COSHH ACOP L5: What It Is and Why It Matters

What Is the COSHH ACOP? (Short Answer)

The COSHH ACOP is L5 — Control of substances hazardous to health: Approved Code of Practice and guidance, sixth edition, published by HSE in 2013 and in effect since 2 December 2013. It sets out the preferred methods for complying with the COSHH Regulations 2002.

It is not law. But it is not ordinary advice either. If you are prosecuted and it is shown you did not follow the relevant provisions of the Code, the court will find you at fault unless you can demonstrate you complied some other way. That reversal — you having to prove compliance rather than the prosecution having to disprove it — is the whole point of an ACOP, and it is why "we didn't follow the ACOP, but it's only guidance" is a weak position to be in.

The Code is a free download from HSE.

Where the Special Legal Status Comes From

L5 describes its own status in a standard notice at the front of the book:

"This Code has been approved by the Health and Safety Executive, with the consent of the Secretary of State. It gives practical advice on how to comply with the law. If you follow the advice you will be doing enough to comply with the law in respect of those specific matters on which the Code gives advice. You may use alternative methods to those set out in the Code in order to comply with the law.

However, the Code has a special legal status. If you are prosecuted for breach of health and safety law, and it is proved that you did not follow the relevant provisions of the Code, you will need to show that you have complied with the law in some other way or a Court will find you at fault."

That status is not self-declared — it comes from section 17 of the Health and Safety at Work etc. Act 1974. Section 17(1) starts by making clear an ACOP breach is not itself an offence:

"A failure on the part of any person to observe any provision of an approved code of practice shall not of itself render him liable to any civil or criminal proceedings…"

Then section 17(2) does the real work:

"Any provision of the code of practice which appears to the court to be relevant to the requirement or prohibition alleged to have been contravened shall be admissible in evidence in the proceedings; and if it is proved that there was at any material time a failure to observe any provision of the code which appears to the court to be relevant to any matter which it is necessary for the prosecution to prove in order to establish a contravention of that requirement or prohibition, that matter shall be taken as proved unless the court is satisfied that the requirement or prohibition was in respect of that matter complied with otherwise than by way of observance of that provision of the code."

Stripped of the statutory grammar: if the prosecution shows you departed from a relevant ACOP provision, the thing they were trying to prove is taken as proved — unless you satisfy the court you met the duty another way. The ACOP does not create the offence. It shifts who has to do the explaining.

L5 Is Really Two Documents

This is the part almost every summary of L5 gets wrong, and it matters if you are trying to work out how much weight a particular paragraph carries.

L5 contains ACOP material and ordinary guidance material, bound together, with different legal weight. The book says so directly:

"In this publication, the ACOP text is set out in bold and the accompanying guidance in normal type, the text of the Regulations is in italics. Coloured borders also indicate each section clearly."

And the guidance carries a completely different notice from the one quoted above:

"This guidance is issued by the Health and Safety Executive. Following the guidance is not compulsory, unless specifically stated, and you are free to take other action. But if you do follow the guidance you will normally be doing enough to comply with the law."

So within a single book:

Bold text = ACOP. Special legal status. Depart from it and you carry the burden of showing you complied otherwise.
Normal type = guidance. Genuinely optional. Helpful, persuasive, but no reversed burden.
Italic text = the Regulations themselves. Actual law.

If someone tells you "L5 says you must do X", the useful follow-up question is which typeface it said it in. The two are interleaved regulation by regulation, so status is a property of the paragraph in front of you, never of the chapter or the page it sits on.

Which Edition Is Current

The sixth edition is the current one. Its Notice of Approval records the mechanics:

"By virtue of section 16(4) of the Health and Safety at Work etc Act 1974, and with the consent of the Secretary of State for Work and Pensions, the Health and Safety Executive has on 30 October 2013 approved the revised Code of Practice entitled Control of substances hazardous to health (Sixth edition, 2013, L5)."

The same notice withdrew the fifth edition, which "came into effect on 6 April 2005 and which shall cease to have effect on 2 December 2013", and confirms: "The Code of Practice comes into effect on 2 December 2013."

The sixth edition updated the material supporting regulations 7, 9, 10 and 11 to reflect the introduction of the REACH and CLP regulations. If you are working from a printed copy, check the spine — a fifth-edition L5 has been withdrawn for over a decade, and its ACOP provisions no longer carry section 17 status.

Where the ACOP Actually Bites

The ACOP is not an abstraction. It is often the source of duties people assume sit in the regulations.

The clearest example is respiratory protection. The COSHH regulations never use the phrase "fit test". HSE's fit-testing guidance explains where the duty really comes from:

"the Approved Codes of Practice (ACOPs) supporting the Control of Substances Hazardous to Health Regulations (COSHH), the Control of Lead at Work Regulations, the Control of Asbestos Regulations, the Confined Spaces Regulations and the Ionising Radiations Regulations stipulate that tight-fitting RPE should be fit tested as part of the selection process."

So the fit-testing obligation you will be judged against lives in the ACOP, not the regulation — which, given section 17, makes it close to mandatory in practice. We cover the detail in our guide to RPE and fit testing under COSHH.

The same pattern shows up around what counts as adequate control under Regulation 7, when health surveillance is appropriate, and how monitoring records should be kept. The regulation states the duty in general terms; the ACOP says what discharging it looks like.

What to Do With This

You do not need to read 100 pages of L5 to run a compliant COSHH programme. But it is worth:

Downloading the current PDF and keeping it where your assessments live, so you can check a provision when a question comes up rather than relying on a third-party summary.
Checking typeface before treating something as binding — bold is ACOP, normal is guidance.
Reading the sections that match your actual controls. If you rely on extraction, read the regulation 9 material. If you use RPE, read the regulation 7 material.
Recording your reasoning when you depart from it. Alternative methods are explicitly allowed — "You may use alternative methods to those set out in the Code in order to comply with the law." What section 17 requires is that you can show it. A note in the assessment explaining why your approach meets the duty is what turns a departure into a defensible decision.

That last point is the practical heart of it. The ACOP does not forbid doing things differently. It just means the burden of justifying the difference sits with you — and burdens are much easier to discharge when the reasoning was written down at the time rather than reconstructed afterwards.

Quick ACOP Checklist

Current L5 (sixth edition, 2013) downloaded and accessible
Any printed copy checked — fifth edition and earlier are withdrawn
Team understands bold = ACOP, normal type = guidance
Sections matching your actual control measures have been read
Departures from ACOP provisions are documented with the reasoning
COSHH assessments reference the standards you are working to
Your compliance checklist reflects ACOP expectations, not just the bare regulations

Recording the Reasoning

The ACOP's alternative-methods allowance is only as good as your ability to evidence it years later, when the person who made the decision has moved on. That evidence belongs with the assessment it relates to, not in a separate folder nobody opens.

COSHHmate is being built to keep the reasoning attached to the assessment — what control you chose, why, and what you were working to — so a departure from the recommended method reads as a documented decision rather than an oversight. Pricing will be a flat monthly fee with no per-user charges. To keep your COSHH decisions defensible, join the waitlist.

Sources

This is general guidance based on the Health and Safety at Work etc. Act 1974, the COSHH Regulations 2002 and the published L5 Approved Code of Practice. How a court would treat a particular departure from the Code depends on the facts — take advice from a qualified health and safety professional or solicitor for your specific situation. Not legal advice.