Sweat smells on t shirts

[Ric.ror]

I don't know why as he is scrupulously clean
But my sons work t shirts have started to smell
He changes them regularly and I wash them on 40c
I have even started to add a scoop of a stain removing hygiene powder and they still smell
Can anyone offer any advice

[Buenchico]

Are you using a 'biological' washing agent?

[jomifl]

Is your washing machine working properly? try washing one by hand in the same powder and see if it is any better.

[hc4361]

40 degrees isn't hot enough.

[Ric.ror]

Thank you
Yes I am using a bio powder
My washer is working fine
What 0c should I wash at?

[hc4361]

60 if you think the material can take it.

[Anngel123]

Vinegar (white or wine) in the final wash might help

[Ric.ror]

Should I continue to use the hygiene powder?
Thank you for your answers btw

[Ric.ror]

Sorry just seen the vinegar / wine answer
Would I be able to apply the vinegar prewash?
To kill the bacteria

[nungate]

Don't know if this could work, but dissolved aspirin has been known to remove sweat stains from clothing so if you were to give it an overnight soak in a solution of soluble aspirin and then a wash in a biological powder might work.

[EDDIE51]

Are they cotton ? if so wash at 90 deg , 40 is MUCH too low ! 60 deg if not cotton.
Use half the normal amount of wash detergent and a scoop of washing soda. (90p a Kilo at the supermarket ! a kilo does 20 t0 30 washes) Do NOT bother with stain removing powder, it is useless, washing soda is less than 10% of the price and does a better job.

[Ric.ror]

Yes they are cotton
I think they call them Fred perry types with the company logos on
He also has sweatshirts
There isn't any sweat stains just the deodorant stains
Thank you all so much for your answers

[ruthann58]

i add a tablespoon of washing soda

[Ric.ror]

I really want to thank you all so much
This has been an embarrassing problem for him and he really doesn't deserve it
So again thank you so much

[Brinjal]

I just get a bar of washing soap and give a was h under the arms befores tossing them in the machine