You will need to know the volume of oxygen in your container so that you can
determine what size of oxygen absorber to use.

Oxygen is measured in cubic centimeters (cc). The sizes of our oxygen
absorbers correspond to the amount of oxygen they absorb. For example, a 300 cc
oxygen absorber will absorb 300 cc of oxygen.

The table below indicates how many cc's of oxygen are
contained in the more common sizes of food storage containers.

Volume in Empty Container |

#10 can |
3,980 cc |

5 gallon plastic pail |
18,942 cc |

6 gallon plastic pail |
22,730.4 cc |

Oxygen
absorbers are rated by their capacity to absorb oxygen as measured in cubic
centimeters (cc).

There are two key elements to keep in mind when determining what size of
oxygen absorber to use:

## Headspace

As in the table above, a #10 can has a volume of 3,980 cc. If you fill this
can to 90% of its volume, you will have 398 cubic centimeters of headspace.

Because air is 20.5% oxygen, this headspace will contain 81.6 cubic
centimeters of oxygen (0.205 x 398 = 81.6).

## Voidspace

If a five-gallon bucket were filled with children's marbles, the spaces in
between the marbles (void spaces and head space) would represent 38% of the
volume of the five-gallon pail ( 0.38 x 18,942 cc = 7,197.96 cc residual air
volume ). Of this number, 20.5% is oxygen.

(x) cc Headspace + (x) cc Voidspace = Residual Air Volume

In order to determine how much oxygen absorbing capacity you require, we must
determine the residual air volume. Here is a fairly simple way of determining
this quantity, using weight and volume measurements.

1. Determine the volume of your container. Use the table above for common
container types.

Or,

a. use this
formula if you do not know the volume and your container is a regular shape.

b. use this
formula if you do not know the volume and your container is an irregular
shape.

2. Weigh the food product and convert this weight to grams. (See
conversion
table below.) To be completely accurate, make sure you subtract the weight
of the container to get the net weight of the food.

3. Subtract the cubic centimeter volume found in Step 1 above from the gram
weight found in Step 2 above to determine the headspace and voidspace, or
residual air volume. (This will be a measurement in cubic centimeters)

4. Finally, as there is approximately 20.5% oxygen in air, multiply the
residual air volume found in Step 3 above by .205 to get the cubic centimeter
volume of oxygen in your product container.

### Example:

We want to know what size oxygen absorber to use for a 5 gallon bucket of
rice.

1. We determine from the table above that there are 18,942 cubic centimeters
in a 5 gallon plastic bucket.

2. The rice weighs 35 pounds which converts to 15,876 grams.

3. 18,942 (cc) container volume - 15,876 (g) rice = 3,066 cc residual air
volume.

4. 3,066 (cc) residual air volume x .205 (oxygen fraction in air) = 628.53 cc
oxygen volume

5. Since the size of
oxygen absorbers are rated and named according to the amount of oxygen they
absorb, we know that a 750 cc
oxygen absorber will be sufficient for this bucket of rice

If your container is a regular shape such as in the diagram below, use the
formula which follows:

### NOTE: one milliliter (ml) = one cubic centimeter (cc)

If your container is an irregular shape, such as a flexible mylar® bag, the
oxygen volume can be determined by doing the following:

For purpose of this calculation, we are going to assume that the
specific gravity
of the product has a value of 1.

1. Fill a vessel with water. Place your product container (containing the
food) into the vessel and let the water overflow.

2. Remove your container from the vessel.

3. Measure how much water it takes to fill the vessel back up with water. The
water is measured in milliliters (ml). There are 29.57 ml in one fluid ounce.

4. Measure the weight of the product container in grams (g). There are 28.35
grams in an ounce.

The formula for this is as follows:

### NOTE: one milliliter (ml) = one cubic centimeter (cc)

oxygen absorber
will be more than sufficient.
## Specific Gravity

Relative density (measure of the density of a substance compared with that of
a standard) when the standard substance is pure water.

MEASUREMENT
CONVERSION TABLE |

Multiply by: |

inches |
centimeters |
2.54 |

square inches |
square centimeters |
6.54 |

cubic inches |
cubic centimeters |
16.387 |

fluid ounces |
milliliters |
29.57 |

ounces (weight) |
grams |
28.35 |