Guidelines for ash sampling and analysis

Question 1

1. Introduction

Accepted Answer

Solid residues are formed by incineration, co-incineration and some combustion processes. They may also be captured in dust abatement controls. Examples of industrial residues include:

incinerator bottom ash (IBA)
air pollution control (APC) residues
cement kiln dust
other bottom ash, such as meat and bone meal (MBM) and poultry litter ash
furnace bottom ash

Following this guidance will help you make sure that samples of solid residues taken for analysis:

are as representative as possible to minimise sampling bias
have consistent treatment to make sure you can compare analytical results
are collected in a traceable manner

We based this guidance on EN 14899 Characterisation of waste – Sampling of waste materials – Framework for the preparation and application of a sampling plan. It will help you decide:

how much sample to take
how often to take a sample
how to analyse the sample

The path taken will be dependent upon the aim of the sampling exercise. It will be specific to individual sites.

You can find practical guidance on how to apply EN 14899 in these supporting technical reports:

CEN/TR 15310-1 – Guidance on selection and application of criteria for sampling under various conditions
CEN/TR 15310-2 – Guidance on sampling techniques
CEN/TR 15310-3 – Guidance on procedures for sub-sampling in the field
CEN/TR 15310-4 – Guidance on the procedures for sample packing, storage, preservation, transport, and delivery
CEN/TR 15310-5 – Guidance on the process of defining the sampling plan

Residues that you produce from incineration and co-incineration plants must undergo several physical and chemical tests to demonstrate compliance with plant operating conditions, re-use, or disposal criteria.

Incineration sites permitted to incinerate animal remains may have additional waste residue testing requirements.

Question 2

2. Sampling methodology

Accepted Answer

This guidance is based on EN 14899, which describes the following steps:

define the sampling plan
take the sample in accordance with the sampling plan
transport the sample to the laboratory
prepare the test portion
extraction
analyse the sample
produce the overall report

Question 3

3. Defining the sampling plan

Accepted Answer

The sampling plan is a written record of why you sample. It describes the overall aims and includes:

specific and practical instructions on what you are going to sample
how you are going to sample
how the sample is going to be tested and by whom

Sampling plan development consists of several steps. This is an iterative process. As you proceed through each step you will obtain more information, so the sampling plan will probably require review and refinement.

If there is more than one objective, there may be a need for a different sampling plan for each objective.

In practice, you may develop generic sampling plans to serve a common objective. Depending on the objective, this may encourage consistency for sampling or analytical requirements. However, you should review generic sampling plans, adapting them to meet site-specific situations, such as on-site health and safety considerations.

Section 13 reproduces the ash sampling protocol developed by us for those incinerators permitted to burn suspected bovine spongiform encephalopathy (BSE) cattle. The protocol is highly prescriptive but may not be suitable for all incinerator types.

The next sub-sections describe each of the steps to develop a sampling plan, and sources of additional information.

3.1 Identify involved parties

There may be several parties who can contribute towards achieving the overall objective. Legislation places the responsibility on the waste producer and waste manager to characterise waste residues, often by their sampling and analysis. The waste producer will lead the process of defining the sampling plan, in consultation with other interested parties (for example, the regulator, the sampler, the analyst and the waste manager).

3.2 Identify objectives and define technical goals

The objectives define the purpose of the sampling exercise. Example objectives may include to:

comply with the sampling and monitoring requirements of an environmental permit
determine the re-usability of the material
carry out a risk assessment perhaps for human health or the environment
demonstrate compliance with quality protocols
classify a waste and determine if it is a hazardous waste

The waste producer, in consultation with involved parties, will translate the objective into clear technical goals. The technical goals relate to other elements of the sampling plan:

constituents tested for
the population that the sampling results represents
the statistical parameter determined
sampling approach (probabilistic or judgemental)
the sampling technique and any sample pre-treatment

Example of an objective translated into a technical goal:

Objective: to demonstrate that relevant measurands in ash derived from incineration processes comply with the permit.

Technical goal: take a representative sample of IBA from storage bay 1 to on the first day of each month and submit it to the laboratory for soluble metal analysis

Defining the population, assessing spatial and temporal variability and defining the scale are essential in determining how much material and how often to sample. This guidance document provides an overview but cannot reproduce the depth of guidance given elsewhere. You should refer to CEN/TR 15310 part 1 and CEN/TR 15310 part 5 for additional guidance.

The population is a statistical term used to define the total volume of material you need information on through sampling. An example of defining populations is:

population: all the ash produced by an industrial plant
annual sub-population: all the ash produced by an industrial plant in a year
monthly sub-population: all the ash produced by an industrial plant in a month

Using the previous example, and depending on the rate of production, it may not be possible or practical to wait an entire year for sampling of all the ash. Therefore, the realistic population to sample may be all the ash produced in a month. This assumes that a month’s ash production is representative of the whole year’s ash production and that there are no process variations.

Variability in the production process, for example using different waste derived fuels in an incinerator, may lead to a heterogeneous ash. You will need to take more samples to determine how heterogeneous the ash is.

The scale is the minimum quantity (mass or volume) of material below which variations are unimportant. For example, the characteristics of incinerator bottom ash from a municipal waste incinerator may vary daily because of waste collections from different areas. However, these variations may smooth out over a week and therefore between weeks. If process variations on a weekly basis are unimportant then the scale is weekly. If daily variations are important, then the scale is daily.

3.3 Determine generic level of test required

You will determine the robustness of the sampling depending on the objective and the level of sampling required.

If the sampling objective is waste classification, you should refer to Appendix D of technical guidance WM3.

The levels of testing are given in these examples:

characterisation, basic or level 1: characterisation of ash, involving extensive sampling and analysis
compliance, periodic or level 2: sampling to show compliance of a particular measurand – this requires robust sampling to give a composite sample with a lesser level of analysis
verification, quick check, or level 3: equivalent of a quick on-site test to indicate the presence or absence of a particular measurand

3.4 Identify constituents you need to test

The constituents you need to test for will depend on the objective of the sampling plan. It may be necessary to identify physical (particle size distribution), chemical (pH, specific elements) and biological parameters depending upon the nature of the original material and the intended end use, such as disposal or recycling. Legislation may also determine what constituents you need to test for.

For other compliance testing, you may find target constituents specified in legislation through environmental permits.

3.5 Research background information on waste

Use knowledge of the process or activity that produced the waste, as well as the results from previous testing, to inform the decision-making process. See these examples:

Example 1: interested parties agreed that there is sufficient evidence to conclude that a particular measurand will not be present in the waste. They agreed not to test for that measurand. The sampling plan will document the justification for removing the testing of the measurand from the analytical suite.

Example 2: results from previous tests show the heterogeneous nature of the waste. You will need to take a larger number of samples.

Background information may also include:

the inputs that created the waste
the method of ash collection
how the ash is stored (is it stockpiled in heaps or in a container?)
how much ash is stored and where it is stored
whether the solid waste is a moving or static stream
any access issues that may affect sampling
whether the ash is heterogeneous, homogeneous, granular, or monolithic (formed from a solid block)

3.6 Identify health and safety precautions

Health and safety should have the highest priority.

For some industry-wide sampling objectives, details of levels of testing and components to be tested can be agreed at a generic level. However, generic sampling plans are unlikely to provide details of site-specific safety hazards and risk assessment.

The site operator has the duty of care for health and safety for their site.

Prior to undertaking site work, you shall carry out a risk assessment.

BS ISO 18400-103 Soil quality – Sampling – Part 3: Guidance on safety for identifying potential hazards is a useful reference. Material safety data sheets are also useful sources of information if you know the constituents of the materials.

The risk assessment should be regularly reviewed. You must follow site safety rules and safety procedures.

3.7 Select sampling approach

The decisions that you make at this point in the process (and in section 3.8) will determine how statistically representative your final sample will be.

Your sampling approach will depend on the sampling objective. You should consider practical matters, such as the physical characteristics of the residue and the risk assessment.

Probabilistic or judgemental sampling

The choice of whether to take a probabilistic or judgemental approach considers the variability within the sub-population and the acceptable (or agreed) degree of uncertainty. Probabilistic sampling provides greater confidence over judgemental sampling in that the obtained sample represents the whole population. Probabilistic sampling is the approach the Environment Agency prefers.

There may be practical, including safety, and financial constraints that preclude this approach. For example, IBA from clinical waste may contain a mixture of free-flowing ash and fused lumps of material. In this situation it will not be possible to take a sample that is representative of the whole population; a judgemental approach will be the only practical approach. Judgemental sampling can also be useful to address a specific question, such as to identity a specific piece of material present in the waste.

If you choose a judgemental sampling approach, then sampling of the sub-population should be as representative as possible.

You can find more information on these approaches in CEN/TR 15310-1.

The choice of approach taken will be site specific but whichever approach you take; you must justify it and record the justification in the sampling plan.

The sampling approach will also decide:

how much sample to take
whether you take individual or composite samples
where to take the sample from

Determine the increment and sample size

The actual size of the increments and samples will depend on the quantity of material required by the laboratory for analysis. It is advisable to consult with the analytical laboratory to make sure that you provide sufficient but not excessive quantity of material to them. Sending too small an amount will mean that there is insufficient quantity to complete the analysis; sending too much may have storage and cost implications. Depending upon the objective, you may also wish to consider if you need duplicate samples.

An increment is the amount of material (mass or volume) obtained through a single sampling action. You may combine it with other increments to form a composite sample. If you get individual increments analysed separately, each increment will be an individual sample.

The minimum increment size is governed by the need for the sampling device to accommodate all particle sizes. The device opening should be at least 3 times the diameter of the largest particles.

The minimum sample size must consider the homogeneity of the individual particles, so that you take a representative sample. Where residues are large, fused lumps of material (such as clinker-like lumps of metal items, glass and ash from clinical waste incinerators), you will need a larger sample size. This will make sure that, after particle size reduction (see section 3.8), there is sufficient sample for analysis of the ash.

The use of composite or individual samples

The choice of whether to obtain composite or individual samples depends on the following objectives:

Characterisation, basic or level 1 testing: to obtain a reliable estimate on the variability of individual components within the ash, take a substantial number of samples.

Compliance, periodic or level 2 testing: to obtain a reliable estimate on the mean quality of the ash over a period, take a substantial number of increments over time to form 1 or several composite samples. For this level of testing, it will be useful to have a diagram showing the areas where you should take the increments of ash. By defining a methodological approach to sampling, you can take future samples in a similar manner, so that you can compare results.

Verification, quick-check or level 3 testing: one sample or small number of samples to give an approximate indication of the quality of the material.

Determine the number of increments and samples

The number of increments that will form the composite sample is dependent on the variability of the ash, as well as the overall sampling confidence and precision required. In other words, taking a 1kg spot sample from a 1 tonne stockpile, would not give a high degree of confidence in the analytical result.

CEN/TR 15310-1 and technical guidance WM3 describe detailed statistical approaches to determine the number and the size of samples and increments. EN 932-1 Tests for general properties of aggregates Part 1 – Methods for sampling, gives a simpler calculation for determining the mass of sample. Also, use EN 932-1 to check if the number of sampling increments is adequate.

3.8 Identify most appropriate sampling technique to address sampling requirements

You should choose the sampling technique and equipment that is appropriate for your site and that will meet the sampling objective. Document your choice in the sampling plan.

CEN/TR 15310-2 provides guidance in the selection of appropriate sampling techniques and equipment that is most relevant to solid waste residues sampling.

The choice of sampling technique is dependent on:

the type of material (for example, solid material)
where you take the sample from (for example, a stockpile or conveyor belt)
how well mixed the component of interest is
the level of testing

Your choice of sampling equipment depends on several factors, such as:

the nature of the waste
how much sample you require
where you take the sample from

The equipment must be safe, practical and fit-for-purpose. For ash sampling, the most likely types of equipment are scoops or trowels. CEN/TR 15310-2 describes each of the sampling equipment types.

CEN/TR 15310-2 contains information on sampling ash from hoppers, heaps, silos, bags, kegs or drums. To do this sampling, you must gain safe access to the material. After transferring the material to the sample container, wipe the container and label it according to the sampling plan. The composite sample may be of considerable mass, so you may need to reduce its size to aid transportation to the laboratory. If you need to sub-sample, make sure you protect the integrity of the sample by:

carrying out sub-sampling in a clean protected area, using clean equipment to avoid contamination of the sample
only doing sub-sampling in the field if you can produce a homogeneous sample
mixing the sample before taking the sub-sample – for ash, first form a conical heap, then shovel or scoop the material from the bottom of the heap to the top, repeat this action at least 20 times

The final sample must be representative of the field sample and representative of the stockpile.

CEN/TR TR-15310-3 describes the techniques for sample size reduction, which are dependent on the sample mass.

Particle size reduction

Depending on the nature of the analysis you need to do, you may need to reduce the particle size of the sample. In these circumstances remove all items that would interfere with particle size reduction from the sample (for example metal, cans, and bricks). Record the weight of the items removed, so that the analytical result is for the total mass of sample taken and not just the fraction analysed. If, after manual particle size reduction, there is insufficient sample available for analysis, you may need more sample to add to the first sample. You could treat this as 2 bulk increments (see CEN/TR 15310-3).

Question 4

4. Taking the sample in accordance with the sampling plan

Accepted Answer

Take samples in accordance with the sampling plan. Document any deviations from the sampling plan on the sampling record. An example of a sampling record is in section 11.

Record observations made during the sampling. These can be useful when interpreting the results. Examples of the type of observations include:

details of incinerator loading and process type
type of waste relative to the ash sample
odours

Question 5

5. Transporting the sample to the laboratory

Accepted Answer

Duty of care requirements apply to everyone involved in handling waste, including waste samples taken for analysis. You may be able to register for a D5 waste exemption if you meet the specified criteria for transporting waste samples for testing or analysis.

Transport samples in a manner that does not cause deterioration. It is advisable to check with the analytical laboratory that the packaging, transportation and storage procedures are appropriate to protect the integrity of the sample. CEN/TR 14310-4 provides guidance on sample packaging, storage, preservation, transport, and delivery. Document the procedures you use in the sampling plan.

5.1 Packaging and labels

You should make sure that the opening of your container for samples is of an appropriate size to pack the sample material. You must pack the samples to protect them from:

potential reactions with the packaging
light
deterioration (for example, through moisture loss or gain)
contamination

The packaging should be of suitable size for transportation and reception by the analytical laboratory.

Analytical laboratories should be able to provide advice on requirements recommended for designated tests. For example, EN 1519 gives a list of recommendations for the packaging, transport and storage requirements for samples destined for loss on ignition tests. Key recommendations are:

an airtight container of amber glass or plastic with no migration of constituents, for example polypropylene or polyethylene
transport in dark and cool conditions

Mark all sample containers with a unique identifier that is recognisable to the sampler and the analytical laboratory. Do this in the manner identified in the sampling plan. Complete a chain of custody form (see example in EN 14899) for each sample and send with the sample to the analytical laboratory.

5.2 Preservation

Depending on the nature of the material, minimise the time between sampling and analysis to avoid deterioration or contamination of the sample. It is advisable to discuss and agree the requirements with the analytical laboratory before sampling.

Question 6

6. Overview of analytical methods

Accepted Answer

The analytical methods and the level of uncertainty for the measurands required depend on the objectives of the sampling plan. This section provides an overview of measurands for various purposes.

When the objective of sampling is for characterisation or compliance purposes, the analytical laboratory should have accreditation from the United Kingdom Accreditation Service (UKAS) to EN ISO/IEC 17025 ‘General requirements for the competence of testing and calibration laboratories’ for the scope of the work.

When the objective of sampling is to classify the waste under the List of wastes, through assessment of whether or not it is a hazardous waste, then the approach must be consistent with that set out in technical guidance WM3.

6.1 Preparation of laboratory sample

The sampling plan documents the details for taking a representative sample and transporting that sample to the laboratory. The laboratory needs to prepare test portions for analysis that are representative of the field sample.

You should follow EN 15002 Preparation of test portions from the laboratory sample, to obtain suitable test portions for most analytical procedures. EN 14735 Preparation of waste samples for ecotoxicity tests, describes the necessary preparatory steps, specific to carrying out ecotoxicity tests on wastes.

Analytical procedures may define the number and size of the test portions and how to preserve them. Analytical procedures may also define requirements for drying or particle size reduction. For example, leaching behaviour test EN 12457-3 uses test material with a particle size below 4mm, achieved initially by sieving and then, if necessary, by crushing. Compositional analysis using EN 15309 uses a dried sample.

You can find guidance on the choice of sample treatment techniques (such as drying, phase and fraction separations and particle size reduction) in EN 15002. It provides details on when to use a particular technique, as well as when not to use it. Further information on requirements for test portions from aqueous and solid laboratory samples are in EN 15002.

6.2 Analytical methods

If the test and analytical standard is not dictated by legislation, then use the standards in the following order of priority:

Comité Européen de Normalisation (CEN)
International Standardisation Organisation (ISO)
national standards

For the assessment of hazardous properties, you can find guidance on how to assess a waste and analytical methods in technical guidance WM3.

An analytical laboratory will be able to give advice on which analytical and test methods will meet the sampling objective.

Question 7

7. Sample records

Accepted Answer

To have traceability there must be records and documentation. All documentation must be traceable to the sampling plan.

EN 14899 lists the following documents and provides examples:

sampling plan – the instructions on how the take the sample, completed by the waste producer in consultation with interested parties
sampling record – a record of changes to the agreed sampling plan, completed by the sampler
Chain of Custody form – completed by the sampler
sample analysis request form – completed by the sampler

Test reports must contain details of sample preparation as well as the reference to the sampling plan.

In addition to test results, the test report must include at least the following information:

a description and identification of the laboratory sample
the processes, procedures, and apparatus used
results of the determination expressed in the appropriate units
any details not specified in the standard, or which are optional, and any other factors which may have affected the results
date of receipt of the laboratory sample and dates when you carried out the test
reference to the standard or procedure followed

Samples of waste are subject to duty of care and, where relevant, hazardous waste controls when transferred, moved, or received.

Question 8

8. Requirements of a sampling plan

Accepted Answer

A sampling plan should contain the following information.

Sampling plan reference:

General information:

sampling plan completed by
on behalf of
involved parties:
- project manager and waste producer
- end user
- regulator
- analyst
name of sampling operative
name of company doing the sampling

Sampling objectives and technical goals:

identify sampling objectives
define technical goals

Location:

address of sampling location
source and origin of material

Generic level of testing required:

Sampling approach (with justification) – probabilistic or judgemental:

sampling approach
justification

Material:

process or activity producing the material
causes of variability (spatial and temporal) in the waste stream (assists judgement of population and sub-set to sample)

Analytical laboratory:

company details
contact

Analysis required:

identify target constituents you wish to test for and appropriate limit of detection

Specific material:

type of material
relevant characteristics
relevant tests and duplicates

Access, health, and safety:

identify any access problems or restrictions that may affect the sampling programme
identify health and safety precautions (see ISO 10381-3 Soil quality. Sampling. Guidance on safety)

Sampling methodology:

specify methodology
specify sampling pattern
define place and point of sampling
specify detailed sampling location (that is specific stockpile including description of site location, stockpile reference number and product type)
specify period of production (that is waste produced over specified period at this location) to define population (that is the dates stockpile started and completed)
define population and sub-population (volume) to be sampled (that is stockpile size sampled)
specify persons (that is witnesses) to be present (include name and address); also record details on chain of custody documentation
specify use of individual or composite samples
identify equipment
specify number of increments and samples to collect (see CEN/TR 15310-1)
specify increment size and sample size (see CEN/TR 15310-1)
specify any provisions made for replicate samples
specify any requirements for sample reduction
detail requirements for on-site determinations
identify sample coding methodology
identify safety precautions
identify anticipated restrictions or limitations that may impact on reliability of data

Sub-sampling:

detail procedure (see CEN/TR 15310-3)

Packaging, preservation, storage, transport requirements (CEN/TR 15310-4):

packaging (size; shape; material considering risk of adsorption and reaction; cleaning)
preservation (you must pack and transport samples in such a way to preserve their condition at the time of sampling)
storage
transport (complete a chain of custody form and send with each sample)
delivery date

Question 9

9. Field sampling techniques (1) sampling powders, granules, and small granules

Accepted Answer

This section covers probabilistic and judgemental sampling for powders, granules, and small granules.

9.1 Sampling small static volumes from hoppers, heaps, and silos

Probabilistic sampling using a core sampler:

using a core sampler to cut out the required shape and amount of material as per the sampling plan
place the sample in a sample container

Judgemental sampling using a scoop:

dip the scoop in the material at the area defined in the sampling plan
withdraw the scoop and level off the material so there is none above the sides of the scoop
transfer the sample into a sample container

9.2 Sampling large static volumes from hoppers, heaps, and silos

Probabilistic sampling using a vacuum probe or sampling auger or scoop:

push the vacuum probe, sampling auger or scoop through the material in the identified direction taking a series of individual samples until the traverse is complete
combine the individual samples to give a directional sample
transfer the sample into a sample container

Judgemental sampling using a vacuum probe or sampling auger or scoop:

push the vacuum probe, sampling auger or scoop through the material to the identified point and extract the sample as per the sampling plan
transfer the sample into a sample container

Question 10

10. Field sampling techniques (2) sampling course or lumpy materials

Accepted Answer

This section covers probabilistic and judgemental sampling for course materials.

10.1 Sampling small volumes from a bag, keg, or drum

Probabilistic sampling:

empty the material onto a clean surface
using a straight edge, make a cut into the material at the spot identified in the sampling plan
move the material to one side away from the pile
make a parallel cut into the remaining material as identified in the sampling plan
take the material between the parallel cuts to form the directional sample
transfer the sample to a sample container

Judgemental sampling:

dip the scoop in the material at the spot identified in the sampling plan
take the required sample size, as identified in the sampling plan
transfer the sample into a sample container

10.2 Sampling large stockpiles

Probabilistic sampling:

flatten out the stockpile and collect samples across the length and breadth of the material as specified in the sampling plan
place individual increments into a new pile, mix with the digger and repeat until the sample is well mixed enough to obtain a representative sample that has a small enough volume to handle manually
transfer the sample into a sample container

Judgemental sampling:

collect individual samples from the specific part of the stockpile as detailed in the sampling plan
transfer the sample into a sample container

Question 11

11. Example sampling record

Accepted Answer

This is an example sampling plan, which has been adapted from EN 14899:

Sampling plan reference:

Sample code: reflect site location, material type and date of collection

Date and time of sampling:

Signature of sampler:

Other persons present:

General information:

waste producer staff contact
client (company) staff contact
location of sampling
sampling carried out by (company)
type of sampler

Material:

type of material
estimate of moisture content
description: colour, odour, consistency, homogeneity and grain size – uniform or diverse.

Sampling methodology:

describe and define batch or consignment sampled
place and point of sampling
access problems that affected areas or volumes of material sampled
safety measures taken
describe procedure adopted
equipment used
number of increments and samples collected
increment size and sample size
observations during sampling
details of on-site determinations (if these are done, complete field records and include in sampling record)

Sub-sampling and pre-treatment:

identify location: such as on-site or fixed laboratory facility (describe whether open air or enclosed)
procedure

Packaging, preservation, storage, and transport details:

packaging
preservation
storage
transport

Deviations from sampling plan:

details

Delivery to analytical laboratory:

company
delivery date
received by
signature

Question 12

12. Analytical and leaching behaviour tests

Accepted Answer

This section lists recommended test methods.

12.1 Dry matter content

EN 14346 Calculation of dry matter by determination of dry residue or water content.

This is based on a method for drying at 105°C to constant mass.

12.2 Elemental composition

EN 15309 Determination of elemental composition by X-ray fluorescence

Describes 2 procedures: a quantitative and semi- quantitative determination of major and trace element concentrations.

12.3 Loss on ignition

EN 15169 Determination of loss on ignition in waste, sludge, and sediments.

Largely used for assessing the organic matter content. Note that:

elementary carbon or any volatilisation or chemical reaction of inorganic compounds will also be included in the loss on ignition value
whether the determination is carried out on a dry matter or not will depend on whether there is a significant amount of volatile matter or not

For some materials it may be convenient to carry out the determination of both dry residue and loss on ignition in successive operations in the same crucible.

12.4 Metals

EN 13657 Digestion for subsequent determination of aqua regia soluble portion of elements.

EN 13656 Microwave assisted digestion with hydrofluoric (HF), nitric (HNO3) and hydrochloric (HCl) acid mixture for subsequent determination of elements.

Solutions produced by these methods are suitable for analysis by:

atomic absorption spectrometry (AAS)
inductively coupled plasma emission spectrometry (ICP-OES)
inductively coupled plasma mass spectrometry (ICP-MS)

12.5 Total Dioxins

Method based on EPA 1613 Tetra- through Octa-Chlorinated Dioxins and Furans by Isotope Dilution HRGC/HRMS.

Alternative is methods based on EPA 16130 Tetra- through Octa-Chlorinated Dioxins and Furans a tandem quadrupole mass spectrometry system (GC-MS/MS).

These method gives several scenarios for extraction, analysis etc. The laboratory should use a method that is accredited to ISO 17025 by an external body such as UKAS.

Method based on BS ISO 13914.

Soil, treated biowaste, and sludge. Determination of dioxins and furans and dioxin-like polychlorinated biphenyls by gas chromatography with high resolution mass selective detection (HR GC-MS).

It is the responsibility of the user of this standard to validate the application for ash matrices.

12.6 Dioxin like PCBs

EN 15308 Characterization of waste. Determination of selected polychlorinated biphenyls (PCB) in solid waste by using capillary gas chromatography with electron capture or mass spectrometric detection.

12.7 Total organic carbon

EN 13137 Determination of total organic carbon (TOC) in waste, sludges, and sediments.

12.8 Total protein

Aqueous extraction followed by phenylisothiocyanate (PITC) derivatization and subsequent analysis by high performance liquid chromatography (HPLC).

12.9 Leaching behavior tests

EN 12457-1 One stage batch test at a liquid to solid ratio of 2 litres/kg for materials with particle size below 4mm.

EN 12457-2 One stage batch test at a liquid to solid ratio of 10 litres/kg for materials with particle size below 4mm.

EN 12457-3 (this employs a 2-stage batch test at 2 litres/kg and 8 litres/kg) for materials with particle size below 4mm.

EN 12457-4 One stage batch test a liquid solid ratio of 10 litres/kg for materials with particle size below 10mm.

CEN/TS 14405 Up flow percolation test (under specified conditions).

EN 14997 Influence of pH on leaching with continuous pH-control.

CEN/TS 15364 Acid and base neutralisation capacity test.

Question 13

13. Testing residues following incineration of suspected BSE cattle

Accepted Answer

This section is specific to the objective of testing residues following incineration of suspected BSE cattle. If your incinerator is not permitted to incinerate suspected BSE cattle, this section does not apply.

13.1 Introduction

The purpose of analysis is to confirm that the assumptions made in the risk assessment concerning releases to air are correct and that the risk from burning animal remains in incinerators are negligible. The sampling of IBA is a surrogate for the releases to air and is only carried out if sampling of the APC is not possible (for example because there is no abatement). The following is applicable:

The operator will prepare the sampling plan in accordance with these guidelines and submit the sampling plan to the regulatory officer for agreement.

13.2 Sampling objective and technical goals

The sampling plan and accompanying risk assessment will propose how sampling is to take place to meet the following objectives:

collect samples of ash in a reasonably consistent manner
obtain representative samples of ash as far as is reasonably possible by minimising sampling bias
sample preparation requirements minimise the sampling handling and preparation required by analytical laboratory staff

The technical goal is to take a representative sample from a 24 hour burn, so that you achieve compliance for the sampling regime.

13.3 Sampling frequency and analytical requirements for IBA and APC

There are 4 stages of sampling.

Stage 1

1 sample per day over a 1-week period from each incinerator (that is 7 consecutive samples).

Sampling at stage 1 should continue in subsequent weeks until results of the analyses are available, and you can assess the data. Do not make assessments on anything less than a complete week of data that has been collected in accordance with stage 1 of this protocol.

Stage 2

1 sample per week over a 1-month period from each incinerator (that is 4 consecutive samples).

Stage 3

1 sample per month for 3 months from each incinerator (that is 3 consecutive samples).

Stage 4

1 sample per quarter for 1 year from each incinerator (that is 4 consecutive samples).

If all samples meet the criteria for total protein at each stage, you may reduce the sampling frequency for the next stage. However, if at any time, samples exceed the action levels for total protein during stages 2, 3 or 4, or the regulatory officer considers it necessary, the sampling frequency should revert to the previous stage. If the failure is by more than twice that of the action level, then you must carry out a thorough investigation.

A maximum sample mass of 10g is needed.

Total organic carbon analysis is required for IBA and APC residues, and APC residues also requires protein analysis.

You must do all analysis in duplicate.

APC samples are only required if a process has an abatement plant. However, if the process does not have an abatement system with an easily accessible sample location, then you must sample IBA for protein at the frequency given for APC.

13.4 Plant loading

Make sure that the ash sample taken is representative of the specified loading rate. The regulatory officer should make sure that there is not more than one change of loading rate in any day of the commissioning period. You should collect:

at least 1 of the sets of samples from stage 1 under normal plant throughput
1 of the remaining sets of samples during maximum plant throughput
all samples at the burnout rate initially proposed by the operator – if these fail the action levels detailed in this guidance, then you will need to amend burnout time and repeat sampling

13.5 Sampling frequency and analytical requirements for dust from the stack

All samples must be taken by MCERTS certified personnel.

The sample should be a minimum mass of 50mg. However, if insufficient material is collected after 10 hours of sampling you may assume that the results of the bag filter samples are representative of the dust samples.

Sampling frequency should be:

one sample taken during stage 1
one sample taken 3 months after first sample
annual sampling thereafter

Analysis required is total protein. Do all analysis in duplicate.

13.6 Limit and action values

Table 1 gives the limit and action values for total organic carbon and protein.

Table 1: Limit and action values

Substance	Limit or action value	Preferred analytical method
Total organic carbon	3%	Remove inorganic carbon and subsequent analysis by elemental analyser
Total protein	5mg/100g sample	Phenylisothiocyanate derivatization and subsequent analysis by HPLC

13.7 Sampling requirements for IBA, APC and dust emissions from stacks

Health and safety are not covered in this guidance. You must identify health and safety requirements in a site risk assessment.

Wear gloves to minimise the risk of sample contamination when sampling IBA, APC and dust emissions from stacks.

A clean dedicated working area for sample preparation and packaging should be available, which is free from sources of contamination.

You will require an electrical or mechanical grinder, capable of milling ash to a fine powder.

Wash and dry sampling equipment after each use and stored in a clean, dedicated area.

13.8 Sampling approach – IBA

You should take several samples of ash from either the de-ashing process or from the ash receptacle. The details of the sampling should be in the site sampling plan. These samples should be discrete and representative, from a burn out period of not more than 24 hours (or another period as agreed by the regulatory officer), to give approximately 1kg of sample.

This sample is further divided by coning and quartering.

13.9 Method for coning and quartering of sample

Follow these steps to cone and quarter a sample:

Place sample in a deep, flat-bottomed tray and mix
Form into a cone then flatten until you obtain an equal shallow depth of ash
Divide this into 4 equal portions using a fine edged rod
Remove 2 diagonally opposite portions for further coning and quartering
Discard the other 2 portions
Repeat steps 1 to 3
Remove 2 diagonally opposite portions (A) and remove for particle size reduction
Mill portion A to a fine powder
Divide portion A in half
Place half in storage (retain this sample until the regulatory officer agrees you may discard it)
Divide the remaining half for analysis.

If the IBA obtained from the incineration process is already finely divided, then on agreement with the regulatory officer, you may omit steps 1 to 8.

13.10 Sampling approach – APC

A sample taken at this stage is normally finely divided, homogeneous and representative. There is no need to grind it further. Obtain a final sample by following these steps:

Divide portion A in half.
Place half in storage (retain this sample until the regulatory officer agrees you may discard it).
Divide the remaining half for analysis.

If the sample is not finely divided, take a primary sample in accordance with the site sampling plan. Then follow the process described for IBA.

13.11 Sampling approach – dust from the stack

The analysis for protein is extremely sensitive so contamination of the sample can easily occur. It is important that at all stages when handling the filters, you wear gloves and use forceps.

Adjust the sampling time so that you collect a mass of around 50mg of dust or until the filter blinds. In the case of low dust levels (that is less than 2mg/m³), sampling may take up to 10 or 12 hours.

In addition to the filter from the stack you should submit an unused filter for analysis.

If practical, collect the sample isokinetically at suitable points. In the case of low levels of dust in the stack, single point sampling should take place. The average velocity should be set to achieve near to isokinetic conditions and the sampling time extended up to 12 hours.

Filters should be of glass fibre.

Place the stack filter and control filter in separate petri dishes and dispatch for analysis.

Question 14

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