Listing items with Hazmat declarations

[lubefinder]

Creating an offer for an item with the Inventory API.

If I include the regulatory section in the offer payload as follows

"regulatory": {
     "hazmat": {
            "statements": [
                "H412"
            ]
      }
}

Then I get an error

"message": "Hazardous material information incomplete. Your listing must include pictograms, hazardous statements and a signal word.",
            "parameters": [
                {
                    "name": "0",
                    "value": "Item.Regulatory.Hazmat"
                },
                {
                    "name": "1",
                    "value": "Hazmat Pictogram, Hazmat Signal Word"
                }
            ]

But my product does not have a pictogram or signal word. It only has a hazard statement.

If I try with

"hazmat": {
            "signalWord": null,
            "pictograms": [],
            "statements": [
                "H412"
            ]
        }

I get the same result. Anybody done this before?