Spray polyurethane foam (SPF) insulation has been reported to emit hazardous compounds if not applied correctly. Because two-component low-pressure spray foam insulation is more readily available for a do-it-yourself project in homes, the importance of optimal application is getting attention. We compared chemical emissions from spray foam insulations applied in four different ways in an attempt to simulate normal and abnormal applications. The normal application (SPF1c) involved adhering to the manufacturer's application instructions and assumed identical amounts of Components A and B (1 : 1) and a final foam thickness of 2 in. in two passes applied at room temperature (22–23°C). The Component A opening was reduced to a quarter turn in attempt to achieve a 0.25 : 1 ratio with the intention of generating a nonoptimal ratio of two components in the next application (SPF1d). SPF1e and SPF1f were applied at 16 and 5°C, respectively, which are suboptimal compared to the recommended application temperatures of 21 to 32°C. After application, the specimens were tested for 4 days in 50-L chambers at 23°C, 50 % relative humidity, and 1 air change per hour. In general, the emission factors were higher if the foam was applied below the manufacturer's recommended application temperature. More specifically, the emission factor was the highest when the foam was applied either at 5°C for the most volatile organic compounds (VOCs) or at 16°C for some VOCs, followed by SPF1d. For example, the emission factor of triethyl phosphate increased by a factor of 2, 8, and 12 for SPF1d, SPF1e, and SPF1f, respectively. This demonstrates that the VOC emissions can increase significantly when the spray foam is not applied according to the manufacturer's application instructions.