BENPAT and PREPOD: guide to reporting

Starting with the 2020 reporting year, 2-Propanone, reaction products with diphenylamine, also known as PREPOD [Chemical Abstracts Service Registry Number (CAS RN 68412-48-6] and 1,4-Benzenediamine, N,N’-mixed phenyl and tolyl derivatives, also known as BENPAT (CAS RN 68953-84-4) are required to be reported to the NPRI.

Reporting of BENPAT and PREPOD

You MAY have to report on BENPAT and PREPOD if:

• your facility has more than 10 employees or your facility does any of the activities for which reporting is required regardless of the number of employees (for example incineration or discharge of treated or untreated wastewater from a wastewater collection system discharging an average of ≥ 10 000 m3/day into surface waters) and
• your facility manufactures, processes or otherwise uses the substance at or above the substance thresholds (On annual basis).

(*) The concentration threshold applies to quantities of the substance that are manufactured, processed or otherwise used, whether as a raw material or in other processes or products/mixtures at the facility. It does not apply to incidental manufacture, processing or other use of the substance as a by-product.

You should review the Guide for reporting to the NPRI for more information on how to determine whether you meet the thresholds for these substances, and to determine whether reporting on other substances is required.

BENPAT and PREPOD are found on Part 1B of the NPRI substance list and the reporting for these substances is in kilograms.

Reporting to the NPRI is broken down into a number of categories:

• on-site releases: a discharge of a substance to air, water or land within the physical boundaries of the facility
• on-site disposals: disposal at the facility, such as to landfill
• off-site disposals: materials sent to another facility for disposal, such as to landfill or storage prior to final disposal
• off-site transfers for treatment prior to final disposal: materials sent to another facility for treatment, such as to a municipal wastewater treatment plant
• off-site transfers for recycling and energy recovery: materials sent to another facility instead of being disposed of, such as being sent back to a manufacturer, supplier or recycler for reprocessing, repackaging, resale or for credit or payment

A) Collect information

If you need to report BENPAT or PREPOD, you will need to collect information in order to calculate what was released, disposed of and sent for recycling from your facility. Some sources of information include:

• Safety Data Sheets (SDS)
• waybills for recycling and disposal
• provincial permits
• manufacturer’s information
• compounds’ recipes (Rubber compounders and tire and rubber products manufacturing)

B) Determine sources of releases, disposals and transfers

Some examples of sources of releases, disposals and transfers that are likely to occur in facilities that manufacture, process or otherwise use BENPAT and PREPOD include:

• releases to air from handling and weighing of the substances and transferring them to smaller plastic bags or containers depending on the compound recipes
• releases to surface waters (spills, leaks, discharges) from floor scrubbing (Zamboni discharge), equipment washing/blowdown, cooling of compounds or collection of curing press steam condensate (Note that releases to sewers connected to a municipal wastewatertreatment plant should be reported as off-site transfers for treatment and not as releases to water)
• releases to land (spills or leaks) associated with material transfer between packaging and storage
• off-site disposal of water-based "anti-tack" solution sludges or used solution
• off-site disposal of off-specification rubber products or trimmed rubber parts containing BENPAT or PREPOD

C) Calculate the quantities to report  

Appendix 1 contains technical information on how to estimate releases from the manufacture, processing and other use of BENPAT and PREPOD.

Estimates of the quantity of a substance that is released, disposed of or transferred for recycling may be based on one of the following methods:

• continuous emission monitoring systems
• predictive emission monitoring
• source testing
• mass balance
• site-specific emission factor
• published emission factor
• engineering estimates

The online reporting system only allows one basis of estimate (method) for each type of release, disposal and transfer. If more than one basis of estimate is used to arrive at a single quantity to be reported, select the basis of estimate that was used to calculate the majority of the value. Further explanation on the basis of estimate can be provided in the comment fields found on the main pages for reporting releases, disposals and transfers for recycling in the online reporting system.

Information on releases, disposals and transfers for recycling needs to be reported if you (the facility owner/operator) possess the information or may reasonably be expected to have access to the information. If emissions are already monitored or measured under provincial or federal legislation or a municipal bylaw, those measurements must be used to report to the NPRI. However, all releases, disposals or transfers off site for recycling must be included in threshold calculations and reported, unless otherwise specified, not just those that are measured or monitored.

An NPRI report is mandatory for any substances that meet the NPRI reporting thresholds regardless of whether the substance is being measured or monitored for other jurisdictions. If emissions are not monitored or measured under provincial or federal legislation or a municipal bylaw, reasonable efforts must still be undertaken to gather information on releases, disposals and transfers of a substance. What is “reasonable” depends on individual circumstances, but may include additional monitoring by the facility for NPRI substances.

You will need to file your report to the NPRI using Environment and Climate Change Canada’s Single Window system.

There is a series of online video tutorials which can help guide you through the process of setting up your account in Single Window (if this is the first year that the facility is required to report to the NPRI) and filling and submitting your report.

If you still have questions about reporting, you can contact the NPRI helpdesk for assistance.

Appendix 1 – How to calculate the quantities to report

Appendix 1 provides guidance on how to calculate releases, disposals and transfers of BENPAT and PREPOD from the manufacturing of PREPOD and BENPAT and from the tire and rubber products manufacturing sectors. If you have them, you may use site-specific methodologies in place of the guidance provided below.

This document does not discuss potential use of BENPAT and PREPOD by sectors other than the tire and rubber products (solid rubber and latex) manufacturing sectors.  You must still report any releases, disposals or transfers of BENPAT or PREPOD if you meet the NPRI employee threshold and the applicable thresholds for these substances.

Section 1 - Manufacturing of BENPAT and PREPOD

This section describes how to estimate releases, disposals and transfers from the production of BENPAT and PREPOD. The production of a substance starts with the actual chemical reaction (which occurs in reactors, either batch and continuous) in which the substance is formed. Substances may be released during this reaction and end up in air or wastewater. Further releases to air and wastewater may also occur during unit separation operations which occur after the initial reaction (e.g. distillation, filtration, crystallization, and extraction), due to equipment spills and leaks (valves, flanges, connectors, pumps) or during storage or cleaning operations. Furthermore, the production process may generate wastewater, sludge and spent solution which may contain the substances; further consideration should be given to disposals and transfers for treatment or recycling.

Air releases

Method  1 - monitoring and testing

If emissions are already monitored or measured under provincial or federal legislation or a municipal bylaw, those measurements must be used to report to the NPRI as they are tied directly to the conditions of process operations at the facility. If BENPAT and PREPOD are released to air as solids, the quantities released may be estimated using either the composition of the particulate matter released to air (if available), or the concentrations of BENPAT and PREPOD in the bulk material, combined with the particulate matter release quantities.

As BENPAT and PREPOD are UVCB substances, special consideration should be taken when using measurements to estimate their releases.  The following approach can be used to estimate the releases of these substances based on the monitoring or measurement of their main components. This approach assumes that the main components (see Substance Information) have similar physico-chemical proprieties, transport processes and environmental fate. It also takes into account the main source fraction of each component from the UVCB produced at the facility as well as those from other sources if the facility also manufactures, processes or uses these components individually or as part of other multi-constituent substances (other than BENPAT or PREPOD). For example, Diphenylamine (DPA) is considered one of the main components of PREPOD but it can also be used as a raw material for other manufactured antidegradent products; in this case, the fraction of DPA not associated with PREPOD should not be included in the quantities of PREPOD reported to the NPRI. Use the following equation to calculate releases of BENPAT or PREPOD based on measurements of their components:

M_i = (A_ij x F_ij) / X_ij

• M_i: quantity of substance i released per year, in kg (i= BENPAT or PREPOD)
• A_ij: monitored or measured quantity of the component j present in the substance i, in kg per year
• f_ij: source fraction of component j from the substance i
• x_ij: fraction of the component j present in the substance i

If measurement of more than one main component is performed, the calculated release quantity of BENPAT or PREPOD can be based on:

• the component that is subject to the existing Canadian federal regulatory requirements (Regulatory and non-regulatory instruments)
• existing provincial or By-Laws permitting such as Ontario ECA, etc.
• the average calculated quantity M_i (See note below)
• the largest volatile or least volatile component respectively for gas sampling or particulate matter analysis.

Note:

When the difference between the calculated maximum M_i and minimum M_i is above 20%, the estimation of M_i should be based on the last bullet by using the largest volatile or least volatile component respectively for gas sampling or particulate matter analysis;

When performing this type of calculation, it is important to take into consideration the precision and the accuracy of the analytical method used for each component as they will potentially have an impact on the calculated release quantities for BENPAT or PREPOD.

For guidance on how to report data which is based on concentration(s) that fall below the method detection limit (MDL), please refer to the Guide for reporting to the NPRI.

Method 2 - engineering estimates: process simulator models

Chemical production facilities often make use of process simulators. These are computer models (CHEMCAD, ASPEN HYSYS, etc.) that use equations of state in conjunction with mass and energy balances to simulate chemical unit operation processes for a variety of engineering purposes such as process design, optimization and control. These process simulators can also be helpful when determining the quantities that may be released to air from different unit operations.

Method 3 - engineering estimates: other

In the absence of site-specific measurement, site-specific emission factors or release data, the following references could be used to estimate releases to air from different unit operations:

USEPA Volume 2, Chapter 16 - Methods for Estimating Air Emissions from Chemical Manufacturing Facilities,

Australia NPI Emission Estimation Technique Manual for Organic Chemical Processing Industries

The following links contain physico-chemical data for the main components of BENPAT and PREPOD or for the representative structure that may be used as a surrogate to estimate potential air releases of BENPAT and PREPOD:  

Final Screening Assessment for BENPAT

ECHA Substance Infocard: BENPAT

Final Screening Assessment for PREPOD

ECHA Substance Infocard: PREPOD

Method 4 - emission factors

In the absence of information for the above methods, facilities may use an uncontrolled emission factor of 0.05% (if applicable). This is a conservative, uncontrolled factor for releases to air from processing/industrial use which is based on the EU TGD A-Tables (European Union, 2003). This factor was used for the tire and general rubber goods generic exposure scenario (ETRMA, 2010, OECD; 2004) for anti-ageing and anti-flex cracking/anti-degradants for substances with a Vapor Pressure below 1 Pascal and a Boiling Point above 300 ⁰C. This emission factor is used by applying it in the following equation:

E=EF/100 * Q * (1 - CE/100) * CF

• E: Release of BENPAT or PREPOD in kg per year;
• Q: Quantity of BENPAT or PREPOD manufactured in tonnes per year;
• EF: 0.05, kg of BENPAT or PREPOD released respectively per kg of BENPAT or PREPOD manufactured;
• CE: Control efficiency of the air pollution control device, %;
• CF: Conversion factor, 1000 kg per tonne.

Water releases and transfers to municipal wastewater treatment plants

Method 1 - monitoring and testing

After the initial reaction, the synthesized BENPAT and PREPOD go through various separation steps. These steps may involve steam stripping or water extraction both of which generate wastewater streams. These waste streams may be treated on site and discharged directly to water bodies or discharged to a municipal sewer system. Additional releases to water may also occur from spills or cleaning processes which are not recovered and conveyed to a disposal. If releases are already monitored or measured under provincial or federal legislation or a municipal bylaw, those measurements must be used to report to the NPRI.

As BENPAT and PREPOD are UVCB substances, special consideration should be taken when using measurements to estimate their releases. The following approach could be used to estimate the releases of these substances based on the monitoring or measurement of their main components. This approach assumes that the main components (see Substance Information section) have similar physico-chemical proprieties, transport processes and environmental fate. It also takes into account the main source fraction of each component from the UVCB produced at the facility as well as those from other sources if the facility also manufactures, processes or uses these components individually or as part of other multi-constituent substances (other than BENPAT or PREPOD). For example, Diphenylamine (DPA) is considered one of the main components of PREPOD but it can also be used as a raw material for other manufactured antidegradent products; in this case, the fraction of DPA not associated with PREPOD should not be included in the quantities of PREPOD reported to the NPRI. Use the following equation to calculate releases of BENPAT or PREPOD based on measurements of their components:

M_i = [(Q * C_ij * F_ij) / x_ij] * CF

• M_i: Quantity of substance i released per year, in kg (i= BENPAT or PREPOD)
• Q: Annual flow of wastewater at a given sample collection point of the facility (e.g. final discharge point for the facility effluent or other appropriate process point inside the facility) in m³ per year
• C_ij: Monitored or measured concentration of the component j present in the releases of substance i, in μg/L
• f_ij: Source fraction of component j from the substance i
• x_ij: Fraction of the component j present in the substance i
• CF: Conversion factor = 1 x 10^-9 kg/μg x 10³ L/m³

If measurement of more than one main component is performed, the calculated release quantity of BENPAT or PREPOD can be based on:

• the component that is subject to the existing Canadian federal regulatory requirements (Regulatory and non-regulatory instruments)
• existing provincial or By-Laws permitting such as Ontario ECA, etc.
• the average calculated quantity M_i (See note below)
• the component with the largest solubility

Note:

When the difference between the calculated maximum M_i and minimum M_i is above 20%, the estimation of M_i should be based on the last bullet by using the component with the largest solubility;

When performing this type of calculation, it is important to take into consideration the precision and the accuracy of the analytical method used for each component as they will potentially have an impact on the calculated release quantities for BENPAT or PREPOD.

For guidance on how to report data which is based on concentration(s) that fall below the method detection limit (MDL), please refer to the Guide for reporting to the NPRI.

Facilities subject to the PREPOD pollution prevention planning notice are requested to conduct sampling and analysis of the PREPOD component diisopropyldimethylacridan (DIPDMA), which serves an indicator of PREPOD presence. These facilities should use the results of this sampling in order to estimate the quantity of PREPOD released to water bodies or transferred to municipal sewage treatment plants.

Sampling should be performed in accordance with generally accepted standards of good scientific practice at the time of the sampling event. The following guidance document is to provide practical advice to facility operators on the sampling of industrial wastewater effluents for PREPOD and can be used for BENPAT sampling too: Guide for sampling for reaction products of 2-propanone with diphenylamine (PREPOD, CAS RN 68412-48-6) in industrial effluents.  As described in the guidance document, samples may be submitted to the ECCC National Laboratory for Environmental Testing for analysis.

Method 2 - engineering estimates: process simulator models

Chemical production facilities often make use of process simulators. These are computer models (CHEMCAD, ASPEN HYSYS, etc.) that use equations of state in conjunction with mass and energy balances to simulate chemical unit operation processes for a variety of engineering purposes such as process design, optimization and control. These process simulators can also be helpful when determining the quantities that may be released to water from different unit operations.

Method 3 - emission factors

In the absence of information for the above methods, the facility may use an emission factor of 0.001% (if applicable). This is a conservative, uncontrolled emission factor for releases to water from tire and rubber products formulation and processing activities (ETRMA, 2010) derived for anti-ageing and anti-flex cracking/anti-degradants. This emission factor can be used as a surrogate for releases to water from the manufacturing of BENPAT and PREPOD when there are no site-specific emission factors or other appropriate published emission factors available. This emission factor was developed for highly optimized and efficient tire and rubber manufacturing activities; it is therefore suitable for use in determining BENPAT and PREPOD releases from highly optimized and automatized manufacturing processes when there are no site-specific or other appropriate published emission factors available. This emission factor is used by applying it in the following equation:

E = EF / 100 * Q * (1 - CE/100) * CF

• E: Release (release) of BENPAT or PREPOD in kg per year
• Q: Quantity of BENPAT or PREPOD manufactured in tonnes per year
• EF: 0.001, kg of BENPAT or PREPOD released respectively per kg of BENPAT or PREPOD manufactured
• CE: Control efficiency of the wastewater pollution control device, %
• CF: Conversion factor, 1000 kg per tonne

Disposal and transfers for recycling or treatment prior to final disposal

If one or more components of BENPAT and PREPOD are already monitored or measured (e.g. in sludge or transferred waste) under provincial or federal legislation or a municipal bylaw, those measurements must be used to report to the NPRI. The approaches described in the previous section should be followed to estimate the quantities of BENPAT and PREPOD that end up in disposals or transfers for recycling or treatment before final disposal.

In the absence of monitoring or measurement data, a mass balance can be used to estimate the quantity of BENPAT and PREPOD in wastewater sludge or in generated waste. The mass balance would be based on the quantity manufactured and the quantities released to air and water.

Section 2 - tire and rubber products manufacturing

This section describes how to estimate releases, disposal and transfers from the tire and rubber products manufacturing sectors.

The Canadian tire industry is represented by the North American Industry Classification System (NAICS) code 326210 (“Tire Manufacturing”). This industry includes facilities that manufacturing tires and inner tubes as well as those that retread or rebuild tires. Activities in this sector include, but not limited to:

• captive compounding
• motor vehicle tire manufacturing
• aircraft tire manufacturing
• specialty vehicle tires
• retreading of tires
• inner tube manufacturing
• tire and retreading material manufacturing

The rubber products industry (including solid or dry rubber and latex) includes the manufacturing of custom rubber compounds, hose and belting, conveyers and other rubber products but not the manufacture of tires and tubes. It is comprised of two subsectors defined by the following North American Industrial Classification System (NAICS) codes:

• NAICS 326220 - Rubber and plastic hose and belting manufacturing
• NAICS 326290 - Other rubber product manufacturing

Tire and solid rubber products manufacturing sector description

The processes used in tire and solid rubber manufacturing are generally very similar. However, there may be some differences in the rubber material (natural or synthetic) used, the chemical additives added, and the type of curing employed, depending on the final product(s).

The manufacturing of tire and solid rubber products follows six principal steps (Cheminfo, 2013; USEPA, 2005):

• Mixing - mixing of raw materials into a rubber compound, including weighing and preparation of raw material
• Milling - pre-forming and warming of compound in preparation for forming
• Forming - forming the compound into the desired finished shape including calendaring and extruding
• Building - combining the compound with other resins or materials
• Curing - vulcanizing the compound into an elastomer; and
• Finishing - preparing the final shape, form, or appearance of product

Overall, these steps are dry processes or done using indirect contact water. However, releases to water can still occur as a result of floor scrubbing, equipment washing/blowdown, direct water cooling of extruded compounds, collection of curing press steam condensate, accidental overflow from anti-tack water tanks or sanitary and other miscellaneous wastewater. Air emissions may occur from these steps particularly when storage and weighing occur since the manipulation of BENPAT and PREPOD in pellet or powder forms could generate air releases. Furthermore, the production process may generate off-specification rubber parts, anti-tack sludge and spent solution which may contain these substances and further consideration should be given to disposals and transfers of these types of materials.

Rubber latex products manufacturing sector description

BENPAT or PREPOD may be used in latex rubber goods as antidegradant additives. Latex rubber is an emulsion or dispersion of natural or synthetic rubber (e.g., SBR, natural rubber) in water. There is a variety of products made from latex rubber including dipped goods like surgical gloves and balloons as well as other applications such as latex extrusion for thread manufacturing for garments, latex tubing, rubberized textiles and foam-backing materials, etc. Prior to forming rubber goods, latex is compounded (mixed) with various ingredients, such as antioxidants, in accordance with a specific recipe.

Latex compounding and processing steps are water-intensive processes (Cheminfo, 2013).  In addition to its use in latex recipes, water is also used in operations including:

• washing of latex containers
• floor and machinery washing
• product washing
• form/mold cleaning and form stripping operations
• direct curing
• cooling of products

These uses may generate wastewater and may result in spills and leaks from latex storage and transfer area, compounding, processing and cleaning operations. Wastewater that is not discharged to water bodies or transferred to municipal wastewater treatment plants may be disposed of using other methods. You may therefore also need to consider disposals and transfers for recycling of wastewater, solid wastes and off-spec batches that may include BENPAT or PREPOD.

Air releases

Method 1 - Monitoring and testing

If emissions are already monitored or measured under provincial or federal legislation or a municipal bylaw, those measurements must be used to report to the NPRI as they are tied directly to the conditions of process operations at the facility. If BENPAT and PREPOD are released to air as solids, the quantities released may be estimated using either the composition of the particulate matter released to air (if available) or the concentrations of BENPAT and PREPOD in the bulk material, combined with the particulate matter release quantities.

As BENPAT and PREPOD are UVCB substances, special consideration should be taken when using measurements to estimate their releases. The following approach could be used to estimate the releases of these substances based on the monitoring or measurement of their main components. This approach assumes that the main components (see Substance Information section) have similar physico-chemical proprieties, transport processes and environmental fate. It also takes into account the main source fraction of each component from the UVCB used at the facility as well as those from other sources if the facility also processes or uses these components individually or as part of other multi-constituent substances (other than BENPAT or PREPOD). For example, Diphenylamine (DPA) is considered one of the main components of PREPOD but it can also be used as a raw material for other manufactured antidegradent additives; in this case, the fraction of DPA not associated with PREPOD should not be included in the quantities of PREPOD reported to the NPRI. Use the following equation to calculate releases of BENPAT or PREPOD based on measurements of their components:

M_i = (A_ij x F_ij) / X_ij

• M_i: quantity of substance i released per year, in kg (i= BENPAT or PREPOD)
• A_ij: monitored or measured quantity of the component j present in the substance i, in kg per year
• f_ij: source fraction of component j from the substance i
• x_ij: fraction of the component j present in the substance i

If measurement of more than one main component is performed, the calculated released quantity of BENPAT or PREPOD can be based on:

• the component that is subject to the existing Canadian federal regulatory requirements (Regulatory and non-regulatory instruments)
• existing provincial or By-Laws permitting like Ontario ECA, etc.
• the average calculated quantity M_i (See note below)
• the largest volatile or least volatile component respectively for gas sampling or particulate matter analysis.

Note:

When the difference between the calculated maximum M_i and minimum M_i is above 20%, the estimation of M_i should be based on the last bullet by using the largest volatile or least volatile component respectively for gas sampling or particulate matter analysis;

When performing this type of calculation, it is important to take into consideration the precision and the accuracy of the analytical method used for each component as they will potentially have an impact on the calculated release quantities for BENPAT or PREPOD.

The information about the BENPAT and PREPOD composition can be retrieved from their SDS. Furthermore, the following links may contain more information on the composition of these substances:

Final Screening Assessment for BENPAT

ECHA Substance Infocard: BENPAT

Final Screening Assessment for PREPOD

ECHA Substance Infocard: PREPOD

For guidance on how to report data which is based on concentration(s) that fall below the method detection limit (MDL), please refer to the Guide for reporting to the NPRI.

Method 2 - emission factors

In the absence of information for the above method, facilities may use an emission factor of 0.05% (if applicable). This is a conservative, uncontrolled emission factor for releases to air from processing/industrial use which is based on the EU TGD A-Tables (European Union, 2003). This factor was used for the tire and general rubber goods generic exposure scenario (ETRMA, 2010; OECD 2004) for anti-ageing and anti-flex cracking/anti-degradant substances with a Vapor Pressure below 1 Pascal and a Boiling Point above 300 ⁰C. This emission factor is used by applying it in the following equation:

E = EF / 100 * Q * (1 - CE/100) * CF

• E: Release (release) of BENPAT or PREPOD in kg per year
• Q: Quantity of BENPAT or PREPOD manufactured in tonnes per year
• EF: 0.001, kg of BENPAT or PREPOD released respectively per kg of BENPAT or PREPOD manufactured
• CE: Control efficiency of the wastewater pollution control device, %
• CF: Conversion factor, 1000 kg per tonne

Water releases and transfers to municipal wastewater treatment plants

Method  1 - monitoring and testing

As discussed above, wastewater may be generated in the manufacturing of tire and rubber products . This wastewater may be treated on site and discharged directly to water bodies or discharged to a municipal sewer system. If releases are already monitored or measured under provincial or federal legislation or a municipal bylaw, those measurements must be used to report to the NPRI.

As BENPAT and PREPOD are UVCB substances, special consideration should be taken when using measurements to estimate their releases. The following approach could be used to estimate the releases of these substances based on the monitoring or measurement of their main components. This approach assumes that the main components (see Substance Information section) have similar physico-chemical proprieties, transport processes and environmental fate. It also takes into account the main source fraction of each component from the UVCB used at the facility as well as those from other sources if the facility also processes or uses these components individually or as part of other multi-constituent substances (other than BENPAT or PREPOD). For example, Diphenylamine (DPA) is considered one of the main components of PREPOD but it can also be used as a raw material for other antidegradent additives; in this case, the fraction of DPA not associated with PREPOD should not be included in the quantities of PREPOD reported to the NPRI. Use the following equation to calculate releases of BENPAT or PREPOD based on measurements of their components:

M_i = [(Q * C_ij * F_ij) / x_ij] * CF

• M_i: Quantity of substance i released per year, in kg (i= BENPAT or PREPOD)
• Q: Annual flow of wastewater at a given sample collection point of the facility (e.g. final discharge point for the facility effluent or other appropriate process point inside the facility) in m³ per year
• C_ij: Monitored or measured concentration of the component j present in the releases of substance i, in μg/L
• f_ij: Source fraction of component j from the substance i
• x_ij: Fraction of the component j present in the substance i
• CF: Conversion factor = 1 x 10^-9 kg/μg x 10³ L/m³

If measurement of more than one main component is performed, the calculated release quantity of BENPAT or PREPOD can be based on:

• the component that is subject to the existing Canadian federal regulatory requirements (Regulatory and non-regulatory instruments)
• existing provincial or By-Laws permitting such as Ontario ECA, etc.
• the average calculated quantity M_i (See note below)
• the component with the largest solubility

Note:

When the difference between the calculated maximum M_i and minimum M_i is above 20%, the estimation of Mi should be based on the last bullet by using the component with the largest solubility;

When performing this type of calculation, it is important to take in consideration the precision and the accuracy of the analytical method used for each component as they will potentially have an impact on the calculated release quantities for BENPAT or PREPOD.

The information about the BENPAT and PREPOD composition can be retrieved from their MSDS. Furthermore, the following links may contain more information on the composition of these substances:

Final Screening Assessment for BENPAT

ECHA Substance Infocard: BENPAT

Final Screening Assessment for PREPOD

ECHA Substance Infocard: PREPOD

For guidance on how to report data which is based on concentration(s) that fall below the method detection limit (MDL), please refer to the Guide for reporting to the NPRI.

Facilities subject to the PREPOD pollution prevention planning notice are requested to perform sampling and analysis of the PREPOD component diisopropyldimethylacridan (DIPDMA), which serves as an indicator of PREPOD presence. These facilities should use the results of this sampling to estimate the quantity of PREPOD released to water bodies or transferred to municipal sewage treatment plants.

Sampling should be performed in accordance with generally accepted standards of good scientific practice at the time of the sampling event. The following guidance document is to provide practical advice to facility operators on the sampling of industrial wastewater effluents for PREPOD and can be used for BENPAT sampling too: Guide for sampling for reaction products of 2-propanone with diphenylamine (PREPOD, CAS RN 68412-48-6) in industrial effluents.  As described in the guidance document, samples may be submitted to the ECCC National Laboratory for Environmental Testing for analysis.

Method 2 - emissions factors

A) Tire and solid robber products manufacturing

In the absence of information for the above methods, the facility may use the emission factors in table to estimate releases to water. These are conservative, uncontrolled emission factors for releases from tire and rubber products formulation and processing activities (ETRMA, 2010) derived for anti-ageing and anti-flex cracking/anti-degradants.

These emission factors are used by applying them in the following equation:

E = EF / 100 * Q * (1 - CE/100) * CF

• E: Release (release) of BENPAT or PREPOD in kg per year
• Q: Quantity of BENPAT or PREPOD manufactured in tonnes per year
• EF: 0.001, kg of BENPAT or PREPOD released respectively per kg of BENPAT or PREPOD manufactured
• CE: Control efficiency of the wastewater pollution control device, %
• CF: Conversion factor, 1000 kg per tonne

B) Latex rubber products manufacturing

Latex compounding and processing steps are water-intensive processes. In the absence of monitoring data, site specific emission factors or appropriate published emission factors, facilities may use an uncontrolled emission factor of 0.3%. This emission factor was reported by ETRMA (2010) as the 90^th percentile estimate for water releases from small or moderate scale rubber formulation and processing activities that use less than 100 tonnes per year of a substance and do not have pre-treatment (i.e. oil water separation or mechanical treatment). This emission factor is used by applying it in the following equation:

E = EF / 100 * Q * (1 - CE/100) * CF

• E: Release (release) of BENPAT or PREPOD in kg per year
• Q: Quantity of BENPAT or PREPOD manufactured in tonnes per year
• EF: 0.001, kg of BENPAT or PREPOD released respectively per kg of BENPAT or PREPOD manufactured
• CE: Control efficiency of the wastewater pollution control device, %
• CF: Conversion factor, 1000 kg per tonne

Disposals and transfers for recycling or treatment prior to final disposal

If one or more components of BENPAT and PREPOD are already monitored or measured (e.g. in sludge,  or transferred waste) under provincial or federal legislation or a municipal bylaw, those measurements must be used to report to the NPRI. The approaches described in the previous section should be followed to estimate the effective quantities of BENPAT and PREPOD that end up in disposals or transfers for recycling or treatment before final disposal.

In the absence of monitoring or measurement data, a mass balance can be used to estimate the quantity of BENPAT and PREPOD in wastewater sludge and biosolids or in generated waste. The mass balance would be based on the quantity used and the quantities released to air and water.

The tire and rubber products manufacturing facilities may generate other wastes (specifically scorched rubber, off-speciation rubber products and trimmed material from the finished product). These solid wastes, along with spent packaging, drums and other containers, may contain BENPAT and PREPOD. You may need to consider quantities of NPRI substances when these wastes and spent packaging are disposed of or transferred for recycling or treatment before final disposal.

Cheminfo (2013) Rubber Products Manufacturing Sector Study: Sector Overview, Pollution Prevention Practices and Pollution Control Measures. Internal study prepared for ECCC by Cheminfo Service Inc., Canada.

ECHA (2020a). Registered substances database; search results for CAS RNs 68953-84-4, ECHA Substance Infocard - BENPAT, European Chemicals Agency, Helsinki, Finland.

ECHA (2020b). Registered substances database; search results for CAS RNs 68412-48-6, ECHA Substance Infocard: PREPOD, European Chemicals Agency, Helsinki, Finland.

ECCC (2011a) Screening Assessment for the Challenge, 4-Benzenediamine, N,N’-mixed Phenyl and tolyl derivatives and 1,4-Benzenediamine, N,N`-mixed tolyl and xylyl derivatives, Chemical Abstracts Service Registry Number 68953-84-4 and 68478-45-5, Environment Canada and Health Canada, September 2011.

ECCC (2011b) Screening Assessment for the Challenge, 2-Propanone, reaction products with diphenylamine, Chemical Abstracts Service Registry Number 68412-48-6, Environment Canada and Health Canada, September 2011.

ETRMA (2010) Tyre and general rubber goods generic exposure scenario; Emission factor guidance for formulation and industrial use. Version 2: European Tyre and Rubber Manufacturers' Association, Brussels, Belgium.

European Union (2003) Technical Guidance Document for Risk Assessment (TGD), European

Commission, Joint Research Center

OECD (2004) Emission Scenario Document on additives in Rubber industry: OECD Environmental Directorate, Environmental Health and Safety Division. ENV/JM/EEA(2004)11, JT00166913, Paris, France.

NPI (1999) Emission Estimation Technique Manual for Organic Chemical Processing Industries: National Pollutant Inventory, Australia.

USEPA (2005) Profile of the Rubber and Plastics Industry 2nd Edition, Profile of the Rubber and Plastics Industry 2^nd Edition, EPA Office of Compliance Sector Notebook Project, February 2005, USA.

USEPA (1997) Chapter 16 - Methods for Estimating Air Emissions from Chemical Manufacturing Facilities,  Volume 2:  Point Sources Emissions Inventory Improvement Program (EIIP), USA.

Zi-Feng Zhang, Xue Zhang, Ed Sverko, Christopher H. Marvin, Karl J. Jobst, Shirley Anne Smyth, and Yi-Fan Li (2020) Determination of Diphenylamine Antioxidants in Wastewater/Biosolids and Sediment, Environmental Science & Technology Letters 2020 7(2),102-110