Responding to a spilled solid

Purpose

To get a spilled powder into a closed container without any of it becoming air you then breathe, and without turning a spill you could have lifted into one you have to absorb.

When to use it

Any time a solid leaves the vessel it was meant to be in — a scoop that missed the boat, a jar knocked over, a crust broken off a cap, a smear tipped from a folded paper. It is the response the spill routine hands off to at its step 5, and it comes first when a spill is both solid and liquid, because the solid is the part that can still be lifted dry.

The two things this procedure exists to stop are the two reflexes people have: reaching for a brush, and reaching for a cloth and water.

Before you start

You should already have read the dust route and the wet clean-up rule on protecting yourself, and know which shelf group the substance belongs to from storage and incompatibilities.

Within reach: a stiff card or a dedicated scoop; a container with a lid that closes; one damp disposable wipe; a bag for the loaded wipe and the gloves; eye protection; new gloves, heavier than the ones you work in.

!One step of this procedure is Level B, and it is step 5

The session’s baseline is Level A. Lifting the solid is declared Level B where the powder is a concentrated alkali, a developing agent or silver nitrate, because that is the moment the substance can become an aerosol. The controls for that step, stated here rather than left to be inferred: chemical splash goggles that seal against the face rather than safety glasses; the card worked within a centimetre or two of the surface; and a mask rated for fine particulates where section 8 of the product’s own sheet asks for one. The course names no filter class of its own, and the protective equipment page says why.

Procedure

1. Stop, set down what you are holding upright, and say aloud what has spilled.
2. Still the air over the spill before you touch it. Shut the door, and stop any fan or draught that is blowing across the bench rather than drawing at the far end of the room.
3. Eye protection on, then new heavier gloves — not the pair you were weighing in.
4. Look at what it has landed on and what it has landed near. A solid that has reached an acid, a waste container, a tray of solution or a sheet of paper is a different problem, and the incompatibility matrix says which.
5. Lift the bulk dry. Card or scoop, worked slowly and close to the surface, straight into the container, and the lid on. Do not brush it: a brush is a machine for putting a spill into the air.
6. Take up what is left with one damp disposable wipe, in one direction, after the bulk has gone rather than instead of lifting it.
7. Wipe the surrounding half metre as well, including the bench lip and the front edge, because a fine solid travels further than the pile you can see.
8. Close the bag on the wipe and the gloves, and label it.
9. Route what you lifted. If it is clean and identifiable it may go back to its own jar only where nothing else has touched it; otherwise it is waste, in the container for its own stream. Where that means a disposal decision, the disposal caveat is the page that governs it and this procedure issues no instruction.
10. Take the gloves off by the removal sequence, into the bag, and wash your hands.
11. Write it down, and re-weigh if the spill came out of a batch you had already recorded.

How you know it worked

• Nothing was swept, and nothing was wetted before it was lifted.
• The container the solid went into has a lid on it and a label with today’s date.
• No film of powder remains on the bench lip, on the front edge or on the floor in front of you.
• Nothing has been left to dry on a surface or in an open bin.
• If the spill came out of a weighed quantity, the notebook says so and the mass has been taken again rather than assumed.

If a step fails

Step 2, the extract is the only thing keeping the room breathable and you cannot stop it. Leave it running and work from the upwind side, with your face out of the line between the spill and the fan. A draught across a spill is the problem; a draught away from you is not.

Step 5, you have already brushed it. It is airborne now. Leave the room, close the door, ventilate it from outside if you can do that from outside, and give it time before you come back in new gloves and eye protection. Do not carry on standing over it.

Step 5, the solid has gone damp and will not lift. It is deliquescent and has taken up water from the air, which also means the jar it came from can no longer be weighed against its label. Treat what is on the bench as a liquid spill, from step 6 of responding to a spill, and put the jar itself through the stock check.

Step 5, it is silver nitrate. Everything above applies, and three things are added: nothing goes into an open bin, nothing is left to dry, and all of it is collected. The differences are responding to a silver nitrate spill.

Step 6, you wetted it before you lifted it. You now have a liquid spill several times the volume of the solid. Carry on from step 6 of the general spill routine and expect to fill more absorbent than you thought you would need.

Step 9, you cannot say which stream it belongs to. Give it a container of its own, labelled with the date, the process and the word unidentified, and treat it as a container found unlabelled. Tipping an unknown into a labelled stream turns one unknown into a whole bottle of it.

What to record

What was spilled, roughly how much, where it landed and what it landed near. Then what you lifted, what you wiped, where each went, and whether a recorded mass has been invalidated. Finish with the one sentence that earns the entry: what put the solid in a position to fall.