sandblast cleaning of tooling, or wipe-down sand paper and towels, either dry or solvent soaked
• Scrap coated optical or metal pieces
• Used solder from metallic bonding of targets to backing plates

Once all of the waste streams are identified and the physical and chemical nature of these streams are "characterized", it is then appropriate to evaluate the applicable regulations to determine which waste streams must be managed as hazardous waste.

Criteria for Identifying Hazardous Waste:
EPA Regulations are compiled in the Code of Federal Regulations at Chapter 40 (40 CFR). Specific regulations concerning hazardous waste management begin at 40 CFR Part 260. Part 261 addresses the identification and listing of hazardous waste.

Within these regulations you can find detailed and often complicated definitions of common terminology used in Hazardous Waste Management. In addition, numerous exemptions and exceptions to specific regulations are listed. Developing a working knowledge of this information is important for the personnel responsible for managing hazardous waste within your business. This article attempts only to provide a general understanding of the major driving forces within this regulation.

Waste may be classified as hazardous waste by either exhibiting a defined characteristic of hazardous waste (Part 261 Subpart C) or by being specifically listed as a hazardous waste on one or more of numerous lists (Part 261 Subpart D).

Characteristics of hazardous waste include the following: ignitability, corrosivity, reactivity, and toxicity.

Heavy Metal Wastes:
Among the representative waste streams for vacuum deposition processes previously noted, the attribute of primary concern is that of toxicity. A procedure entitled the Toxicity Characteristic Leaching Procedure (TCLP) test is used to determine if a waste must be managed as a hazardous waste due to toxicity. Table 1 of Part 262.24 identifies the contaminants and the regulatory limits for the TCLP.

Contaminants of particular concern to the vacuum deposition industry in the following Table are the "heavy metals". Of the 40 contaminants listed, 8 are inorganic and the remaining 32 are organic. The inorganic contaminants and the regulatory level for the TCLP test are listed in the adjacent table.