ZSL is committed to ensuring that its vision is reflected in the suppliers with whom it does business, and in the products and services it procures. 

In addition to complying with all applicable statutory and legal requirements, ZSL’s suppliers[1] must comply with Ethical and Environmental Commitments set out in this Code as an absolute minimum, and take reasonable steps to ensure that those with whom they have a business relationship do likewise. ZSL will work with suppliers to help address non-compliance but reserves the right to terminate its relationship with a supplier in the case of breach of this Code. ZSL keeps this Code under ongoing review and may amend or add to this Code at any time.

Ethical Commitment 

Suppliers must respect the fundamental labour rights set out in the eight International Labour Organisation core conventions and ensure that working conditions of all employees including those employees along the supply chain are of an acceptable standard and, where possible, be externally verified. Key principles of these conventions as they relate to working practices are set out within the Ethical Trading Initiative Base Code, in summary as follows:[2]

  • employment is freely chosen
  • freedom of association and the right to collective bargaining is respected
  • working conditions are safe and hygienic
  • no child labour
  • working hours are not excessive
  • no discrimination is practised
  • regular employment is provided
  • no harsh or inhumane treatment
  • living wages are paid (enough to meet basic needs and provide some discretionary income)[3
  • Suppliers must respect the rights set out in the International Bill of Human Rights[4]
  • Suppliers must comply with the Modern Slavery Act 2015

Environmental Commitment 

  • Suppliers must exercise environmental due diligence – that is take reasonable steps and make good faith efforts – to avoid causing or contributing to any adverse impact on the environment
  • Suppliers must demonstrate an on-going commitment to protect the environment and, appropriate to their size and circumstances, have in place policies and processes that enable them to identify, prevent, mitigate and remedy any actual or potential adverse effect on the environment they cause or contribute to through their activities and relationships
  • Suppliers must disclose to ZSL information on any adverse effect on the environment that has come to their attention both in respect of themselves and along their supply chain, including the names of suppliers associated with these risks, and any risk management plans that have been put in place. Such information must be provided both before contracting with ZSL, and during the contractual relationship, and within 14 days of the information having come to the supplier’s attention   

ZSL strives to conduct its operations with minimum impact on the environment and the Earth’s finite resources, and to provide benefits to society. Suppliers agree to commit to continuous improvement (and when asked, provide evidence) towards ensuring that their business, products and services, and those of their suppliers, are:

1.    Reducing energy consumption

  • Including energy efficiency ratings and efforts to reduce CO2e emissions.

2.    Reducing water consumption

  • Including water efficiency and efforts to reduce water consumption.

3.    Reducing waste production

  • Including products recycled content and recycling activities, reductions in waste to landfill, reductions in packaging and ability to re-use materials through end of life disassembly. 

4.    Reducing risk from hazardous materials

  • Including use of non-toxic materials and efforts to reduce pollution
  • Including evidence that natural products are grown with minimum use of pesticides, artificial fertilisers and herbicides and, where possible, providing certification.   

5.    Supporting biodiversity

  • Including how products and services are limiting their impacts on biodiversity.

6.    Reducing travel emissions

  • Including distance travelled and efforts to reduce CO2 emissions. 

7.    Increasing sustainable procurement and investment

  • Including efforts to reduce resource use from unsustainable sources and investment into sustainable practices and whole life cycle thinking. 
  • Including efforts to ensure natural products are from sustainable sources where the chain of custody is known and, where possible, providing certification. ZSL may request certification of sustainability standards for timber, fish, paper and palm oil and derivatives used and suppliers will be expected to provide these.
  • Including efforts to ensure all animal products, such as meat, farmed fish, poultry and eggs, are reared to the highest welfare standards and, where possible, providing certification.

Read our Supplier Code of Conduct

[1] any company, organisation or person involved in supplying goods or services to ZSL on a contractual basis, including consultants (but excluding employment relationships).

[2] the full code is available at; ZSL refers to this code for guidance purposes and emphasises that they represent basic minimum standards only

[3] a full definition is available at

[4] consisting of the Universal Declaration of Human Rights and the main instruments through which it has been codified (the International Covenant on Civil and Political Rights and the International Covenant on Economic, Social and Cultural Rights); for a list of these rights see: or