Launching a machine, this gesture is so automatic that we no longer even ask the question of dosage. Pour in the detergent as you wish, close the container, press the button. And yet, this is precisely where a large part of the effectiveness of washing comes into play.
According to ADEME, the Environment and Energy Management Agency, the reflex which consists of overdosing on detergent to “be sure that it washes well” produces exactly the opposite effect to that sought. The agency is categorical: using more detergent does not clean the laundry better. On the contrary, this overdose gradually clogs the washing machine, which ultimately generates bad odors in the appliance itself, odors which end up "contaminating" the laundry washed there. And the impact does not stop at the machine: by overdosing, we also emit more pollutants in wastewater, but also in the air inside the home.
This last point deserves attention, because it is often ignored. We generally associate laundry-related pollution only with wastewater and sewage treatment plants, forgetting that laundry residue also emits compounds into the air we breathe at home. ADEME even goes so far as to recommend, to limit these emissions, favoring powder detergents rather than liquid detergents, the former releasing fewer volatile organic compounds into the air in the home. A detail that is generally completely missed when you choose your product on the shelf, guided more by smell or habit than by this type of consideration.

What this task actually involves

Starting the machine consists of loading the drum with the sorted laundry, dosing the detergent according to the manufacturer's recommendations, selecting the program adapted to the material and the degree of soiling, then starting the cycle. Allow approximately 5 minutes for this entire step, excluding the duration of the cycle itself which generally lasts between 1 hour and 2 hours depending on the program chosen.

Tips and tricks for dosing your laundry correctly

The basic rule remains to scrupulously follow the instructions on the product packaging, which take into account the hardness of the water in your region: the harder the water (rich in calcium and magnesium), the more you must slightly increase the dose to compensate for the loss of effectiveness of the detergent. Conversely, soft water makes it possible to reduce the quantity used without loss of efficiency.
Systematically adapting the dose to the actual degree of soiling of the laundry avoids the reflex of "a little more just in case": clothing worn for a day without visible stain does not require the same dose as a stained kitchen towel or particularly dirty sports clothes. Likewise, loading the machine to full capacity rather than half allows real savings in water and energy, provided that you still leave a little space for the laundry to circulate freely in the drum.
To avoid bad odors that set in over time, avoiding highly scented fabric softeners remains a good reflex: according to ADEME, the more odorous a product is, the more pollutants it tends to emit into the air inside the home, which goes against the desired "fresh linen" effect.

The act of throwing in a load of laundry seems absolutely banal, and it is precisely for this reason that we easily neglect the dosage. However, according to ADEME, this small detail determines both the actual cleanliness of the laundry, the longevity of the machine, and the quality of the air we breathe at home. Enough to reconsider this almost reflex gesture the next time the detergent cap finds itself in your hands.