SDS Section 6: Accidental release measures

The section you read while it is still spreading

Section 4 is read by whoever is holding the casualty. Section 5 is read by the fire officer at the gate. Section 6 is read twice — first by whoever was nearest the drum when it went over, then by the person who arrives some minutes later, properly equipped. REACH Annex II splits subsection 6.1 along exactly that line. Most sheets do not.

Before either reader gets an answer, the opening instruction sets a condition on everything below it: the response shall distinguish between large and small spills where the spill volume has a significant impact on the hazard. A cupful and a drum are not the same event.

6.1 — two readers, two answers

6.1.1 For non-emergency personnel

This is written for a person with no training, no suit and no plan, and the EU text gives them three things: protective equipment, control of the room — ignition sources, ventilation, dust — and emergency procedures.

The third is the one authors flinch from. Evacuating the danger area is a listed, compliant answer, and for many products the only honest one to give an untrained bystander. A sheet that instead sends them for absorbent granules has told them to stay in the room.

One clause is easy to miss: control of dust appears in the EU list and not in the UN one. Where the product is a powder, the first action is to stop it becoming airborne — the opposite of the sweeping reflex, and the reason vacuuming appears later in 6.3.2.

6.1.2 For emergency responders

One sentence, and it is about material. Advice shall be provided related to suitable fabric for personal protective clothing, and the Annex prints its own worked example as a pair: appropriate, butylene; not appropriate, PVC. UN GHS Annex 4 gives the same example.

This is narrower than it looks, and it is not a duplicate of section 8, which specifies protection for routine work at or below an exposure limit — glove material, thickness, breakthrough time. Subsection 6.1.2 is about the garment worn by someone standing in the release, and it asks for a compatibility statement in both directions: which fabric holds, and which fails. A responder can reason from that to the suit they own. They can do nothing with “wear suitable protective clothing”.

6.2 — the drain is the shortest way off site

Environmental precautions get their own numbered subsection in the EU and UN texts, and both name the same example: keeping the release away from drains, surface and ground water.

OSHA’s Appendix D has no such item — Table D.1 gives section 6 two lettered entries, and neither is environmental. As with environmental exposure controls in section 8, releases to water and soil belong to the EPA, not to OSHA. A US-only sheet with no 6.2 is not defective under HazCom. The same sheet supplied into the EU is.

Where 6.2 goes wrong is by collapsing into a label element. P273 — avoid release to the environment — states the objective, not the precaution. The subsection asks what to do, and what it says must agree with the aquatic toxicity in section 12.

6.3 — contain first, then clean up

The EU text splits this into two obligations that are easily read as one, and the order is operational rather than editorial.

6.3.1 covers containment, and names two techniques: bunding with covering of drains, and capping procedures. UN GHS Annex 4 defines a bund in a footnote — a liquid collection facility that, in the event of a leak from tanks or pipework, captures well in excess of the volume of liquid held, draining to a capture tank with water/oil separation. That definition carries a dependency: a bund is built before the spill, not improvised during it. If section 7 never asked for one, 6.3.1 has nothing to invoke.

6.3.2 covers clean-up, as a menu of six categories. The last of them — the equipment required — carries its own instruction: include the use of non-sparking tools and equipment where applicable. That is the reason 6.1.1 tells a bystander to remove ignition sources. A spill of a flammable liquid is a fire that has not started yet, and the tool used to clear it is a candidate source.

The Annex names categories, not products. Which absorbent and which neutraliser are the supplier’s judgement, exactly as the extinguishing medium is in section 5.

6.3.3 — the subsection that exists for the word “never”

Subsection 6.3.3 asks for any other information relating to spills and releases, including advice on inappropriate containment or clean-up techniques, and the EU text prints the phrasing it expects: an indication like “never use …”. UN GHS Annex 4 states the same requirement without the worked phrasing; OSHA has no counterpart at all.

It is the direct twin of the unsuitable extinguishing media in 5.1, and it disappears for the same reason: authors list what works and stop. The default reflex is water, and for a substance classified as emitting flammable gases in contact with water, hosing the spill down is the failure mode 6.3.3 exists to prevent.

6.4 — a subsection made entirely of pointers

“If appropriate sections 8 and 13 shall be referred to.” That is the whole of 6.4 — the only subsection in the Annex whose content is a reference to other subsections rather than information about the product.

The two destinations are not arbitrary. Section 8 holds the detailed protective-equipment specification, so section 6 need not carry it twice. Section 13 holds disposal, because everything collected in 6.3.2 — saturated absorbent, sweepings, washings — is waste from the moment it is in a container. Neither Appendix D nor Annex 4 has this subsection, which is why 6.4 is often the first thing to go missing when a US sheet is adapted for the EU.

Leaving it blank is not an option: the Annex states that the safety data sheet shall not contain blank subsections. But the pointer only works if 8 and 13 hold what a responder needs.

How section 6 connects to the rest of the sheet

Section 6 is unusually dependent on its neighbours — one of its four subsections is nothing but links:

• Section 8 supplies the equipment detail 6.1.1(a) and 6.4 both defer to. Section 6 names the fabric for the responder; section 8 names the glove for the day job.
• Section 13 receives everything 6.3.2 collects. The handover is written into 6.4.
• Section 7 is where the bund and the drain cover should have been specified, before there was anything to contain.
• Section 5 shares the ignition-source logic and the non-sparking tools. A large spill of a flammable is a section 5 event waiting for a source.
• Section 12 makes 6.2 checkable: an aquatic hazard in 12 with no drain instruction in 6.2 is a contradiction inside one document.
• Section 9 supplies what every spill instruction assumes — relative density, water solubility, vapour pressure. Whether the release floats, sinks or evaporates decides which clean-up category applies.

What a good section 6 looks like

Three tests, all answerable by reading:

1. Can an untrained person act on 6.1.1 alone? Every instruction should be executable with what is already in the room, by someone who will not read section 8 first. If it needs equipment they do not have, it was written for the wrong reader.
2. Does 6.1.2 name a fabric — and a fabric to avoid? The Annex’s own example is a pair. One-sided advice tells a responder nothing about the suit they are standing in.
3. Does the section contain a “never”? 6.3.3 asks for the inappropriate techniques. A section 6 with no negative instruction came from a template, not from the classification.