Royal & Sun Alliance has updated its charity trustee insurance cover to include pollution coverage.
The pollution cover provides legal expenses up to £100,000 to defend criminal or regulatory proceedings relating to "pollution arising from a wrongful act".
It is one of several changes the insurer has made to its trustee insurance package in order to make it more relevant to the risks facing modern charities.
The definition of an insured person now includes any employee of the charity now working in a managerial or supervisory capacity. Retired and former trustees are protected for a further year if current trustees do not renew the contract.
Cover for loss caused by any dishonest, fraudulent or malicious act of a trustee, or by any loss of documents, has increased from £25,000 to £50,000.
Nigel Salisbury, practice leader at the company, said: "A worrying number of charities are not protecting themselves against the accidental or rogue actions of their trustees."