Abstract: A method for preventing inhalation or ingestion of airborne aerosol particles of toxic or life-threatening materials by medical laboratory personnel wherein a portable safety shield is placed between the body of the laboratory personnel and a container of toxic or life-threatening material prior to opening. The container is opened behind the shield so that any airborne aerosols of the material cannot directly be inhaled or ingested by the laboratory personnel. The safety shield is an upright self-supporting body of a rigid transparent sheet material which comprises a horizontal base, wherein the body is inclined with respect to the base. Notches are provided in the body to facilitate access to the base.