Post: Do Pesticides Expire?Understanding Shelf Life In South Africa

May 3, 2026

Do Pesticides Expire?Understanding Shelf Life In South Africa

A question often raised in the Forestry Sector is whether pesticides “expire” and, if so, what should be done if a product is past the date printed on the label.

The short answer is that pesticides do not suddenly become unusable after a specific date, but their effectiveness and stability can decline over time. This is why manufacturers provide a shelf life specification and storage instructions.

WHAT DOES “SHELF LIFE” MEAN?

Shelf life refers to the period during which a pesticide remains suitable for use when stored in its original unopened container under recommended conditions.

Over time, the active ingredient in a pesticide formulation can degrade, potentially reducing its effectiveness or altering some of the product’s physical or chemical properties. Because of this, pesticide products are given a defined shelf life.

WHY DO MANY PESTICIDES ONLY SHOW A MANUFACTURING DATE?

Many pesticide labels do not display an expiry date but instead indicate a date of manufacture.

In these cases, the regulatory guidance under the Fertiliser, Farm Feeds, Agricultural Remedies and Stock Remedies Act 36 of 1947 generally assumes that pesticides have a minimum shelf life of two years, unless otherwise specified by the manufacturer.

This means that if a pesticide label only shows the manufacturing date, the product can typically be assumed to remain within its shelf life for two years from that date, provided it has been stored correctly and the container remains unopened and intact.

Manufacturers must demonstrate through stability studies that the product remains within specification during this period.

These studies confirm that:

– The active ingredient remains within acceptable limits.
– The formulation remains physically stable.
– The packaging remains suitable and intact.

If manufacturers wish to claim a longer shelf life, they must provide accelerated or real-time stability data demonstrating that the product remains stable beyond two years.

WHAT HAPPENS IF A PESTICIDE IS OLDER THAN ITS SHELF LIFE?

A pesticide that is older than the labelled shelf life is not automatically unusable. However, its suitability should be verified.

Under Act 36 guidance, shelf life can only be extended if testing confirms that the product still meets specifications. This may include testing for:

– Active ingredient concentration
– Physical and chemical properties of the formulation
– Packaging integrity
– Visual condition of the product

Without such verification from the manufacturer or registration holder, the product should not be used once it is past its shelf life.

DISPOSAL OF EXPIRED PESTICIDES

If a pesticide has exceeded its shelf life and cannot be verified as suitable for use, it must be disposed of according to the relevant legislative pesticide disposal procedures and relevant SOPs.

Expired agricultural remedies are considered regulated waste, and incorrect disposal can pose environmental and legal risks. Always follow the appropriate disposal procedures, provided on the LABEL, and approved waste management channels when dealing with expired products.

WHY ORDERING THE CORRECT QUANTITY MATTERS

This is also why it is important to only purchase the quantity of pesticide that will realistically be used within a season. Bulk purchasing can sometimes appear cost-effective, but unused stock may remain in storage long enough to exceed its shelf life. Once this happens, the product may need to be disposed of through approved hazardous waste channels, which can be costly and administratively burdensome. Careful planning and responsible procurement can therefore help reduce both waste and unnecessary disposal costs.

THE KEY TAKEAWAY

Pesticides do not suddenly “expire,” but their quality and effectiveness can deteriorate over time. Shelf life specifications, supported by stability testing, ensure that products remain safe and effective when used within the recommended storage period.

For pesticide users, good practice includes:

– Storing products according to label instructions.
– Keeping pesticides in their original sealed containers.
– Assuming a two-year shelf life from the manufacturing date unless otherwise specified.
– Following proper disposal procedures, as per label instructions, for expired products.
– Purchasing only the quantity that can realistically be used within a season.

Taking these steps helps ensure both regulatory compliance and responsible pesticide stewardship.

Written By: Roger Poole, TIPWG Chemical Liaison Officer

Source: Forestry In Focus