This document has been superseded and the new version can be found https://stacks.cdc.gov/view/cdc/175037 : NIOSH researchers conducted a field survey at Veterinary Hospital E in November 2017. The purpose of the site visit was to identify and evaluate hazardous drug engineering controls as well as to sample for potential surface contamination at the hospital. NIOSH researchers also observed and interacted with the hospital's veterinarians and staff to obtain information about the hazardous drug work practices, daily activities, and oncology treatment processes. A TSI VelociCalc(TM) Plus Model 9565-P thermal anemometer was used to measure air velocities at the face of the externally exhausted Class I 3971201 biological safety cabinet (BSC), while a Wizard Stick handheld smoke generator was used to visualize air movement inside and around the periphery of the BSC. The average face velocity of the BSC was 0.66 m/s (129 fpm), which is above the minimum recommended face velocity (i.e., 0.38 m/s [75 fpm]) for a Class I BSC. The qualitative test on the BSC using a Wizard Stick handheld smoke generator indicated good capture efficiency. The air changes per hour (ACH) of the main room (including open office area) was calculated from the supply rate to be 9, which meets the minimum 4 ACH for a human patient room. The ACH of the infusion room was calculated from the supply rate to be 5, which also meets the minimum 4 ACH for a patient room. The ACH of the anteroom was calculated from the supply rate to be 101, which meets the required 12 ACH for an unclassified containment segregated compounding area. The ACH of the buffer room was calculated from the supply rate to be 81, which also meets the required 12 ACH. The presence of potential surface contamination was evaluated with wipe samples. These were collected in areas where the staff handled chemotherapy drugs, such as the oncology department. Wipe samples were also collected in less obvious places (i.e., telephone, door handles) to determine if current workplace safety practices at the hospital were adequate to prevent inadvertent contamination of these surfaces. Sampling and analytical procedures varied by the hazardous drug for which they would be evaluated (i.e., the analyte). In some cases, a single sample could be evaluated for more than one analyte simultaneously. Vincristine and mustargen were the drugs used during the NIOSH visit. Sample analyses results revealed that 7 of 7 wipe samples submitted for toceranib analysis (an observed patient was on toceranib) tested positive (0.6 to 2.6 ng). Nine of 9 samples submitted for N-methyldiethanolamine (MDEA) analyses were also positive (3.9 to 21.2 ng) while simultaneously being non-detectable (ND) for lomustine and chlorambucil. MDEA was monitored as a potential stable marker for the highly unstable antineoplastic drug mustargen as explained in the text. The ND determination means that contamination was either not present, or was present at levels below the detectable limit of the analytical method. Four out of 5 wipe samples submitted for carboplatin were positive (4.2 to 11 ng/sample). These four samples were between the limit of detection (LOD) and limit of quantification (LOQ). Five out of 18 samples submitted were positive for cyclophosphamide (1.7 ng/sample), vincristine (9.9 to 71 ng/sample), and epirubicin (4.3 ng/sample) while simultaneously being ND for methotrexate and doxorubicin. Although some of the wipe sample analytical results were ND, there is no safe level of exposure when handling hazardous drugs. The epirubicin, carboplatin, vincristine, cyclophosphamide, MDEA, and toceranib presence serves as two reminders: (1) that hazardous drug contamination can sometimes linger despite cleaning efforts and (2) the detected contamination on desk and cabinet surfaces one might ordinarily think of as "safe", emphasizes the importance of proper work practices regarding the use of gloves and shoe covers, hand washing, and food/drink prohibitions within the hazardous drug handling environments. Therefore, it is important to continue to use engineering controls (e.g., biological safety cabinets), supplementary controls (e.g., closed system drug-transfer devices), protective work practices (e.g., surface cleaning after every oncology patient, regardless of whether I.V. chemotherapy was administered), and personal protective equipment (e.g., gloves and gowns rated for chemotherapy protection, respirators, shoe covers, eye protection) to reduce unintentional exposures to the staff or pet owners.