Transfers from Portable Containers

The employer is not required to label portable containers into which hazardous chemicals are transferred from labeled containers, and which are intended only for the immediate use of the employee who performs the... 

The quantity of flammable or combustible liquids, kept in the vicinity of spraying operations, is to be the minimum required for operations and should ordinarily not exceed a supply for one day or one shift Bulk storage of portable containers of flammable or combustible liquids are to be in a separate, building detached from other important buildings or cut off in a standard manner. Whenever flammable or combustible liquids are transferred from one container to another, both containers must be effectively bonded and grounded to prevent the discharge of sparks of static electricity. 

Most of the cryogenic fluids are now available commercially in many parts of the world. These are shipped and stored in special insulated containers from which they are either used directly or are transferred to portable dewars and used as required. However, liquid helium and some of the reactive fluids are ordinarily produced in laboratory liquefiers as they are needed. For simplicity, laboratory experiments may be conducted with these fluids directly in the liquefier storage vessel, although provisions are usually made for the withdrawal of the liquid through an evacuated transfer tube. 

OSHA says that immediate use means the chemical in the portable container can only be used by the employee who transfers it from a labeled container and must be used on that work shift. 

If employees transfer chemicals from a labeled container to a portable container that is intended only for their immediate use, no labels are required on the portable container. 

In-plant containers of hazardous chemicals must be labeled, tagged, or marked with the identity of the material and appropriate hazard warnings. Chemical manufacturers, importers, aud distributors are required to ensure that every container of hazardons chanicals they ship is appropriately labeled with such information and with the name and address of the producer or other responsible party. Employers purchasing chemicals can rely on the labels provided by their suppliers. If the material is subsequently transferred by the employer from a labeled container to another container, the employer will have to label that container nnless it is snbject to the portable container exemption. See paragraph (f) for specific labeling reqnirements. 

OSHA did not modify its previous exemption under the Hazard Communication Standard with regard to labeling of portable containers. Where hazardous substances are transferred from a labeled container into a portable container, used within a work shift, and under the control of the employee who performs the transfer, no labels are required on the portable container. However, if the chemical transferred to a portable container is not used within a work shift and under the control of the employee who performs the transfer, then labeling is required. 

Thomerson and Billings [87] describe field tests in which chlorine was released at up to 70kg min from three 1-ton containers. Typical wind velocities were about 9 m s . Relative humidity was very low, the test site being located in the Nevada desert. It is noteworthy that the temperature of the spilled liquid stabilized at about -50 C, well below the boiling point of —34°C. The wind subcooled the liquid, which was collected in a well-insulated pan, and approximately 50% of the chlorine vaporized during a test. The use of downwind water sprays in these tests reduced the concentration of chlorine in the air by an average of 31%. This was attributed to the induction of dilution air by transfer of momentum from the spray. As noted above, the spray also forced the vapor cloud lower, so that the concentration of chlorine at 1.5 m elevation was actually higher for a distance of 230 m fi om the point of release. In these tests, portable fire water monitors performed relatively poorly. 

A total of six tests was performed. Each involved transferring liquid chlorine from one or more 1-ton chlorine containers to the open pan. After the pool of liquid chlorine had stabilized, measurements were made of downwind concentration with no mitigation procedure applied. Then one of several different mitigation procedures was performed on the liquid pool. In the first and last tests, the only mitigation technique used was water spray nozzles to knock down the chlorine vapor cloud. In tests 2, 3, and 5, different vapor suppression foams were applied to the liquid pool surface in combination with water spray from the nozzle system and measurements were made of the downwind concentration to determine the effectiveness of the procedure. Test 4 used no foam but did use the water spray nozzles and portable water nozzles. 

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