Hazardous waste submissions in Digital Waste Tracking (DWT) require additional data fields that do not apply to standard waste. This article covers what DEFRA requires for hazardous waste records, where to configure each field in Weighsoft, and how to resolve the most common failure errors.
This article applies to customers using the Weighsoft Hazardous module or submitting waste classified with a Hazardous (Z) activity code.
HP codes (Hazard Property codes)
HP codes classify the hazardous properties of waste — for example, HP3 (Flammable), HP6 (Acute Toxicity), or HP14 (Ecotoxic). DEFRA requires at least one HP code on every hazardous waste DWT submission.
Where to set HP codes
HP codes are set at the hazardous order item level, not on the product record:
Open the hazardous job or order containing the item.
Select the relevant hazardous order item.
Locate the HP Codes section and add the appropriate HP code(s) for the waste type.
Save the item. The codes will be included in the next DWT submission for that job.
If the HP code field is missing or the submission fails with an HP-related validation error, verify that the product's activity code is set to Z (Hazardous) in Lookups > Products.
Source of components
DEFRA requires a 'Source of Components' value when hazardous component data is declared in a submission. If this field is blank, the submission will fail or default to 'NOT PROVIDED', which DEFRA may reject.
Where to set Source of Components
For standard products: set in Lookups > Products > select product > DEFRA Source of Components field.
When using the hazardous module: set at the hazardous order item level, in the components section of the item.
The item-level setting takes priority over the product-level setting when both are present.
Component concentration data
Where hazardous waste components are declared, DEFRA may require concentration values for each component. These are entered in the components section of the hazardous order item.
Open the hazardous order item.
Navigate to the Components section.
For each component listed, enter the concentration value in the designated field.
Save and resend the DWT record if it had previously failed.
If concentration data is not available at the time of submission, the record may still be accepted by DEFRA depending on the waste classification. Check DEFRA's API specification for the specific rules that apply to your waste type.
POPS (Persistent Organic Pollutants)
If the waste contains Persistent Organic Pollutants (POPS), this must be declared in the DWT submission. DEFRA requires both the presence of POPS to be flagged and the Source of Components to be set.
Where to configure POPS
For standard products: go to Lookups > Products > select product > POPS tab. Enable POPS and complete the required fields.
When using the hazardous module: POPS can be configured within the Components section of the hazardous order item.
POPS configuration must be combined with a valid Source of Components value. A submission with POPS declared but no Source of Components will fail DEFRA validation.
Common hazardous DWT failure errors
Error / symptom | Likely cause | Where to fix it |
HP code validation error or missing HP code | No HP codes set on the hazardous order item | Open the hazardous order item and add the appropriate HP code(s) |
Component source defaults to 'NOT PROVIDED' | Source of Components field is blank on both the product and order item | Set Source of Components on the product in Lookups > Products, or on the hazardous order item |
POPS-related rejection | POPS flagged but Source of Components missing, or POPS not configured on product/item | Ensure POPS is configured on the product or hazardous order item and that Source of Components is also set |
"wasteItems[x].physicalForm must be one of [Gas, Liquid, Solid...]" | State field blank on the product, or system on pre-5.544.6 | Set State on the product in Lookups > Products. Upgrade to 5.544.6+ to resolve the version-specific cause. |
Submission fails with no specific error detail | Multiple missing fields or a general DEFRA API rejection | Check the Failed Reason tab on the individual DWT record for the full DEFRA error payload. Contact Support if the error is not covered in the DWT Message error codes article. |
Further resources
DWT: Which DEFRA fields are mandatory and which are optional
DWT Message error codes
Digital Waste Tracking (DWT) Setup & Settings
DEFRA API Specification: https://defra.github.io/waste-tracking-service/production/apiSpecifications/