Open consultation

Consultation document

Published 19 August 2026

About this consultation

The consultation is open to the public, but is primarily aimed at industrial users of GBL and 1,4-BD, including end users of products containing these substances, and importers. The proposals will apply throughout the UK.

Duration: From 19 August 2026 to 11 November 2026.

Enquiries to:

Drugs and Alcohol Unit
Home Office

Email: GBLconsultation@homeoffice.gov.uk

How to respond: Please submit your response by completing the online form.

Additional ways to respond: A series of stakeholder meetings is also taking place. For further information please use the ‘Enquiries’ contact details above.

Response paper: A response to this consultation exercise is due to be published by 8 February 2027 at: https://www.gov.uk/government/consultations/control-of-gamma-butyrolactone-and-14-butanediol.

Executive Summary

This consultation seeks views on a proposal to tighten controls on the substances Gamma-Butyrolactone (GBL) and 1,4-Butanediol (1,4-BD). GBL and 1,4-BD are controlled drugs that are closely related to Gamma-hydroxybutyric Acid (‘GHB’). Together, these drugs are referred to as ‘GHB and related substances’ (‘GHBRS’). GHBRS can cause profound unconsciousness and have been used in crimes such as drug-facilitated sexual assault (DFSA), murders, and robberies. GBL and 1,4-BD, however, are subject to a conditional exemption from licensing controls because they have many uses in industry.

The proposal is to abolish the current broad exemption from drugs licensing for industrial users of these substances, and replace it with an exemption for mixtures containing them. This will mean that those who handle high purity GBL and 1,4-BD will need a licence, but many legitimate products that contain them will be exempt from licensing controls, as long as they are not intended for ingestion. In line with the Government’s ambition to tackle violence against women and girls, the intention of this proposal is to inhibit the ability of criminals to access GBL and 1,4-BD and therefore restrict the means by which drug facilitated sexual assault may be perpetrated.

The consultation is open to the public but targeted towards industrial users of these two substances.

Introduction

1) Gamma-Butyrolactone (GBL) and 1,4-Butanediol (1,4-BD), also referred to as ‘BDO’) are controlled as Class B drugs under the Misuse of Drugs Act 1971 (the 1971 Act). They are closely related to gamma-hydroxybutyric acid (GHB), which is also a Class B drug. However, GBL and 1,4-BD have legitimate uses in industry. They are subject to a qualified exemption, under both the Misuse of Drugs Regulations 2001 (which applies in Great Britain) and the Misuse of Drugs Regulations (Northern Ireland) 2002 (“the 2001 and 2002 Regulations”) from the need to possess a controlled drugs licence to import, export, supply, possess, or produce them if they are not intended for human ingestion (other than as a flavouring in food). Evidence from criminal cases shows that the current exemptions are exploited to enable illicit supply.

2) This consultation seeks views on how to effectively tighten controls on GBL and 1,4-BD, while avoiding a disproportionate negative impact on legitimate industrial use. The Government’s proposal would require those dealing with high-purity GBL and 1,4-BD to obtain a licence to import, export, supply, possess, or produce them, while seeking to ensure that legitimate products made with them remain exempt from licensing.

3) Following several criminal convictions for rape, murder, and robbery in which the offenders had used GHB or a related substance to incapacitate their victims, the Advisory Council on the Misuse of Drugs (ACMD), an independent scientific advisory body, reviewed the harms of these substances and reported on 20 November 2020^{[footnote 1]}.

4) The ACMD recommended that the three drugs GHB, GBL and 1,4-BD be moved from Class C to Class B under the 1971 Act. This measure was accepted by the then government and brought into effect on 13 April 2022. The move to Class B increased the maximum penalty for unlawful possession from two years’ imprisonment, or a fine, or both, to five years’ imprisonment, or a fine, or both.

5) The ACMD also recommended that GBL and 1,4-BD should be placed in Schedule 1 to the 2001 and 2002 Regulations and the qualified exemption abolished. The result of this would have been that industrial users required a licence to import, export, possess, produce or supply GBL and 1,4-BD.

6) The recommendation was intended to tackle the sale of these drugs as purported industrial products (e.g. “cleaning products”) while intended for the illicit market. The then government accepted this recommendation. However, concerns were raised about the extent of the impact on industry.

7) This consultation proposes a revision to the current qualified exemption from licensing for GBL and 1,4-BD. The proposal would require users of high-purity GBL and 1,4-BD to obtain a controlled drugs licence. The consultation is open to the public but is primarily aimed at industrial users of GBL and 1,4-BD in the UK. As well as manufacturers, this includes end users of products containing GBL and 1,4-BD, importers to the UK, and those providing transport and storage services for these substances.

Scope of the measures

8) The 1971 Act applies UK-wide. However, in Northern Ireland the Assembly has separate legislative competence for regulations made under 1971 Act. This consultation is issued jointly by the Home Office and the Northern Ireland Department of Health, and the proposals are expected to have effect UK-wide.

How to respond

9) Responses will be accepted via the online survey over a course of 12 weeks from 19 August to 11 November 2025.

A link to this consultation document is being shared with the following industry bodies, and they are invited to share it with their members:

• The British Coatings Federation
• The Alliance of Chemical Associations
• The Chemical Business Association
• The Chemical Industries Association

This list is not meant to be exhaustive or exclusive, and responses are welcome from anyone with an interest in or views on the subject covered by this consultation.

Options Assessment

10) An options assessment is available, which seeks to make an economic assessment of the costs and the benefits that may arise from two proposed changes to the regulation of GBL and 1,4-BD. The assessment compares an exemption for mixtures of 70% purity or less (called Option 1) with an alternative, wider exemption for mixtures of 99% purity or less (called Option 2). The consultation responses will be used to determine whether to proceed and, if so, the concentration threshold of implemented in the legislation, which could be an alternative threshold to the two options assessed. The key costs to business derive from the requirement for businesses to obtain controlled drug licences, including:

• The cost of fees for domestic controlled drugs licence; and the cost of import and export licences.

• The cost of obtaining Disclosure and Barring Service (DBS) checks for staff.

• The cost of administration and compliance connected to licensing.

• The cost of businesses familiarising themselves with the above requirements.

11) As set out in the Options Assessment, industrial users of GBL and 1,4-BD in the UK, particularly those using high purity GBL and 1,4-BD, will be affected by the proposals for a revised exemption. This includes manufacturers, importers, end users of products containing GBL and 1,4-BD, and those providing transport and storage services for these substances.

12) For businesses requiring a licence, associated fees are expected to cost £4,700 per business in year 1, and total £8,900 across 10-years. The annual monetised cost across all businesses estimated to be in scope of Option 1 is estimated to range between £75,900 and £732,100, with a central estimate of £142,200. This is the “present value” of the costs. For Option 2, annual costs to business are estimated to range between £64,500 and £341,600, with a central estimate of £99,500. The options assessment recognises that there will be further costs of compliance for businesses that require a licence that have not been monetised.

13) Please see the attached options assessment for further detail on the analysis and estimated costs. Comments on the options assessment are welcome.

Legal Disclaimer

14) Nothing in this document or the accompanying Options Assessment constitutes legal advice. Those who wish to handle controlled drugs for lawful purposes may wish to seek their own legal advice.

The proposed exemption for mixtures

15) The Government proposes that high purity GBL and 1,4-BD should be placed in Schedule 1 to the 2001 and 2002 Regulations and require a licence, while mixtures containing up to 70% GBL or 1,4-BD are subject to a qualified exemption under Option 1, and an alternative 99% under Option 2. While these are the proposed options, feedback received during the consultation will help determine the final decision. The proposed exemption seeks to ensure that many legitimate products (such as inks and coatings) made with GBL and 1,4-BD remain exempt from licensing controls. The proposed exemption for mixtures is described in more detail below.

Effect of a qualified exemption

16) Products to which the proposed exemption applies would have a similar status to GBL and 1,4-BD under the present exemption (see box below) from licensing requirements under regulation 4B of the 2001 and 2002 Regulations. They would remain controlled drugs but would be exempt from licensing requirements if they meet the criteria for exemption.

17) As under the present 4B exemption, the exemption would not apply if the product were for human ingestion, other than as a flavouring in food. This means that (for example) if a person possesses a product to which the exemption would otherwise apply, but with the intention of supplying it for ingestion, then the exemption would not apply, and the person would be liable to prosecution.

18) The exception “other than a flavouring in food” is an exception from the general rule that the substance must not be for ingestion. The remaining conditions of the exemption would have to apply. Our understanding is that food flavourings contain percentages of GBL that are far below those in the proposed exemption. In finished food products, the percentage of GBL will be much lower still.

19) It is important to note that a manufacturer who makes a product that is exempt will nevertheless require a controlled drug licence if they use non-exempt GBL or 1,4-BD in manufacturing the product.

Definition of GBL and 1,4-BD under the 1971 Act

20) In addition to the control of ‘GBL’ and ‘1,4-BD’ in the 1971 Act, their stereoisomeric forms, salts, and any preparation or product containing them are also controlled. Therefore, the current regulation 4B exemption extends to them, and our proposed exemption will do so too (as long as the other conditions are met). The definition does not include esters and ethers of either GBL or 1,4-BD. Our proposals will not change this position. It should be noted that the current exemption, set out below, clarifies that esters and ethers of 1,4-BD are exempt despite this being strictly unnecessary. Our view is that this clarification does not need to be reflected in the revised exemption.

The current exemption under Regulation 4B of the 2001 Regulations

The 2002 Regulations make equivalent provision.

Exceptions for gamma–butyrolactone and 1,4-butanediol

(1) Gamma–butyrolactone and 1,4-butanediol are excepted from sections 3(1) (import and export), 4(1) (production and supply) and 5(1) (possession) of the Act save where a person imports, exports, produces, supplies or offers to supply either substance, or has either substance in his possession, knowing or believing that it will be used for the purpose of human ingestion whether by himself or another person other than as a flavouring in food.

(2) In this regulation references to gamma–butyrolactone include:

(a) any salt of gamma–butyrolactone; and

(b) any preparation or other product containing gamma–butyrolactone or a substance specified in sub-paragraph (a) of this paragraph.

(3) In this regulation references to 1,4-butanediol include:

(a) any substance which is an ester or ether or both an ester and ether of 1,4-butanediol;

(b) any salt of 1,4–butanediol or of a substance specified in sub-paragraph (a) of this paragraph; and

(c) any preparation or other product containing 1,4–butanediol or a substance specified in sub-paragraph (a) or (b) of this paragraph.

The rationale for an exemption: Schedule 1 licensing requirements

21) If the current exemption were abolished and not replaced, the legislation would capture GBL and 1,4-BD (and products containing them) when they are part of a mixture. Some end products (for example, inks containing GBL) would therefore be captured by the licensing requirement. It should be noted that mixtures or products that have undergone a chemical reaction, such that there is no longer any GBL or 1,4-BD present, would not be captured by the controls of the MDA 1971 either currently or under our proposals (unless they had other controlled drug content).

22) Those possessing Schedule 1 drugs ordinarily require a controlled drugs licence (issued by the Home Office) to import, export, possess, produce or supply them. The initial cost of a licence in England, Scotland and Wales can be up to £4,700, with an annual fee of £326 or (if a site visit is required) £1,371 thereafter. Each person named on the licence must have a valid Disclosure and Barring Service (DBS) check. There are also requirements in respect of, for example, safe custody and record-keeping. The process for obtaining a licence is set out at the following link: https://www.gov.uk/government/publications/domestic-licensing-application-guidance/domestic-licensing-application-guidance-accessible-version

23) It is not practical for end users to acquire controlled drugs licences. Therefore, we propose to limit the licensing requirement to those dealing with high-purity GBL and 1,4-BD. Note that the proposed exemption would (if the criteria are met), apply throughout supply chains and not be limited to finished products.

The proposed exemption for mixtures: details and definitions

24) We propose an exemption for products in which (under Option 1) the concentration of GBL or 1,4-BD in the ‘mixture’ is 70% by weight/ weight (‘w/w’)^{[footnote 2]} or lower. This is based on the rule in the United States for mixtures containing GBL^{[footnote 3]}.

25) We propose that the exemption will only apply to the extent that GBL or 1,4-BD is mixed with an organic solvent (or solvents) and not merely with water, alcohol, or GBL (in the case of a mixture containing 1,4-BD) or 1,4-BD (in the case of a mixture containing GBL). The intention of these limitations is to ensure that those supplying products that are intended for the illicit market cannot merely dilute their products and continue as before. It should be noted that:

a. The intention is not to entirely prohibit the presence of water or alcohol in the mixture. Therefore, the effect would be that, when those substances are present, the mixture can still benefit from the exemption, but water and alcohol would not count towards the 30% organic solvents.

b. GBL and 1,4-BD cannot be mixed together to meet the exemption criteria.

26) The proposed definition of ‘mixture’ is “a mixture or solution composed of two or more substances”^{[footnote 4]}.

27) The proposed definition of ‘substance’ is “a chemical element and its compounds in the natural state or obtained by any manufacturing process, including any additive necessary to preserve its stability and any impurity deriving from the process used, but excluding any solvent which may be separated without affecting the stability of the substance or changing its composition).”

28) The proposed definition of ‘organic solvent’ is a carbon-based substance capable of dissolving or dispersing one or more other substances.

Industry suggestions for further exemptions and other issues

Vestiges following manufacturing

29) Some stakeholders have told us that products (such as food packaging) can contain vestiges of 1,4-BD left over from the manufacturing process. Such vestigial amounts, on consumer products, are likely to be an ‘Exempt Product’ under the 2001 and 2002 Regulations and therefore exempt from drug controls^{[footnote 5]}. However, the definition of an ‘Exempt Product’ was not designed for bulk industrial products and has an absolute maximum of 1mg of the controlled drug and there may be circumstances where the ‘Exempt Product’ definition is exceeded. Therefore, it has been suggested that we should introduce an exemption specifically to address this problem.

30) However, it has alternatively been suggested that no significant amount of 1,4-BD remains on products in these circumstances, because it quickly evaporates, so that there is no risk of such products being captured by drugs controls. Therefore, we do not intend to introduce a specific exemption for ‘vestiges’, but we would welcome views on the issue from respondents with expertise on this topic.

Mechanisms

31) Products exist that use the physical properties of GBL – its boiling point and volumetric thermal expansion - as a part of a mechanism. Therefore, stakeholders have proposed an exemption that excludes products that use GBL or 1,4-BD as an integral part of a mechanism from licensing requirements.

32) However, we think that use within mechanisms is a highly uncommon application of these substances. Therefore, we do not intend to introduce a specific exemption for ‘mechanisms’, but we would welcome views on the issue from respondents with expertise on this topic.

Duties arising from Schedule 1 Status, and their application to transportation, storage and waste disposal

33) The requirements for non-exempt Schedule 1 GBL and 1,4-BD will be the same as for other Schedule 1 controlled drugs, in principle. Those holding Schedule 1 drugs under licence will be subject to the 2001 and 2002 Regulations, including requirements on record-keeping (the duty to keep a register and record quantities received, supplied and destroyed). They will also be subject to the conditions on their licence, including safe custody requirements; that thefts and losses should be reported to the Home Office’s Drugs and Firearms Licensing Unit; and that destruction should be witnessed by an authorised person named on the licence. This section does not seek to enumerate all licensing requirements, but addresses aspects of how GBL and 1,4-BD are transported and stored in bulk that licence holders and carriers will need to be aware of.

Transportation and storage

34) The 2001 and 2002 Regulations contains provision to enable carriers to possess controlled drugs and supply them to anyone who may lawfully possess them, without requiring a licence^{[footnote 6]}. The exemption applies to “..a person engaged in the business of a carrier when acting in the course of that business..”. Therefore, the exemption only applies when they are acting in the course of that business and does not enable them to carry out other activities without a licence. The proposals may therefore have implications for non-exempt GBL and 1,4-BD in transit and in storage.

35) The Home Office’s position on controlled drugs in transit, and the appropriate security measures, is set out in the “Guidance for the safe custody of controlled drugs and drugs precursors in transit”, which is available at the following link: Guidance for the safe custody of controlled drugs and drug precursors in transit (accessible version) - GOV.UK (www.gov.uk). As set out in this guidance, controlled drugs remain the responsibility of the supplier until the recipient acknowledges receipt, and they should ensure appropriate security measures. Locations where controlled drugs are stored overnight or for periods longer than 24 hours and/or subject to treatment require licences granted by the Home Office.

36) Under our proposals, high purity GBL and 1,4-BD will be subject to licensing requirements. This will include locations where they are stored overnight, including ports beyond customs control (where imports may be stored while transport is arranged), and warming or heating stations for 1,4-BD. Standard conditions will apply at these locations as they do to other licensed premises.

Waste disposal and destruction

37) The 2001 and 2002 Regulations place a requirement that those who possess, produce and supply controlled drugs, and are required to keep records in respect of them, should only destroy them in the presence of (and in accordance with the instructions of) an authorised person. This can be someone authorised under the legislation, but for a business operating under a licence it will ordinarily be a person named on the licence as an authorised witness. Carriers acting in the course of their business as carriers are exempt from the requirement to keep records, and therefore from the duty to record destruction.

38) GBL and 1,4-BD are sometimes transported by road in tankers or supplied in tanks called “intermediate bulk containers” (IBCs). Businesses that do not qualify for the exemption for carriers and who (for example) clean or recondition tankers or IBCs that contain non-exempt GBL or 1,4 may therefore need a licence under our proposals.

About this consultation

Contact details

Please respond to the consultation using the online form by 11 November 2026. For any queries about the consultation,

the Drug Legislation Team
Email: GBLconsultation@homeoffice.gov.uk

Complaints or comments

If you have any complaints or comments about the consultation process you should contact the Home Office at the above address.

Publication of response

A paper summarising the responses to this consultation will be published as soon as possible after the consultation closes, expected to be within three months. The consultation will be published on gov.uk.

Confidentiality

The government’s published response will not include the personal information of respondents. However, information provided in response to this consultation, including personal information, may be published or disclosed in accordance with the access to information regimes (these are primarily the Freedom of Information Act 2000 (FOIA), the Data Protection Act 2018 (DPA), the General Data Protection Regulation (GDPR) and the Environmental Information Regulations 2004).

If you want the information that you provide to be treated as confidential, please be aware that, under the FOIA, there is a statutory Code of Practice with which public authorities must comply and which deals, amongst other things, with obligations of confidence. In view of this it would be helpful if you could explain to us why you regard the information you have provided as confidential. If we receive a request for disclosure of the information we will take full account of your explanation, but we cannot give an assurance that confidentiality can be maintained in all circumstances. An automatic confidentiality disclaimer generated by your IT system will not, of itself, be regarded as binding on the Home Office.

The Home Office will process your personal data in accordance with the DPA and in the majority of circumstances, this will mean that your personal data will not be disclosed to third parties.

Options Assessment

The Options Assessment is available here

Consultation principles

The principles that government departments and other public bodies should adopt for engaging stakeholders when developing policy and legislation are set out in the consultation principles.

https://www.gov.uk/government/publications/consultation-principles-guidance

Any enquiries regarding this publication should be sent to us at GBLconsultation@homeoffice.gov.uk

1. The ACMD’s report “Assessment of the harms of gamma-hydroxybutyric acid, gamma-butyrolactone, and closely related compounds” is available at the following link: Assessment of the harms of gamma-hydroxybutyric acid, gamma-butyrolactone, and closely related compounds - GOV.UK (www.gov.uk) ↩

2. W/w is the weight of a solute divided by the total weight of the solution, expressed as a percentage. ↩

3. Federal Register: Exempt Chemical Mixtures Containing Gamma-Butyrolactone ↩

4. The proposed definitions of “mixture” and “substance” (and the potential definition of “article”, see below) are adapted from the GB Classification and Packaging Regulations. Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006 (Text with EEA relevance) (legislation.gov.uk) ↩

5. An “exempt product” is defined in Regulation 2 of the 2001 Regulations. The 2002 Regulations make equivalent provision. To be an exempt product, all three limbs of the definition must be met: “An “exempt product” means a preparation or other product consisting of one or more component parts, any of which contains a controlled drug, where:
   
   • the preparation or other product is not designed for administration of the controlled drug to a human being or animal;
   • the controlled drug in any component part is packaged in such a form, or in combination with other active or inert substances in such a manner, that it cannot be recovered by readily applicable means or in a yield which constitutes a risk to health; and
   • no one component part of the product or preparation contains more than one milligram of the controlled drug or one microgram in the case of lysergide or any other N-alkyl derivative of lysergamide.” ↩

6. The 2001 Regulations Reg 6. ↩