Text For Citation: 01 Item/Group: 001B Hazard:

29 CFR 1910.1000(a)(2): Employee(s) were exposed to an airborne concentration of carbon monoxide listed in Table Z-1 in excess of the 8 hour Time Weighted Average concentration of 50 PPM: (a) Block House: On or about October 13, 2020 an employee (Block House Manager) was exposed to carbon monoxide (CO) at a mean calculated 1156.7 ppm CO level (SAE = 0.146). The %COHb in the employee's blood reached a calculated peak level of 39.4%. Atmospheric pressure, height, weight, activity levels, tobacco smoking behavior, and other factors were taken into account. The 8-hour TWA exposure was 144.6 ppm CO ( SAE = 0.092), which is 2.89 times the OSHA PEL of 50 ppm CO. An SAE of 0.092 is applicable for the following dose-related exposures: The calculated dose was 69399.6 ppm CO-minutes. The effective half-life of CO after exposure was 263 minutes. The calculation assumed 21.0% O2 during exposure. 21.0% O2 after exposure. (b) Block House: On or about October 13, 2020 an employee (Block Machine Operator) was exposed to carbon monoxide (CO) at a mean calculated 672.9 ppm CO level (SAE = 0.141). The %COHb in the employee's blood reached a calculated peak level of 24.9%. Atmospheric pressure, height, weight, activity levels, tobacco smoking behavior, and other factors were taken into account. The 8-hour TWA exposure was 84.1 ppm CO ( SAE = 0.118), which is 1.68 times the OSHA PEL of 50 ppm CO. An SAE of 0.118 is applicable for the following dose-related exposures: The calculated dose was 40376.5 ppm CO-minutes. The effective half-life of CO after exposure was 308 minutes. The calculation assumed 21.0% O2 during exposure. 21.0% O2 after exposure. (c) Block House: On or about October 13, 2020 an employee (Maintenance Assistant) was exposed to carbon monoxide (CO) at a mean calculated 361.1 ppm CO level (SAE = 0.097). The %COHb in the employee's blood reached a calculated peak level of 26.0%. Atmospheric pressure, height, weight, activity levels, tobacco smoking behavior, and other factors were taken into account. The 8-hour TWA exposure was 90.3 ppm CO ( SAE = 0.095), which is 1.81 times the OSHA PEL of 50 ppm CO. An SAE of 0.095 is applicable for the following dose-related exposures: The calculated dose was 43331.7 ppm CO-minutes. The effective half-life of CO after exposure was 308 minutes. The calculation assumed 21.0% O2 during exposure, 21.0% O2 after exposure, and 24 % O2 for the 10 minutes just prior to sampling. (d) Block House: On or about October 13, 2020 an employee (Maintenance Technician) was exposed to carbon monoxide (CO) at a mean calculated 651.2 ppm CO level (SAE = 0.137). The %COHb in the employee's blood reached a calculated peak level of 21.2%. Atmospheric pressure, height, weight, activity levels, tobacco smoking behavior, and other factors were taken into account. The 8-hour TWA exposure was 81.4 ppm CO ( SAE = 0.106), which is 1.63 times the OSHA PEL of 50 ppm CO. An SAE of 0.106 is applicable for the following dose-related exposures: The calculated dose was 39070.6 ppm CO-minutes. The effective half-life of CO after exposure was 352 minutes. The calculation assumed 21.0% O2 during exposure, 21.0% O2 after exposure, and 24 % O2 for the 10 minutes just prior to sampling.