A South Oxhey care home has been told that "action is needed" after it failed four out of six areas of care.
Turning Point - Timberlea, in Redwood Close, was visited by Care Quality Commission (CQC) inspectors on February 7 and 8.
The CQC report revealed that improvements needed to be made in the areas such as the care and welfare of those who use services and in safeguarding people from abuse.
Staffing and nutritional needs also required improvement.
The home provides personal care to 12 adults with learning disabilities and mental health conditions in a supported living environment.
The report revealed that: "Safeguarding arrangements were not effective, procedures were not always followed and concerns raised were not always acted upon. This meant that service users were at increased risk of being subject to abuse."
It continued: "Nutritional arrangements were not adequate, people were not supported to ensure food was in date and suitable for their needs. This meant that people were at increased risk of eating something which may have made them unwell."
The inspection was unannounced and routine.
Inspectors discovered that staff "were not adequately supported" as there was not enough regular supervision and that mandatory training was overdue for most staff.
People at the home were said to comment on how staff "were nice and would help them if they needed help".
However, some residents said that there was "not much for them to do" unless they went to the daycentre or shopping.
The report stated that: "One person who lived in their own flat told us that they did not see staff except to receive their medication and that they were unable to go out without support. This meant that on the days they were at home they were frequently there all day on their own."
Care plans were found not to have been reviewed and updated regularly enough and mental health needs were "not adequately" documented for all of the people.
Inspectors added: "We also saw on an incident report form that one person had been admitted to hospital with dehydration. This person did not have a care plan in place and there was nothing recorded in their file or risk assessment to minimise the risk of this occurring in the future."
The carehome was found to meet the standards of supporting workers and complaints policy.
Davinder Jhuty, Turning Point spokesman, said: “Ensuring safe, person centred care for the people we support is our main priority and we take the issues raised by the recent CQC inspection very seriously.
“We took immediate action to address all areas highlighted by the inspector however we feel strongly that the experience and safety of individuals living at Timberlea was at no point compromised.
“We continue to work closely with our commissioners, Hertfordshire County Council, the CQC, people living at Timberlea and their families to provide high quality support to help residents live as independently as possible.”