EnviroMail 126 Australia - Total Organic Fluorine (TOF) Compliance
ALS recently announced new testing capabilities for the analysis Total Organic Fluorine (TOF).
The initial aim of providing TOF analysis was to service the waste disposal industry in Queensland, more specifically the ERA 60 guideline values for landfill leachate and the total allowable contaminant levels in soils used as cover material.
ERA 60 Waste Disposal Limits for TOF
The ERA 60 guideline limits are provided below together with the current ALS limits of reporting (LOR). ALS LORs provide a considerable safety margin to ensure compliance with the stated limits for soils and landfill leachate not reused on or offsite. ALS is working to refine methodology to provide lower limits of reporting to also meet the limit for reuse of landfill leachate (0.0003mg/L).
MCL mg/kg) | ALS LOR (mg/kg) | |
TFOC (not including PFOS and PFOA | 10 | 1 |
Maximum total contaminant levels in soils as cover material
Clay lined (mg/L) | MCL Double lined (mg/L) | ALS LOR (mg/L) | |
TFOC (not reused on/off site) | 0.05 | 0.05 | |
TFOC (reused on/off site) | 0.0003 | 0.0003 | In development |
Allowable Leaching Contaminant Levels
Note, ERA 60 uses the term Total Fluorinated Organic Compounds (TFOC). This is equivalent to Total Organic Fluorine (TOF), noting that the concentration for TOF is expressed as fluorine.
ERA 60 Waste Disposal Limits for PFOS & PFOA
For soils used as cover material, the guideline includes separate limits for Perfluorooctane sulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA), with the TFOC limit excluding contribution from PFOS and PFOA. Targeted analysis of PFOS and PFOA (by ALS method EP231) would typically be required to meet these criteria (see below).
MCL (mg/kg) | ALS EP231 LOR (mg/kg) | |
Perfluorooctane sulfonic acid (PFOS) | 6 | 0.0002 |
Perfluorooctanoic acid (PFOA) | 16 | 0.0002 |
Maximum total contaminant levels in soils as cover material
TOF as a Screen for PFOS & PFOA
There is however opportunity to use the TOF result alone as a screening measure for the soil limits without the need to specifically analyse for PFOS and PFOA. This approach takes the conservative
assumption that all of the organic fluorine measured is present as either PFOS or PFOA. As PFOS has the lower guideline limit, this would form the determining factor in this screening approach. A
TOF concentration greater than 3.88 mg/kg would be required to produce an equivalent PFOS concentration above the 6mg/kg limit.
See examples provided below. This screening approach provides an economical option, where direct analysis of PFOS and PFOA may not be required.
Table 1: ERA 60 Waste Disposal – TOF as screen for PFOS & PFOA examples
Analyte | Units | ERA 60 limit | Sample 1 | Sample 2 | Sample 3 |
TOF | mg/kg | 10 | 2.0 | 4.1 | 12.4 |
TOF as PFOS | mg/kg | 6 | 3.1 | 6.3 | 19.2 |
TOF as PFOA | mg/kg | 16 | 2.9 | 6.0 | 18.0 |
- Direct PFOS and PFOA analysis may be warranted for Samples 2 and 3 to confirm whether PFOS/PFOA are actually present at concentrations that exceed the limits.
- Measurement Uncertainty (MU) should always be considered when comparing data against guideline limits.
ALS Packages for ERA 60 – Soils
ALS offers two packages to accommodate the scenarios detailed above; a comprehensive suite which includes analysis of TOF as well as direct analysis of PFOS and PFOA (by ALS method EP231); and a basic suite which includes TOF analysis with stoichiometric conversion of the TOF concentration to PFOS and PFOA. Refer to example reports below. In order for the appropriate parameters to be reported, the chain-of-custody (COC) must state that sample analysis is for compliance against the ERA 60 guideline. If a particular package is not requested, the comprehensive suite will be provided as default.
ALS Method Code
EP040
Sampling containers
Water/AFFF Product
60mL HDPE plastic bottle (Unpreserved), grey label
Soil/Sediment
200mL HDPE plastic specimen jar (Unpreserved), grey label
Note – for soils/sediments, the same specimen jar can be used for both PFAS and TOF analysis. A separate 60mL bottle is required for waters if also testing for PFAS.
Holding time
28 days
NATA accreditation
Pending
References
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