Consultation outcome

Consultation response: EALs for emissions to air second phase review

Updated 14 December 2023

1. Background

The Environment Agency uses environment assessment levels (EALs) to judge the acceptability of proposed emissions to air from industrial processes, and their relative contribution to the environment. EALs represent a pollutant concentration in ambient air at which no appreciable risks or minimal risks to human health are expected.

In December 2011, we ran a consultation to identify a new hierarchy for the derivation of EALs. We made a commitment that before introducing any new EALs, we would hold a further round of public consultation to ask for comments on proposed substance-specific levels. We would then consider the comments before adopting them.

There are currently 88 substances with EALs published in the GOV.UK guidance on air emissions risk assessment for your environmental permit. Working with the UK Health Security Agency (UKHSA, previously Public Health England), in 2020 we consulted on, and eventually published, updated or new EALs for 11 substances. On 28 March 2023, we started a formal consultation, which closed on 20 June 2023, on updated or reviewed EALs for a further 13 substances.

This response gives the results of the 2023 consultation, our feedback on the comments received, and how we will implement the new EALs.

The consultation sought the views of operators of regulated facilities, members of the general public, trade bodies, non-government organisations, and others who may be affected by implementing the new EALs. The review of the evidence for each substance and the derivation of each EAL was done in close cooperation with UKHSA. To support the public consultation, we summarised information on how we had arrived at each EAL. The proposed changes were presented in a summary table, shown as Table 1.

Table 1: Proposed changes to substance EALs

Substance	Current short-term EAL (1 hour mean) mg/m3	Current long-term EAL (annual) mg/m3	Proposed updated short-term (ST) EAL mg/m3	Proposed updated long-term (LT) EAL mg/m3
Acrylamide	0.018	0.0006	None Withdraw current EAL	0.00005 (annual) Withdraw current EAL
Butadiene	None	No EAL (UK Air Quality Standard Objective in use)	0.00225 (24 hour mean) New value	UK Air Quality Objective No change required
Cadmium	None	No EAL (Target Value already in use)	0.00003 (24 hour mean) New value	EU Target Value No change required
Chromium III	0.15	0.005	None Withdraw current EAL	0.002 (24 hour mean) Withdraw current EAL
Copper	0.2	0.01	None Withdraw current EAL	0.00005 (24-hour mean) Withdraw current EAL
Ethylene oxide	0.552	0.0184	None Withdraw current EAL	0.000002 (annual mean) Withdraw current EAL
Hydrogen chloride	0.75	None	0.75 (1-hour mean) No change required	No change
Hydrogen cyanide	0.22	None	None Withdraw current EAL	0.002 (24-hour mean) New EAL
Mercury	0.0075	0.00025	0.0006 (1-hour mean) Withdraw current EAL	0.00006 (24-hour mean) Withdraw current EAL
Methyl chloride (chloromethane)	21.0	1.05	None Withdraw current EAL	0.018 (24-hour mean) Withdraw current EAL
Methylene chloride (dichloromethane)	3.0	0.7	2.1 (24-hour mean) Withdraw current EAL	0.77 (annual mean) Withdraw current EAL
Nickel	None	No EAL (Target Value already in use)	0.0007 (1-hour mean) New value	EU Target Value No change required
Selenium	0.03	0.001	None Withdraw current EAL	0.002 (24-hour mean) Withdraw current EAL

2. How we ran the consultation

The EAL consultation document and supporting dossier were available for public consultation on GOV.UK, from 28 March to 20 June 2023. The consultation was accompanied by a consultation response form, with questions as set out in Appendix A.

We promoted the consultation by distributing over 800 emails, including:

• emails to a wide range of trade bodies who represent the industrial sectors from whom emissions of the substances with the new EALs are reported to our pollution inventory
• emails to manufacturing companies, water companies, interested third parties, academics, and non-governmental organisations whom we considered may be interested in our proposals

We also sent a targeted email reminder on 31 May 2023.

We received 8 responses to the consultation, 7 of which were submitted online during the consultation period.  The eighth response was sent directly to the consultation team and was entered onto the system. One response was anonymous but was still taken into consideration. One body responded to acknowledge the consultation but did not provide any specific comments. The respondents are listed in Appendix B.

3. Summary of main findings and actions we will take

Having considered the responses to our consultation, we are providing several clarifications on points raised and will make some additional clarifications on existing guidance.

This section summarises the responses we received to our consultation questions and provides detail on the action we will take as a result of these responses.

Q1. Which of the listed substances for which we are proposing updated EALs do you routinely use to assess the impact of your proposed emissions in support of permit applications?

We asked this question to determine the types of activities and industries that would be most affected by the proposed EAL changes. We received 4 responses for this question, principally from chemicals and manufacturing trade bodies, as well as from an organisation whose members work with a variety of industries.

The substances mentioned included: cadmium (3 respondents), chromium III, copper, mercury, nickel, and selenium (2 respondents for all of these), hydrogen chloride (2 respondents), acrylamide and methyl chloride.

Respondents mentioned that these compounds may be included in air dispersion modelling or air quality assessments from chemicals, coal, biomass or energy from waste installations, amongst others.

Our comments on responses to Question 1

We are content that we have identified substances routinely used or emitted by our stakeholders in our targeted review of EALs.

Q2. Do you expect the proposed changes to these EALs to affect your operations, and if so, how?

We received 3 responses to this question. The issues stated are summarised as follows.

Two respondents raised the concern that more stringent EALs (for example, the more stringent values for copper and methyl chloride) could have implications for operators submitting permit variations or undergoing permit reviews, by triggering additional requirements for abatement, retrofits, or fuel quality changes. The point was made therefore that EAL revisions introducing material changes should be based on robust health data.

One respondent highlighted that a number of annual mean EALs have been replaced with 24-hour mean long-term EALs, and asked the Environment Agency to advise on how operators should assess their operations against these updated long term EALs. The respondent raised the concern that modelling of short-term peak (for example, maximum 24 hour mean) concentrations is subject to greater uncertainty than modelling annual mean concentrations. Hence the change has the potential to increase uncertainty in model forecasts.

Finally, a respondent specifically focused on the potential impact of the EAL changes on Waste Gas Treatment for the Chemical Sector (WGC) UK best available techniques (BAT) requirements. Given the stringent BAT associated emission levels (BAT-AELs) set by the forthcoming UK BAT document, the Environment Agency was asked to confirm that if the BAT limits are met, the EAL requirements should also be met. This would allow sites to make longer-term investments that will meet all future requirements.

Comments were also made regarding specific substances as follows.

The new methyl chloride EAL may have implications for any ‘emergency’ or abnormal operation releases at some chemicals site, that might continue for a few hours.

The new proposed EAL for acrylamide would cause exceedance of predicted ground level concentration at a chemicals site that was modelled. Currently the site is in compliance with their current limits, and therefore raised the query about the implications of potentially exceeding the new EAL.

Our comments on responses to Question 2

We confirm that the EALs are based on the most recent and reliable toxicological data, which has been reviewed both by our specialists and by the UKHSA. We are therefore confident of the robustness of the new EAL values.

We reiterate that any proposed changes to EALs would apply to new permit applications or variations to existing permits only. Potential applicability to permit reviews would be addressed on a case-by-case basis. In the cases raised, where exceedances to the new EALs were modelled for existing facilities, we note that:

• emergency or abnormal releases from any permitted installation would need to be reported individually to the Environment Agency under the permit part A and part B reporting system
• the new acrylamide EAL would need consideration at an existing plant only at the next permit review, at which time we will again need to consider risk management on a case-by-case basis

In our 2021 EAL consultation Appendix 1, we explained that, for derivation of long-term EALs based on a threshold effect (for example, for many non-genotoxic carcinogens), the preferred averaging time is 24-hours (daily) and not an annual mean. Long-term EALs are usually based on adverse health effects observed following repeated daily exposures, often averaged, over longer time periods – weeks, months, and years. The mean daily concentration averaged over a longer duration should not exceed the long-term EAL, although some individual exceedances on a daily basis are likely over any averaged time period. The duration over which daily concentrations are averaged should reflect the nature of the activity – for example, continuous versus intermittent – and the magnitude of any observed variability from day to day. The maximum averaging period is one year, but lesser durations such as a month or 3 months may be appropriate in some circumstances. However, we do not consider it acceptable for large and regular daily exceedances for a substantial time period to be smoothed out by use of a longer than necessary averaging period for any exposure.

Short-term EALs apply to periods of exposure up to 24 hours in duration. They are based on effects observed after, at most, a few days of exposure and often relate to acute or peak exposure events. The mean concentration of a substance in any single 1-hour or 24-hour period should not exceed the short-term EAL.

For some short-term effects – either hourly or daily – then compliance with the long-term EAL also results in compliance with the short-term EAL and no short-term value is recommended.

We acknowledge the issues raised by respondents in this consultation with regards the use of a 24-hr averaging time and will explain these changes more fully within our risk assessment guidance.

With regards to the link between the BAT Atmospheric Emission Limits for Waste Gas Treatment for the Chemicals Sector and the new EAL values, the BAT-AELs represent the concentration of a compound at the emission point, generally the stack for a given facility. However, the EAL is calculated at ‘ground level’, hence is unlikely to reflect the concentration at the stack exit point, given dilution, stack height, and meteorological conditions. These will change on a case-by-case basis for each facility, and the Environment Agency cannot therefore guarantee a correlation between BAT-AEL and EALs. These will need to be checked by modelling of individual conditions for each facility.   

In situations where BAT conditions do not allow meeting the EAL for a given facility, the need for further controls will be considered, taking account of their costs and benefits, where the releases constitute a major proportion to an EAL. Any significant contribution to a breach is likely to be unacceptable but will be assessed on a case-by-case basis, taking account of the costs and benefits of the situation.

Q3. Is a long-term EAL for mercury lower than the current proposal practical for your industry and your business?  What level of reduction could be achieved by implementation of best available techniques for emissions abatement? 

We included this question as we recognise the much lower EAL value now assigned to mercury. We received 3 responses to this question.

One respondent mentioned that their industry sector is already implementing a number of measures to decrease mercury emissions from operational stacks. However, the sector does not have information on the overall reduction in mercury emissions that these techniques could achieve and whether the reduction would be enough to meet the new EAL. Hence it is recommended that the Environment Agency conduct a full impact assessment to determine if EALs can be met before they are introduced.

A second respondent highlighted that the significant reduction in the long-term EAL for mercury can be expected to have implications for relevant industrial process operators. The respondent also highlighted that the most recent (2013) data on annual mean concentrations of mercury in the UK was 0.00045 µg/m³ and that, given this low level, a reduction in long-term EAL from 0.25 to 0.06 µg/m³ was not expected to result in a change in the status of baseline conditions for mercury.

Finally, a third responded highlighted that emissions from large combustion plants (over 50 MWth) are regulated according to the recently published BAT conclusions for large combustion plants (2021) and set at levels which represent the lowest emissions that are feasible under technically and economically viable conditions. These include mercury emissions. Therefore, the sector should already be compliant with the lowest achievable mercury emissions.

Our comments on responses to Question 3

The aim of EALs is to protect public health from emissions of chemical pollutants from a permitted activity, which may lead to elevated local and regional air concentrations compared to national ambient levels. While long-term use of EALs may achieve a reduction in UK-wide ambient air levels, this is not their primary objective.

The ability of existing or expected abatement techniques to reduce mercury emissions to the appropriate level should be modelled by applicants on an individual basis, given the different circumstances that may exist for each installation.

Q4. What would be the financial and operational implications for your company from adopting an even lower EAL for mercury, for example, with regards your production facilities, or the chemical make up of any of your products?

We received 2 responses to this question.

One respondent highlighted that any proposed changes to regulation need to be proportionate. Specifically, the respondent noted that in some cases, mercury may be present naturally in raw materials or fuels used in industrial processes, and therefore is unlikely that it can be removed entirely from a production process. High costs associated with disproportionate environmental regulation may lead international companies to relocate production outside of the UK, where it is cheaper to operate.

The second respondent was unable to provide information on financial implications.

Our comments on responses to Question 4

The Environment Agency, working with the UKHSA, has a responsibility to protect public health, and we are aware that international agreements are looking to lower mercury emission levels. We therefore will work with operators to identify solutions that address environmental, health and economic issues.

Q5. We recognise that some of our proposed changes to EALs may result in financial impacts on operators. If relevant, please provide an estimate of the financial costs (and supporting cost data) of the proposed EAL changes on your operations or your sectors operations.

We received 2 responses to this question. A third response, made to Question 6, was also related to this question.

One respondent, whilst fully recognising the responsibility of industry to protect public health and the environment, also highlighted that any proposed changes to regulation need to be proportionate. The respondent reiterated the issue of mercury being naturally present in some raw materials and fuels, hence difficult to remove entirely. Furthermore, the respondent noted that there is no abatement technology or BAT for dealing with some types of emissions, and that this needs to be recognised in any proposed changes to environmental regulation.

The second respondent was unable to provide information on financial implications.

Finally, a third respondent highlighted that for the acrylamide case mentioned in Question 2 (where an exceedance in emissions from an existing plant could be expected with the new EAL), abatement installation costs of £3 million per line and running costs of £600,000/year (the source of financial appraisal is unknown) per line were estimated. It was also noted that the abatement may be required for some of the lines regardless of the EAL review, due to the new UK BAT standards, although this was not yet clear.

Our comments on responses to Question 5

We appreciate any financial information that can be provided with regards the updated EALs, and we will use this to determine the need for a Business Impact Target assessment under the regulations. We reiterate that the new EALs will only apply to new plant permit applications and variations to existing applications. We are also aware that the stringent new UK BAT requirements may address the new EALs directly, although this will need to be tested on a case-by-case basis.

Q6. We are planning a third phase of EAL updates in the future. After this, we propose to withdraw any remaining existing EALs that were derived using our old, outdated method. To help us determine which substances to consider in the third phase of our EAL update work, please list any remaining substance EALs from the air emissions risk assessment guidance that are relevant to your permit applications.

We received 3 responses to this question (a fourth response, related to Question 5, has been addressed previously). A range of chemical substances were suggested for prioritising of EAL updating. This included the following.

Metals that have not had an updated EAL:

• antimony
• manganese
• vanadium
• cobalt
• lead
• tin

Substances emitted by a specific sector, which have not had a revised EAL:

• NOx (nitric oxide and nitrogen dioxide)
• sulphur dioxide
• hydrogen fluoride
• ammonia
• carbon monoxide

Highest priority EALs for a specific sector, relevant to current and future plant emissions:

• ammonia
• acetaldehyde
• antimony
• formaldehyde (annual mean)
• PCBs
• nitric oxide

Medium priority EALs:

• acetone
• butane
• diethyl ketone
• methyl ethyl ketone
• methyl propyl ketone, methanol, 1-propanol, 2-propanol, and toluene

Other listed substances where EALs have been used to set permit limits or requirements with regulators include:

• acrylic acid
• acrylonitrile
• methanol
• phenol

A respondent suggested that substances for which EALs may be required can be found in the relevant operators’ permit applications and environmental permits for the production sites in England.

A comment was also made that, as a minimum, EALs should be developed to cover all the substances included in the Environment Agency document ‘Monitoring stack emissions: techniques and standards for periodic monitoring’.

One respondent made clear that they did not support the withdrawal of EALs which are not included in the third phase review, stating the importance of EALs being available for a wide variety of species. The respondent supported retention of existing EALs in the absence of replacement values.

Finally, a respondent also noted the high importance of continuing progress on the derivation of EALs for a wider range of amines and amine degradation by-products to support decarbonisation of the power sector via carbon capture and storage.

Our comments on responses to Question 6

We are considering all of these suggested substances for the next phase of EAL development. Some of these substances already have an established regulatory limit value so we would not need to develop an EAL (for example, lead, nitrogen dioxide, carbon monoxide, sulphur dioxide). However, we will be unable to update EALs for all compounds, due to resource limitations, and we will need to prioritise accordingly. We will also continue to look to industry for the development of EALs for individual compounds (see the section on Question 7).

We have already prioritised EAL reviews based on substances reported by operators in our pollution inventory. We have now updated or reviewed EALs for the majority of commonly used substances which operators typically include when assessing the impact of their site operations. We will focus our work on updating any remaining key substances based on the information provided.

The withdrawal of some occupational exposure limits (OELs) by the Health and Safety Executive in the early 2000s, following the introduction of a new OEL framework (now known as Workplace Exposure Limits), means that the scientific data on which some of these levels were based has been removed and the values could no longer be considered reliable.

We are carrying out a separate strand of work, which is the development of EALs for an initial range of amines associated with the carbon capture and storage process that uses amines as capture solvents. We welcome operators’ suggestions on any additional amine and amine derivatives for which EALs should be made available, although we will expect operators to participate in EAL derivation (see the section on Question 7).

Q7. We want industry to take a more active role in future EAL development using the updated methodology we have developed. What tools do you require to develop EALs using our methodology?

We received 5 responses to this question. Generally, these voiced a preference for the regulator (Environment Agency) continuing to take the lead for EAL development. The regulator was seen as having the appropriate working knowledge and technical expertise, and the ability to provide a consistent approach to the assessment of emissions across industry. It was highlighted that the regulator should be provided with sufficient resource to support EAL development.

There was a call to clarify how consistency could be achieved if individual sites were developing their own EALs. In terms of tools, respondents requested clear guidance, for example in PDF rather than HTML format, with links to relevant data sources, and including flowcharts, appropriate uncertainty factors, and potentially Excel spreadsheet-based tools to support the activity and ensure consistency.  The methodologies presented in the 2012 and 2021 consultations on EALs were not considered to represent definitive guidance documents setting out the finalised accepted methodology.

To enable greater industry involvement in EAL development, one respondent felt that industry would require access to expertise in interpreting toxicological and epidemiological studies. The respondent also thought it would be useful to understand the processes that the Environment Agency will adopt to audit and review new EALs proposed by industrial process operators. There would also need to be increased transparency and availability of data from suppliers, to accurately consider developing EALs for new substances contained within materials.

One respondent recognised that there may be certain situations, such as for amine based post-combustion carbon capture, where a large variety of chemical compounds may require EALs within a short timescale. The onus may then be on industry to provide EALs, so that planning and permit applications could come forward in a timely fashion. These situations were viewed as the exception, not the rule.

One respondent, a trade organisation, supported any approach where its members are given a more active role in developing the regulatory regime with which they must comply. A regulatory regime which would be proportionate in its approach, maintain a robust mechanism to protect the environment and allow for the sector to develop and exploit new and emerging technologies that will ultimately allow it to reduce its impact on the environment was encouraged. Any tools and related methodologies that are used to develop EALs should reflect the assessments already undertaken by the trade organisation members.

Our comments on responses to Question 7

Given the constant and inevitable introduction of new chemical compounds to the environment, linked to the development of new technologies, it will be difficult for the Environment Agency alone to keep pace with EAL development for all substances. The need for operators to develop EALs individually is inevitable. The Environment Agency will work to make the process as uniform and accessible as possible for operators, to address the issues raised concerning consistency. The available guidance will be reviewed to facilitate its use. We highlight also that any EAL developed, whether by the Environment Agency or individual operators, and the related methodology, will need review and approval by the UKHSA prior to adoption.

Q8. Please tell us if you have any further comments on any of the information presented in our consultation and provide as much information as possible to support your answer.

We received 5 different responses to this question, which covered a number of different issues. We cover these in order.

Issues raised by respondent 1

The consideration of a further reduction of the limit of mercury was welcomed, as in many cases, health benefits can be expected from reductions in air pollutants below thresholds.  The respondent asked us to extend the consideration of lower limits to other air pollutants.

The respondent noted that, whilst the referenced document on the toxicity of ethylene oxide is dated 2020, the most recent included references for acrylamide, butadiene, cadmium, chromium III, hydrogen chloride, hydrogen cyanide, mercury, methyl chloride, methylene chloride, nickel, selenium are dated 2013 or earlier. The Environment Agency was urged to provide greater clarity regarding the processes undertaken to determine if there is more recent relevant research (and if there has, what research has been considered), or to clearly state that no such process has been undertaken.

Our comments on issues raised by respondent 1

The lower EALs proposed for mercury, and for other substances as presented in the consultation document, are based on available toxicological data. We would not recommend lower limits on air pollutants that would not be based on toxicological standards or information.

The EAL derivation work was undertaken based on a search of the most relevant authoritative opinions published up to the date of the EAL evaluation (mostly 2022 for phase 2). The date of publication of the referenced review in the consultation decision summary document is not necessarily the most recent document reviewed, but its information was nonetheless judged to be pivotal for the recommended EAL. The full appraisal document for any of the EALs presented, which sets out the literature reviewed, and the weighting given to the evidence in reaching any decision, is available on request.

Issues raised by respondent 2

The respondent suggested that the Environment Agency consider whether existing baseline data resources such as Defra’s UK AIR provide data at an adequate temporal resolution and detection limits to enable robust assessments to be carried out, without incurring excessive costs for complex baseline measurement surveys.

The Environment Agency was urged to set out any links between the use of EALs and information developed as part of the REACH process. For example, clarifying whether REACH dossiers potentially contain information that would be useful for applicants needing to define an EAL for a substance not listed by the Environment Agency.

An error was highlighted on the GOV.UK page listing EALs, related to the Toluene short term 1-hour EAL – it currently states 8000 µg/m³, this should be 800 µg/m³.

The query was raised whether the WHO 30-minute mean guideline for styrene based on avoiding adverse impacts due to odour should be included as an input to the process of identifying a short-term EAL for styrene.

The consistent use of µg/m³ was recommended, rather than mg/m³. Air risk assessment are all presented in µg/m³.

The status of 24-hour mean EALs was requested to be confirmed as either ‘long-term’ or ‘short-term’.

Our comments on issues raised by respondent 2

The UK Air data represents a combination of short-term (continuous) and longer-term (3-month) monitoring of ambient concentrations of individual atmospheric pollutants. The location of monitors is typically determined by individual local authorities, or by pollution hotspot requirements, rather than being linked to emissions from specific regulated facilities.  The EAL consultation does not alter our existing guidance on selecting ‘appropriate background’ concentrations when using our risk assessment tool. We do not routinely require ambient measurement survey to be conducted for permit applications.  Should we require such a survey, this would be based on site specific risks.

The EAL development is based on all available toxicological documentation on individual substances, including REACH dossiers. Hence REACH data should be considered, if available, together with any other relevant sources.

We recognise the error in the toluene value on the GOV.UK EAL list and will correct this. As stated in the consultation document (section 3.2), we will also correct the EALs for toluene to the WHO guideline values with a 1-week averaging time. The WHO guidelines will replace the current long-term (annual) EAL values because they are lower and over a shorter averaging period, therefore making them more precautionary. We will also provide a conversion factor to convert predictions to the 1-week averaging period. We are going to make these corrections on completion of the current consultation. Note that toluene has not yet gone through our new hazard characterization method for deriving updated EALs. This means that it remains a candidate for review in our upcoming third phase of EAL updates.

Styrene is one of the substances currently on our EAL list on GOV.UK, for which the EAL (800 µg/m³ as an annual mean) is based on the old OEL, and therefore will need updating. It is worth noting that EALs are designed to protect human health issues rather than address nuisance, and therefore the WHO styrene guideline for odour may not be directly relevant to EAL review. The Environment Agency addresses potential odour concerns through our odour permit condition, which states; “Emissions from the activities shall be free from odour at levels likely to cause pollution outside the site, as perceived by an authorised officer of the Agency, unless the operator has used appropriate measures, including, but not limited to, those specified in an approved odour management plan, to prevent, or where that is not practicable, to minimise the odour.” This condition allows the Environment Agency to regulate operators not to cause any type of odour pollution outside of their site boundary. We believe that this odour pollution condition is more powerful than an emission level and will result in permitted sites achieving the WHO guideline levels.

Use of mg/m³ rather than µg/m³ is related to previous documentation but will be considered for future publications.

We have addressed the issue of the 24-hour mean in our comments on responses to Question 2.

Issues raised by respondent 3

The respondent highlighted that the forthcoming Waste Gas Treatment for the Chemical Sector (WGC) UK BAT conclusions are likely to result in significant new abatement costs for permitted chemical sites in the UK. Sites may need to use EALs to demonstrate BAT linked to an ‘equivalent level of environmental protection’ or for demonstrations of best overall environmental outcomes (or BPEO – best practicable environmental option), especially where new abatement could have significant adverse cross media effects. The large volume inorganic chemicals installations, for which the BAT review will be commencing shortly, may have similar UK BAT compliance requirements.

The timing for implementation of the updated EALs will be linked to new permit variations or substantial variations but also to sector reviews. The respondent urged the Environment Agency not to implement the current or future phase of EAL changes until after publication of the ongoing UK BAT Waste Gas Treatment for the Chemical Sector and Large Volume Inorganic Chemicals BAT conclusions. this would avoid additional, or contradictory burdens, placed on industry. The respondent is seeking certainty that by meeting the new air emission limits associated with UK BAT, it will not need additional abatement (or monitoring) for channelled emissions classified as ‘minor’ under the new legislation.

The respondent suggests that where EALs involve substances that are released naturally (naming as an example chloromethane) or by non-industrial sectors or factors (for example, domestic, or urban), a proportionate approach should be taken when considering industrial contribution or risk compared to other sources. This would avoid potentially expensive abatement and its associated negative indirect cross media impacts (for example, CO2 emissions, water use, waste production etc) for the overall benefit of UK industry and the environment.

The respondent queried the difference between OELs and EALs, and differences in derivation, querying which limit would take priority for the protection of human health, and raising the issue that operators should not be required to go above and beyond other human health protective legislation requirements.

The respondent highlighted the European Commission’s proposal for a revision of the Ambient Air Quality Directives (on 26 October 2022). A briefing called for the target values for some substances (including cadmium) to be made limit values.  In such a situation, there could be a difference between the limit value and the Environment Agency’s new proposed short term EAL for cadmium.  Also, the 2021 EU Committee for Risk Assessment (RAC) European Chemicals Agency opinion does not derive a STEL (short term exposure limit value) linked with occupational exposure. This comment is made to highlight the difference and is raised in case it results in an uneven playing field between UK and EU operations.

The respondent pointed out that the summary table in the consultation (Table 1) states that both the short term and long term EAL are being withdrawn for methyl chloride and dichloromethane. However, the Appendix to the consultation states that there will be a long term EAL for these substances. This needs clarification.

Our comments on issues raised by respondent 3

With regards the links between BAT conclusion requirements and EALs, we refer to our responses to Questions 2 and Question 5.

The EAL derivation process is a risk assessment exercise, which must consider the health impacts of individual chemicals released by industry.  We recognise that some sources of unregulated emissions can be significant, and we are aware that these are being addressed through alternative means by the relevant government departments.

OELs or workplace exposure limits are intended to protect the health and safety of workers and other visitors in the workplace. EALs are intended to protect the health of the public, who are beyond the boundary of the works or premises, from emissions to the environment.  Hence derivation limits and values may be different.

As the UK has now left the European Union, we are required to determine the BAT for specific industry sectors as defined in relevant domestic legislation.  The UK BAT process is an evidence-led consensus process to identify the best techniques that are available to UK industry.  BAT conclusions will be published as Statutory Instruments and will be the basis for permit conditions for the relevant sector.  UK BAT conclusions will be determined by technical working groups formed of members of national regulators as well as industry, non-government organisations, academia and equipment manufacturers. Under the EU exit arrangements, from the 1 January 2022 UK BAT conclusions will have precedent over any equivalent document produced by the EU.

With regards methyl chloride and dichloromethane, we confirm that Table 1 in the consultation is consistent with the Appendix information. Both the table and the Appendix state that:

• for methyl chloride, the short-term EAL is being withdrawn, and a long-term EAL of 0.018 mg/m³ 24-hr mean is proposed
• for dichloromethane, the current short-term and long-term EALs are being withdrawn, and a short-term EAL of 2.1 mg/m³ 24-hr mean is proposed, as well as a long-term EAL of 0.77 mg/m³ annual mean

Issued raise by respondent 4

The respondent again raised the issue of inconsistency between short-term or long-term for 24-hour mean, identified for a number of new substances EALs. There are different guidelines for how to treat short-term and long-term EALs in the GOV.UK guidance on air emissions risk assessment for your environmental permit, hence the importance of clarifying whether a particular EAL is a short-term one or long-term.

Our comments on issues raised by respondent 4

Please see our comments on responses to Question 2 with regards the issue of the 24-hour mean. We will review our guidance to address the 24-hr mean long term and short-term issue.

Issues raised by respondent 5

The respondent raised concerns about confusing between long-term and short-term EAL values and annual means. In particular, the respondent flagged the following.

They raised concerns over the terminology and presentation of the EALs for ‘threshold’ and ‘non-threshold’ effects in the consultation, to be clarified in published guidance.

They flagged the need to clarify the differentiation between short-term and long-term environmental standards. Specifically, for chromium III, copper, hydrogen cyanide, methyl chloride and selenium, current short-term and long-term EALs are withdrawn and replaced with a 24-hour EALs listed as long-term EALs. The respondent suggested these should be short-term EALs, based on the averaging period, for consistency with the Environment Agency air emissions risk assessment guidance.

For mercury, they said the previous 1-hour short-term EAL has been made more stringent, and the previous annual mean has been replaced by a 24-hour EAL listed as a long-term EAL. The presentation creates confusion in (i) assessing the increase in stringency (a factor of 74 times comparing with the previous short-term EAL) and (ii) clarity on the averaging period for dispersion modelling and the screening criteria.

They flagged the need for clarity around the EAL values (annual, short term, long term) to be used in the air quality modelling.

They raised concerns about the derivation of the short-term EAL for 1-3 butadiene. This is because the current long-term (annual mean) UK air quality strategy objective for the chemical is 2.25 mg/m³. A new short-term EAL, also of 2.25 mg/m³ (and therefore much more stringent than the long-term objective) is proposed, however, this is based on a long-term chronic exposure study of 9 to 24 months. It is therefore unclear why a 24-hour EAL is being proposed.

Our comments on issues raised by respondent 5

With regards 24-hr averaging times versus annual and short-term exposure, and threshold and non-threshold effects, please see our response in Question 2. We will clarify these differences in our guidance to ensure that stakeholders have clear information for their risk assessments.

Several short- and long-duration studies have reported potential reproductive and developmental effects in laboratory animals from butadiene inhalation. There are some caveats to these studies with respect to species differences in metabolism, and the derived health-based guidance values may overestimate the human risk. However, potential reproductive and development effects cannot be excluded. As the UK Air Quality Strategy objective is an annual value and given the sensitive effect of concern, a short-term EAL of equal numerical value but applied over a shorter exposure duration, 24 hours, is recommended.

4. Next steps

Once this document is published, we will update the relevant EAL values on GOV.UK and start to use the new EALs in our regulatory activities.  Side-by-side with this, we will review and clarify the related guidance to address issues raised by the consultation responses.  For all new permit applications and for all substantially changed permits, the new values will apply from the day of publication. For all existing permits, the new values will be implemented when permits are subject to sector review, on a case-by-case basis depending on the circumstances.

The Growth Duty applied from 2017 through the Deregulation Act 2015, requires the Environment Agency and other national regulators to have regard to the desirability of promoting economic growth, alongside our other statutory duties. We have included questions in the consultation to help us obtain the necessary information to meet this requirement in relation to the proposed new EALs.

We are also working with colleagues in UKHSA to finalise proposals on an additional update of existing EALs, which will feature within a third consultation.

Email us at [email protected] if you wish to be notified of the launch of the next consultation.

Appendix A: consultation questions

In the consultation we asked the following.

Q1. Which of the listed substances for which we are proposing updated EALs do you routinely use to assess the impact of your proposed emissions in support of permit applications?

Q2. Do you expect the proposed changes to these EALs to affect your operations, and if so, how?

Q3. Is a long-term EAL for mercury lower than the current proposal practical for your industry and your business?  What level of reduction could be achieved by implementation of best available techniques for emissions abatement? 

Q4. What would be the financial and operational implications for your company from adopting an even lower EAL for mercury, eg with regards your production facilities, or the chemical make up of any of your products?

Q5. We recognise that some of our proposed changes to EALs may result in financial impacts on operators. If relevant, please provide an estimate of the financial costs (and supporting cost data) of the proposed EAL changes on your operations or your sectors operations

Q6. We are planning a third phase of EAL updates in the future. After this, we propose to withdraw any remaining existing EALs that were derived using our old, outdated method. To help us determine which substances to consider in the third phase of our EAL update work, please list any remaining substance EALs from the air emissions risk assessment guidance that are relevant to your permit applications.

Q7. We want industry to take a more active role in future EAL development using the updated methodology we have developed. What tools do you require to develop EALs using our methodology?

Q8. Please tell us if you have any further comments on any of the information presented in our consultation and provide as much information as possible to support your answer.

Appendix B: consultation respondents

The following bodies or organisations responded to our consultation:

• British Glass
• Chemical Industries Association
• Institute of Air Quality Management
• Mineral Products Association
• Uniper Energy
• UNISON
• United Kingdom Without Incineration Network (UKWIN)

We also had one anonymous contribution – we have included the comments from this.