Quick answer: Bin store cleaning in social housing is a COSHH-regulated activity involving biological agents including organic waste residue, bacteria and mould. The correct method is hot-water pressure washing at 70–90°C with a biological pre-soak and documented dwell time. Cold water alone redistributes contamination rather than eliminating it, and wash-water is trade effluent requiring correct drainage management.
Bin stores in social housing estates, tower blocks and local authority housing are among the most neglected cleaning tasks in facilities management. They are used daily by multiple occupants, frequently misused, and rarely cleaned to the standard the environment demands. For facilities contractors and DLOs managing housing stock across the Midlands and East Midlands, bin store cleaning sits in an awkward operational gap — too routine to attract management attention, too hazardous to treat as a standard outdoor cleaning task.
The contamination profile of a social housing bin store is not the same as a commercial waste area. Domestic waste includes food residue, nappies, soiled material, and general organic matter. In enclosed brick or concrete stores, this accumulates across the floor, walls, drainage gullies and the underside of wheeled bins. The result is a combination of:
- Organic waste residue — including partially decomposed food matter, liquid leachate from bin bags
- Bacteria — including coliforms from food and sanitary waste
- Mould — growing on wall surfaces and drainage infrastructure in poorly ventilated stores
- Fly and pest activity — particularly in summer months, compounding biological risk for operatives
Under COSHH Regulations 2002, biological agents are a category of hazardous substance. Cleaning operatives working in a contaminated bin store environment are working with biological agents whether or not a formal COSHH assessment has been completed. The absence of a risk assessment does not reduce the legal exposure — it increases it.
Cold water pressure washing is the method most commonly used on bin stores by contractors who have not reviewed the task against COSHH. It is also the least effective method for this environment. Cold water at high pressure disperses contamination — it moves it across the floor and into the drainage gully, but does not destroy the biological agents present. Odour returns within days. Fly and pest activity is not reduced. The operative is exposed to aerosolised contamination during the wash.
Hot water pressure washing at 70–90°C combined with a biological pre-soak is the correct method. The pre-soak — a biological detergent or enzymatic cleaner applied to all surfaces and allowed a documented dwell time of 8–10 minutes before washing — breaks down organic matter and begins the deactivation of biological agents before the hot water contacts the surface. The hot water stage then flushes, sanitises and deodorises in a single pass.
The practical outcomes of switching from cold to hot water with pre-soak are measurable: reduced wash time per store, significantly reduced odour recurrence, fewer contractor callbacks, and a method statement that is defensible under COSHH if an operative raises a health concern or an enforcement visit occurs.
Wash-water from bin store cleaning is not clean water. It contains the biological contamination removed from the surfaces — organic matter, bacteria, cleaning chemicals. Under the Environmental Permitting (England and Wales) Regulations 2016 and the Water Industry Act 1991, this wash-water is classified as trade effluent when it enters the surface water or foul sewer network.
For contractors, this has two practical implications. First, wash-water must not be directed to surface water drainage — which in most housing estates means it cannot simply be allowed to run off into the road or storm drains. Second, the drainage gully within the bin store should be connected to foul drainage. Where it is not — which is common in older housing stock — the contractor's method statement needs to address how wash-water is managed and contained.
Documenting drainage management as part of the method statement is increasingly expected by housing associations reviewing contractor compliance. It is also the correct position under the relevant legislation regardless of whether the client is asking for it.
A facilities contractor managing bin store cleaning across three tower blocks on a housing association estate in the East Midlands — 24 stores across the three blocks, each visited monthly — had been using a cold electric pressure washer. Each block has an enclosed external bin store with a concrete floor, brick walls, and a central drainage gully.
The result was superficially clean but odour and fly activity returned within two weeks. The housing association received complaints from residents and flagged it in their quarterly inspection report.
The contractor switched to a petrol hot water unit and added a biological pre-soak to the method. Dwell time before washing was set at 10 minutes. Wash-down time per store dropped by around 20% due to the improved release of organic matter. Odour complaints reduced to one across the following quarter. The housing association included the updated method statement in their contract renewal discussions as evidence of standard improvement.
The COSHH assessment for the operatives was updated to reflect the biological hazard classification of the waste environment, and PPE requirements — gloves, eye protection, waterproof overshoes — were documented as mandatory for bin store visits.
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