Description of PAS 100:2018 2018

This Publicly Available Specification (PAS) specifies requirements for the process of composting, the selection of input materials, the minimum quality of composted materials and the storage, labelling and traceability of compost products. It specifies requirements for a Quality Management System (QMS) for the production of composts to ensure they are consistently fit for their intended uses. It also requires a Safety and Quality Control System, including Hazard Analysis and Critical Control Point (HACCP) assessment, which the composter takes into account when developing, implementing and reviewing the QMS.

NOTE 1 HACCP assessment identifies relevant hazards and establishes critical control points and critical limits for ensuring that any risks associated with product use are controlled within acceptable limits.

This PAS is for composts from a composting system into which only source segregated biowastes (see 3.66 and 3.9) and/or biodegradable non-waste materials are fed.

Inputs to the composting process are allowed to include digestate (whole digestate, separated fibre or separated liquor) from an anaerobic digestion facility that processes only source-segregated biowastes and/ or biodegradable materials as inputs, that is compliant with PAS 110 (see 5.1.6 and its notes).

Digestate (whole digestate, separated fibre or separated liquor) from a non-PAS 110 anaerobic or aerobic digestion process is only allowed to be added to a PAS 100 composting process if the digestate is made only from input materials allowed by PAS 100 (see 5.1.6 and its Notes).

NOTE 2 See [c] in bibliography, section “References to documents that are not legislation”. If in future PAS 110 includes Thermophilic aerobic digestion (TAD) (see 3.74) within its scope and the digestate from such a process complies with PAS 110, the digestate would be an eligible input material to a PAS 100 composting process.

NOTE 3 Attention is drawn to legislation that controls the use of digestates and the digestion process facilities that produce them (see 5.1). The production quality management and direct use of digestates in soil conditioning and other applications is specified in PAS 110:2014, where they are made using an anaerobic digestion process.

This PAS allows a composting process to utilize thermophilic aerobic digestion (TAD, see 3.74) for its sanitization step instead of aerobic composting (see Clause 7 Table 1) and the resulting compost can be claimed compliant with this PAS if all requirements are met. However, any whole digestate or separated liquor output arising from the TAD step that is not utilized in a subsequent aerobic composting step to form compost (see 3.17) is not allowed to be claimed compliant with this PAS.

NOTE 4 Requirements for the minimum quality of composts specify upper limits for human and animal pathogen indicator species, potentially toxic elements, microbial respiration rate (stability), physical contaminants, stones, and weed propagules. They also specify minimum plant response in a germination and growth test.

This PAS does not specify tests for specific or indicator plant pathogens due to a lack of validated methods.

NOTE 5 Annex B provides recommendations on composting temperature, moisture and duration that indicate a composting environment that can eradicate plant pathogens. It also includes reference to the Food and Environment Research Agency’s Code of practice for the management of agricultural and horticultural waste [k] and the European and Mediterranean Plant Protection Organization’s Guidelines for the management of plant health risks of biowaste of plant origin [l].

PAS 100 is applicable to product-oriented composting processes and the composter is responsible for establishing and consistently fulfilling any additional quality needs the customer has.

Vermi-composting is within the scope of this PAS where it follows a sanitization step of thermophilic aerobic composting or TAD (see 6.3).

PAS 100 does not apply to composting activities that do not require registration with the regulator, such as composting at home.

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