All front line Thames Valley Police officers are to be issued with controversial hoods to protect themselves from suspects who spit at or bite them.

The spit guards are designed to be placed over the heads of suspects and will only be used on people who have already spat at officers, or who are thought to be about to spit, and only when a suspect has already been handcuffed.

However, the hoods have been condemned by human rights charities including Amnesty International and Liberty for being "cruel."

The move comes after more than 300 officers reported being spat at since April 1 last year. 

Of these, 30 officers reported being exposed to blood-borne virus contamination risk as a result of fluid entering their mouth, nose, eyes or open wound.

The TVP health and safety policy requires officers to attend A&E after these incidents, because spitting bodily fluids such as blood and saliva can pose a risk of transmitting a range of infectious diseases including Hepatitis C.

Officers are set to receive guidance on how to use the controversial hoods "safely and effectively." 

When using a spit guard, officers need to monitor the suspect at all times, as well as explain the reason for its use.

Officers will also need to "maintain the dignity of the suspect" throughout the process.

The decision to introduce them was made jointly with Hampshire Police after a consultation.

David Hardcastle, Assistant Chief Constable Operations, Hampshire and Thames Valley lead on joint operations, said: "Spit guards are being introduced to help protect officers, other emergency services personnel and members of the public from this unacceptable and potentially dangerous behaviour.

"Our officers put themselves at risk every day and we want to ensure that they have the appropriate equipment to deal with the challenges they face.

"Everyone should be able to go to work without the possibility of being assaulted, including being spat at.

"The management team has listened to concerns raised by officers and the Police Federation, as well as taking on board recent recommendations from the National Police Chiefs' Council and have taken the decision to provide them to all front line officers across the Force."