Aid agencies have welcomed last week's decision by nine banks - including Credit Suisse - to sign up to a new set of environmental guidelines.
However, they fear the so-called "Equator Principles", which apply to the funding of future development projects, may never be put into practice.
Caroline Morel, executive director of the Bern-based non-governmental organisation, Swissaid, conceded that the guidelines were a step in the right direction.
But she cast doubt on whether they were as big a breakthrough as they initially seemed.
"I think in general it's a good sign," Morel told swissinfo. "But there are a lot of questions still open, especially because it's not clear how the implementation will work. "
"We don't know about the monitoring mechanisms, and it's very important if you have some principles that you control them and can really prove that they are implemented," she added.
The Equator Principles, based on recommendations by the World Bank and the International Finance Corporation, are to be applied to all projects costing over SFr66 million ($50 million).
The guidelines state that the signatory bank must ensure potential candidates for funding can prove that their project meets certain criteria, including respect for the environment and indigenous communities.
Banks have come under criticism from aid organisations and environmental groups in the past for financing controversial projects such as oil pipelines, mines and dams, which have had a damaging effect on local biodiversity and people.
Among the other banks that have adopted these principles are Citigroup of the United States, Barclays in the United Kingdom, and Dutch bank ABN Amro.
In making their business practices more ethical, banks are also protecting their own reputations and, potentially, avoiding damaging lawsuits.
Bernd Schanzenbacher, who is responsible for environmental issues at Credit Suisse First Boston, says that by adopting the principles the bank will lessen the risk of litigation over any damage ensuing from projects it funds.
"Environmental risk is business risk, it's as simple as that," he told swissinfo. "So our ignorance of environmental risks can lead to costly litigation, but it can also lead to negative publicity and even revenue reduction."
Schanzenbacher also admits the principles have their limitations and don't offer a guarantee that all future projects won't damage the local area.
"Every economic activity has an impact on the environment, so there are no hard and fast rules on whether a project is sensitive or not," he said.
So far only ten banks have adopted the principles, although a further six are expected to join in the next few weeks, according to the World Bank.
Switzerland's largest bank, UBS, has not adopted the guidelines. When contacted by swissinfo, UBS spokesman, Serge Steiner, said the bank had not signed up to the Equator Principles because it is not involved in financing international projects.
swissinfo, Marie-Christine Bonzom and Karin Kamp
The Equator Principles are a set of voluntary guidelines based on the principles of the World Bank and the International Finance Corporation.
In adopting the principles, the ten banks pledge to ensure all development projects they fund in the future respect the environment and local communities.
Although NGOs welcome the Equator Principles as a step in the right direction, they criticise the lack of a monitoring process to ensure the banks adhere to the guidelines.