Paraquat is toxic if swallowed and the concentrated formulations are irritants to eyes and skin. There have been highly publicized reports of fatalities related to the ingestion of paraquat.
When paraquat was first introduced in the 1960s, a common malpractice was to decant pesticides into smaller containers such as drink bottles without appropriate labeling. The original paraquat formulations were odorless reddish-brown liquids which, as a result of illegal decanting, could lead them to be mistaken for drinks such as cola, tea, or red wine. Regrettably a series of fatal poisonings due to accidental ingestion occurred.
Steps were introduced in the late 1970s and early 1980s to further address this:
- Pack sizes were changed to discourage the practice of decanting
- A new global labeling standard was introduced
- Stewardship and training efforts were enhanced to ensure that people handling paraquat were aware that it contains chemicals and should be used exclusively for the control of weeds. These were directed, in particular, towards smallholder farmers in developing countries where the majority of incidents occurred
- Paraquat formulations were given three 'safening' agents to reduce the incidence and severity of accidental ingestion:
- blue dye
- alerting agent (a strong and deterring odor)
- emetic (to induce vomiting).
The combination of these measures has helped address the problem of accidental ingestion.
Unfortunately, there are incidences reported of deliberate exposure to paraquat by people intent on committing suicide. While crop protection products are one of the methods used to commit suicide, they are not the most frequent.
Paraquat is irritating and harmful to eyes and skin, especially in its concentrated form, so gloves and eye protection should be worn (as with all pesticides when mixing concentrates). Prolonged and repeated contact of spray-strength paraquat with skin, through leaking spray equipment or poor personal hygiene, can cause skin irritation and even damage in severe cases. Similar poor practices have been reported to be associated with nail damage and nose bleeds. If the basic label precautions are followed, these symptoms will clear quickly with no lasting effect. The skin irritation and related symptoms heal when exposure to paraquat ceases and the affected areas are washed or treated as needed. To put this into context, one would not leave skin in prolonged contact with oven cleaner, degreaser, oil, petrol, solvents, dishwasher fluid or many other common substances without experiencing skin damage and effects on health.
Enhancing human safety through product stewardship and education
Some companies, such as Syngenta, which manufacture paraquat have initiated stewardship and education programs for customers around the world in order to train farmers on the safe and appropriate use of paraquat. The results of these educational efforts demonstrate that basic education can significantly increase safe practices among farmers.