Noise pollution is one of the common physical harmful factors in many work environments. The current study aimed to assess personal and environmental sound pressure level and project the sound-Isosonic map in one of the Razavi Khorasan Paste manufacture using Surfer V.14 and Noise at work V.5.0. This cross-sectional, descriptive study is analytical that was conducted in 2018 in the Paste factory that contains Canister, production and Brewing unit. Following ISO 9612:2009, Casella Cel-320 was used to measure personal sound pressure level, while CEL-450 sound level meter (manufactured by Casella-Cel, the UK) was employed to assess environmental sound pressure level. Statistical analyzes was done using SPSS V.18 and Linear Regression test. The sound-isosonic maps were projected using Surfer V. 14 and Noise at work V.5.0. The results of assessing personal sound pressure level indicated that the highest received dose (172.21%) and personal equivalent sound level (87.36 dBA) were recorded for workers in the Canister unit. According to results of measuring of the environmental sound pressure level, out of 16 measurement stations in this unit, overall 87.5% were regarded as danger and caution areas. The lowest and highest sound pressure levels in this units were 61 dBA and 92 dBA that belong to Brewing and Canister units respectively. Results indicate Over 75% of the Canister and production units had a sound pressure level greater than 85 dBA and these two units were regarded as the most dangerous area in terms of noise pollution. It is therefore necessary to implement noise control measures, apply hearing protection program and auditory tests among workers in these units
