Purchasing activities are described in Procurement Policy (p. 4). I chose No based on this mention in methodology:

"Please note that statements might refer to "responsible purchasing practices" to make general statements about their engagement strategy with suppliers. It does not automatically mean that they meet the criteria for this metric. Companies should explain what they are doing to ensure responsible purchasing practices"

I did not find any concrete examples of responsible purchasing practices.

p.4,5

Procurement Policy - The organisation is committed to conducting purchasing activities in a fair, objective, and transparent manner that satisfies the requirements of accountability and internal controls including but not limited to NHP’s ‘Quality Management’, ‘Environmental’, ‘Ethical Code of practice’, and ‘Anti-Bribery’ policies which fulfil legal and financial obligations and effectively manages commercial risk. Emphasis is placed on selecting suppliers and service providers that demonstrate recognisable environmental, sustainable, business integrity along with Corporate Social Responsibility (CSR) standards including but not limited to compliance with laws and regulations, respect for human rights, labour working conditions, equal opportunities, health and safety accreditation, maintenance and promotion of information security, fair trade, and acceptable corporate ethics."

In this case, the company imposes standards on the suppliers, but it does not question/change its purchasing behavior when it comes to negotiating prices, delivery times, even though those factors can increase the risk of modern slavery.