Health and Safety Directorate

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Waste Water - Trade Effluent


There are 4 types of waste water produced by Queen Mary University of London (QMUL), which will either be disposed of to the sewer or leave site as hazardous waste.

  • Normal waste water from sinks, toilets, etc.
  • Surface water runoff from rain falling on the ground and buildings (this is the reason that the management of spills is important).
  • Trade effluent waste generated from certain operations including commercial research.
  • Laboratory wastes associated with publically funded research and teaching.

This web page details how the final two waste water streams should be managed and whilst our water discharge permits only apply to commercial research we apply the same standard to all waste water arising from laboratories and similar.

The guidance is divided into the following sections

  • What  chemicals must not be disposed of down the sink
  • What can be disposed of down the sink
  • How to dispose of wastes down the sink
  • QMUL procedures, permits (campus specific) and guidance posters
  • References
  • FAQs

What can be disposed of down the sink?

Aqueous chemical solutions can be disposed of down the sink provided:

  • Chemicals are dilute and below relevant hazardous waste threshold level(s).
  • Chemicals are not on the ‘Red List’ of chemicals that should never be disposed of down the sink through the sewerage system.
  • They are not excluded on the permit for the specific campus.

It is recognised that research labs will generate small volumes (a few hundred millilitres) of relatively innocuous chemical solutions that would no longer be classed as hazardous following moderate dilution.  As such, it is acceptable for solutions of small volumes (typically <500 mls) of non-toxic water soluble chemicals to be carefully washed down the sink with plenty of running water.

The assessment of what is a 'small amount' relies on professional judgement, bearing in mind the concentration levels at which the substance(s) are toxic or otherwise harmful.

Larger quantities or highly concentrated chemical substances must not be put down the drain but must be disposed of via QMUL hazardous waste disposal route (insert the link).

Examples of low hazard, water soluble waste includes:

  • Diluted acids, alkalis and alcohol's
  • Harmless inorganic salts (including drying agents  such as CaCl2, MgSO4, Na2SO4, P2O5)
  • Alcohol's containing salts (e.g. from destroying sodium)
  • All disinfectant solutions used to inactivate Hazard Groups 1 and 2 biological agents
  • Hypochlorite solutions (e.g. from destroying cyanides, phosphines)

If you are in any doubt whether a solution can be put down the sink contact your Faculty Health and Safety Manager/Adviser “Link to contacts”.

What chemicals must not be disposed of down the sink?

No waste substances should be put down sinks that could ultimately harm:

  • The environment
  • The sewerage system
  • The health and safety of the public or have the potential to interact with other substances to cause such affects
  • However, it is acceptable for waste solutions from experiments containing trace / low levels of hazardous organic or water miscible chemicals to be disposed of via the sinks, but must be flushed with plenty of water (see ‘what can be disposed of down the sink?’)

What chemicals must not be disposed of down the sink?

As a general principle, certain wastes are considered unacceptable for discharge to drain via sinks.  These include:

  • Persistent chemicals  such as heavy metals and various organic compounds
  • Water immiscible organic liquids such as petroleum hydrocarbons and chlorinated compounds
  • Compounds which produce toxic vapours, such as cyanide, ammonia, formaldehyde and glutaraldehyde
  • Strongly acidic or alkaline wastes
  • Highly reactive chemicals or flammable wastes
  • Mercury compounds
  • Materials listed in the permit.

There are certain waste chemicals that SHOULD NEVER be disposed of down the sink into the sewerage system. This ‘Red List’   is taken from the UK Trade Effluent Regulations 1989.

QMUL procedures, copies of the permits (campus specific) and guidance poster for laboratory sinks.

References & Terms

To be added as relevant references and terms are identified


To be added as relevant questions received

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