Threshold determination

A covered multi-establishment facility must make chemical threshold determinations and report all relevant information about releases and waste treatment associated with a listed chemical, even from establishments that are not in SIC codes 20-39. EPA realizes, however, that certain establishments in a multi-establishment facility can be, for all practical purposes, separate business units. Therefore, individual establishments may report separately, provided that the total release is reported for the whole facility is represented by the sum of releases reported by the separate establishments. 

An auxiliary facility is one that supports another facility s activities (e.g., research and deveiopment iaboratories, warehouses, storage facilities, and waste-treatment facilities). An auxiliary facility can take on the SIC code of another covered facility if its primary function is to service that other covered facility s operations. Thus, a separate warehouse facility (i.e., one not located within the physical boundries of a covered facility) may become a covered facility because it services a facility in SIC codes 20-39. Auxiliary facilities that are in SIC codes 20-39 are required to report it they meet the employee criterion and chemical thresholds for manufacture, process, or use. Auxiliary establishments that are part of a multi-establishment facility must be factored into threshold determinations for the facility as a whole. 

A separate worksheet would be completed for each section 313 chemical or chemical category. Chemicals which are listed with specific qualifiers (e.g., solution manufacture) require that the threshold determinations only be based on the amount of the chemical meeting the qualifier. Use of the worksheet is divided into three steps ... 

Do not add together the quantities of the chemical that are manufactured, processed, and used at yourfacllity, because each of these activities requires a separate threshold determination. For example, if in 1989 you processed 20,000 pounds of a chemical and you otherwise used 6,000 pounds of that same chemical, your facility has not met or exceeded any applicable threshold and thus is not required to report for that chemical. 

Also note that threshold determinations are based upon the actual amounts of a chemical manufactured, processed, or used over the course of the calendar year. The threshold determination may not relate to the amount of a toxic chemical brought on-site during the calendar year. For example, a stockpile of 100,000 pounds of a toxic chemical is present onsite but only 20,000 pounds is applied to a process Therefore, only the 20,000paunds processed is counted toward a threshold determination, not the entire 100,000 pounds of the stockpile... 

Threshold Determinations for On-Site Reuse/Recvde Operations. 

This exemption does not apply to toxic chemicals "recycled" off-site and returned to the facility. Such toxic chemicals returned to the facility are treated as the equivalent of newly purchased material for purposes of section 313 threshold determinations. 

Threshold determinations for metal-containing compounds present a special case. If, for example, you process several different lead compounds, you would base your threshold determination on the total weight of all lead compounds processed. However, If you process both the parent" metal (lead) as well as one or more lead compounds, you must make threshold determinations for both because they are separately listed toxic chemicals. If you exceed thresholds for both the parent metal and compounds of that same metal, EPA allows you to file one combined report (e.g., one report for lead compounds, including lead) because the release Information you will report In connection with metal compounds will be the total pounds of the parent metal released. 

A chemical manufactured at the facility that does not remain in a product distributed by the facility. A threshold determination must be made on the annual quantity of the chemical manufactured regardless of the concentration. For example, quantities of formaldehyde created as a result of waste treatment must be applied toward the threshold for manufacture of this chemical, regardless of the concentration of this chemical in the wastestream. 

In general, when the de minimis applies to threshold determinations and the concentration of the chemical in the mixture is below the de minimis, then you are not required to report releases associated with the processing or use of the chemical In that mixture. Note that it is possible to meet the threshold for a chemical on a facility-wide basis, but not be required to calculate releases from a particular process because that process involves only mixtures containing the chemical below the de minimis level. 

Leonardos G, Kendall D, Bernard N. 1969. Odor threshold determinations of 53 odorant chemicals. J Air Pollut Control Assoc 19 91-95. 

Table 11. Energies for Reaction M+L = M+ + L from CID Threshold Determinations ...

Figure 41. The percolation threshold determination for polymer blends undergoing the phase separation. Minority phase volume fraction, fm, is plotted versus the Euler characteristic density for several simulation runs at different quench conditions, /meq- = 0.225,..., 0.5. The bicontinuous morphology (%Euier < 0) has not been observed for fm < 0.29, nor has the droplet morphology (/(Euler > 0) been observed for/m > 0.31. This observation suggests that the percolation occurs at fm = 0.3 0.01.

In reality the limiting case it not complete loss of activity but rather reduction of activity below a critical threshold determined by the economics of any given process and reactor design. 

Leonardos, G., Kendall, D.A., and Barnard, N.J. 1968. Odor threshold determinations of 53 odorant chemicals. Presented at the 61th Annual Meeting of die Air Pollution Control Association, St Paul, Minn., June 23—27. [Requested. NIOSH, 1976, page 29]... 

Condensation can be avoided by the predilution of the sample by diy, odour-free air. It is important to know in which ratio the sample is diluted for odour unit or odour threshold determination. 

VDI Guideline 3881 Olfactometric method of odor threshold determination, Fundamentals (Nov., 1983)... 

GENERAL CONDITIONS OF ODOR THRESHOLD DETERMINATION 2. 1 Requirements for the test area... 

In selecting the stimulus continuum in threshold determination, the relation between just noticeable difference in relation to the intensity of stimuli is of interest. In accordance with Weber s law this quotient is assumed to be a constant. Therefore it would appear best to determine absolute thresholds on an intensity continuum in the form of a geometric progression. 

Olfactometry—Odour Threshold Determination—Olfactometers Types 1158 and TO-4... 

Olfactometry—Odour Threshold Determination—Instruction for Application and Performance Characteristics... 

The published guideline VDI 3881 /2—4/ describes, how to measure odour emissions for application in dispersion models. Results obtained by this method have to be completed with physical data like flow rates etc. As olfactometric odour threshold determination is rather expensive, it is supplemented with tracer gas emissions, easy to quantify. In the mobile tracer gas emission source, fig, 2, up to 50 kg propane per hour are diluted with up to 1000 m2 3 air per hour. This blend is blown into the open atmosphere. The dilution device, including the fan, can be seperated from the trailer and mounted at any place, e.g. 

LEONARDOS, G., D.KENDALL and N.BARNARD (1969). Odor threshold determination of 53 odorant chemicals. J.AirPoll. Contr. Assoc. 19, 91-95. 

McCue D, Ryan K, Wraith DC, Anderton SM Activation thresholds determine susceptibility to peptide-induced tolerance in a heterogeneous myelin-reactive T cells repertoire. J Neuroimmunol 2004 156 96-106. 

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