Liquid Chemical Products Sampling Code
The purpose of this Liquid Sampling Code (LSC) is to serve as a guide for the proper sampling and handling of liquid chemical products. There are certain procedures to be followed and certain precautions to be taken in order to ensure that the product is sampled in such a way as to preserve its identity and integrity, and to provide a valid representation of the lot or quantity from which it was taken.
It is most important to use proper sampling procedures to insure that samples taken are representative of the product received. Improper sampling can lead to errors in product analysis and, consequently, inaccurate and mischaracterized product specifications.
1. SCOPE
The LSC applies to all shipments and receipts of liquid chemical products.
2. SAMPLING EQUIPMENT
Adequate sampling equipment, including containers, pumps, meters, and filters, must be used and maintained in accordance with manufacturer’s instructions. Containers should be of a size and type certified for the product being sampled. Containers, pumps, and filters shall be of stainless steel, aluminum or other inert material which will not react with the product being sampled and which is inert with respect to ordinary atmospheric, microbiological, and chemical contamination.
The type, size and number of containers used to sample and transport the product should be appropriate to the requirements of the customer or regulatory body and other involved parties. The container should be fitted with an internal or external shut-off valve. Valves should be of stainless steel and must be impermeable to product leakage.
3. SAMPLE LOCATION
Samples for analysis shall be taken from the representative locations of the shipment. For example, for shipments of large tank loads, samples shall be taken from the middle and bottom of the tank or drums. For shipments of tank cars, one sample should be taken from the middle of the top section, one from the middle of the bottom section, and one from the top or bottom, whichever is nearer the inlet connection of the rail car.
4. SAMPLING PROCEDURES
All sampling methods should meet or exceed the applicable requirements of accepted industry or governmental agencies.
a) Proportional Sampling: This method divides the shipment into proportional streams or fractions in order to obtain an appropriate sample size. This is the most accurate method of assuring a representative sample.
b) Representative Sampling: Representative sampling involves taking a number of discreet samples from various points or depths within the shipment which, when combined, constitute a representative sample.
c) Depth Sampling: A depth sample involves taking grab samples from the top, middle and bottom of tanks, tank cars, containers or drums in order to obtain a sample of the entire contents.
d) Grab Sampling: This involves collecting a sample from the top of a supply or accumulation of a product at a single point in time.
e) Composite Sampling: Composite sampling involves collecting a number of grab samples from the top of a supply or accumulation at different points in time to obtain a composite sample of the product.
5. CONTAINERS
Samples for testing should be collected in containers which are durable, clean, and tight fitting, and of an appropriate type and size. These containers must be made of stainless steel, aluminum or other inert materials which will not react with the product being tested and which are inert with respect to ordinary atmospheric, microbiological, and chemical contamination.
The containers should be fitted with an internal or external shut-off valve and should be CLEARLY marked as “SAMPLE”. Containers shall be of a size and type certified for the product being sampled. All containers should be labeled with the product type and the date and time of sampling.
6. RECORD KEEPING
At least one container of a sample from each shipment and from each part of a shipment should be retained for record keeping. All other containers should be properly labeled, sealed and identified for storage or disposal. All samples should be stored in suitable containers under appropriate conditions until testing is completed and disposal can be effected in accordance with applicable regulations.
7. DISCLAIMER
This Liquid Sampling Code does not indicate that any parties involved in any shipments or receipts of liquid chemical products have any liability to third parties. The use of this Code does not eliminate the need for compliance with all applicable laws and regulations.
8. CONCLUSION
The Liquid Sampling Code outlines the basic procedures to be followed when sampling and handling liquid chemicals. Careful adherence to these procedures is necessary in order to ensure that the samples taken are representative of the product received. Furthermore, proper record keeping is required in order to ensure that samples are stored or disposed of in accordance with applicable laws and regulations.
