Codex sampling plans for prepackaged foods (aql 5) codex stan 233-1969 scope

The Sampling Plans in Appendix I of this document apply to the acceptance of defective units (defectives) in lots of prepackaged foods, as defined in individual Codex Standards, insofar as the Sampling Plans have been specifically included in such Codex Standards for the purpose of determining the acceptability or otherwise of the lot. They shall be used in accordance with the provisions dealing with the classification of defectives and lot acceptance in Codex Standards to which these Sampling Plans are stated to apply and within the limits of Section 2 of this document.

2.1. TYPE OF EXAMINATION TO WHICH THE SAMPLING PLANS APPLY

The Sampling Plans in Appendix I of this document are intended primarily to cover the quality provisions of Codex Commodity Standards where an AQL of 6.5 is appropriate for the defective unit as defined in Codex Standards. For the purposes of these Sampling Plans, “quality” refers to those factors or product characteristics which are evaluated by organoleptic or physical means, such as colour, flavour, texture, defects, size and appearance. They are not intended however, to cover factors which may represent a hazard to health or which are unwholesome or otherwise highly objectionable to the consumer on the basis of which responsible authorities would reject the lot. Examples of these latter categories are pesticide residues, contaminants, blown cans, foreign material such as stones and large insects. Other criteria andsampling plans must be used in dealing with factors of this type. While these Sampling Plans are intended primarily for quality evaluation, they may be found suitable for other determinations such as net weight, Brix values and drained weight, provided an acceptance criterion with an AQL of 6.5 is appropriate for these determinations. In this case a definition of “defective” for the specific determination under consideration would be required in the respective Codex Standard.
2.2. SIZE OF LOT AND POINT OF APPLICATION

The Sampling Plans and acceptance procedures contained in this document are designed to cover lots that represent substantial portions of factory production or relatively large blocks of merchandise. The plans may also be used for small lots, but Governments may elect to use sampling procedures of their own choosing for enforcement at the retail level. This is done in recognition of the high ratio of sample size to lot size when dealing with small lots and the probability that once the production of defective or non-conforming product is no longer likely to be uniform between and within the smaller lots.

For detailed explanation of the statistical basis for these Sampling Plans, see Appendix II of this document.

The Sampling Plans - Appendix I of this document - are a tabular presentation appropriate for acceptance sampling of prepackaged foods where an AQL of 6.5 has been accepted for certain products characteristics. The Plans include:

1. Inspection Levels;

2. Sample Sizes in relation to lot size and container size; and

3. Acceptance Numbers.

A sample is drawn at random from the lot according to the appropriate schedule in the Sampling Plans. Each sample unit is examined according to the requirements of the individual Codex Standard and classified as either “acceptable” or as “defective”. Based on the total number of “defectives “ in the sample, the lot either “meets” or “fails” the requirements of the Codex standard, to which these Sampling Plans apply, according to the following criteria:

- Meets if the number of “defectives” is equal to, or less than, the acceptance number of the appropriate plan.

- Fails if the number of “defectives” exceeds the acceptance number of the appropriate plan.

4.1. ACCEPTABLE QUALITY LEVEL (AQL)

The maximum percent defective units (defectives) permitted in a lot which will be accepted approximately 95 percent of the time. For example, a sampling plan at an AQL of 6.5 will accept a lot or production which has 6.5 percent defective approximately 95 percent of the time.
4.2. ACCEPTANCE NUMBER (C)

The number in a sampling plan which indicates the maximum number of defectives permitted in the sample in order to consider the lot as meeting the requirements of a Codex Standard.

4.3. BUYER’S RISK

The risk a buyer takes that a lot will be accepted on the basis of these Sampling Plans even though such a lot may fail to conform to the requirements of the Codex Standard.

The risk a producer takes that a lot will fail on the basis of these Sampling Plans even though such a lot in

reality may meet the requirements of the Codex Standard.

4.5. DEFECTIVE

A “defective” is a sample unit which does not conform with a certain specified requirement (or requirements) of a Codex Standard (on the basis of total “demerit points”, individual tolerances for “defects”, etc.). The criteria on the basis of which a sample unit is classified as “defective” are specified in individual Codex standards to which these Sampling Plans apply (see also Sub-sections 2.1 and 2.2 of this document). Although a defective is a sample unit which fails to meet certain specified requirements in Codex standards, it does so only to an extent which is slightly below those requirements and which would not make the product objectionable to the consumer as specified in Section 2 - Field of Application, Sub-section 2.1.

The process of measuring, examining, testing or otherwise comparing a container or unit of product (sample unit) with the requirements of a Codex Standard.

The term used to indicate the relative amount of sampling performed on lots of a given product or class of products.

Collection of primary containers, or sample units, of the same size, type and style which have been manufactured or processed under essentially the same conditions.

The number of primary containers, or sample units, in the lot.

The individual container (primary container), a portion of the contents of the primary container or a composite mixture of product that is examined or tested as a single unit

Any number of sample units which are used for inspection. Generally the sample comprises all of the containers or sample units drawn for examination or testing purposes from a particular lot.

The process of drawing or selecting containers or sample units from a lot or production.

The number of containers, or sample units comprising the total sample drawn from a lot or production.

A sampling scheme which includes sample sizes, inspection levels, acceptance and/or rejection numbers so that a decision can be made to accept or reject the lot or production based on the results of inspection and testing of the sample.

In using the Sampling Plans in Appendix I of this document, the following information shall be known:

1. 
   ontainer size (net weight in kg or lb)
   
2. 
   Inspection Level (see sub-section 4.7)
   
3. 
   Lot size (N) (see sub-section 4.9)
   
4. 
   Requirements of the Codex Standard with respect to product quality (i.e. classification of defectives and requirements for acceptance of the lot).
   

The following steps are taken:

1. 
   The appropriate inspection level is selected as follows:
   

Inspection Level II - Disputes (Codex referee purposes sample size), enforcement or need for better lot estimate.

2. 
   Determine the lot size (N), i.e. number of primary containers or sample units.
   
3. 
   Determine the number of sample units (sample size (n)) to be drawn from the inspection lot, consideration being giving to container size, lot size, and inspection level.
   
4. 
   Draw at random the required number of sample units from the lot giving proper consideration to code or other identifying marks in selection of the sample.
   
5. 
   Examine the product in accordance with the requirements of the Codex Standard. Classify any container or sample unit which fails to meet the specified quality level of the standard as a defective on the basis of the classification of defectives contained in the Codex Standard.
   
6. 
   Refer to the appropriate Sampling Plan in Appendix I.
   
7. 
   Consider the lot acceptable if the number of defectives is equal to or is less than the acceptance number (c) of the appropriate Sampling Plan contained in Appendix I of this document.
   
8. 
   Consider the lot as failing if the number of defectives exceeds the acceptance number (c) of the appropriate Sampling Plan contained in Appendix I of this document.
   

1. 
   Inspection Level I (see sub-section 5.2 (a))
   

Lot Size (N) = 1200 x 12 or 14,400 units

Container Size = 2.5 lb

Inspection Level = I (see Sampling Plan 1, Appendix I)

Sample size (n) = 13

Acceptance Number (c) = 2

In this example if there are no more than two (2) “defectives” in a sample size of 13 containers the lot is considered acceptable. If, however, there are three (3) or more “defectives” in the sample the lot is considered as failing to meet the requirements. A “defective” as used in the Sampling Plans is defined in the Codex Standard.
b. Inspection Level II (see sub-section 5.2 (a))

If in the foregoing example (5.3 (a)) the quality of the goods is in dispute and a referee method is required for the examination or re-examination of the lot, an increased sample size is taken at Inspection Level II, selecting at least 21 containers.

Lot Size (N) = 1200 x 12 or 14,400 units

Inspection level = II (see Sampling Plan 2, Appendix I)

Sample Size (n) = 21

Acceptance Number (c) = 3

It is not necessary to restrict the sample size to the minimum corresponding to the appropriate lot size and Inspection Level. In all cases a larger sample may be drawn. In the example at 5.3 (b) an even more reliable estimate of lot quality could be made by taking a sample of 29 or even 48 and applying the corresponding acceptance numbers of 4 and 6 respectively.