The low-down: True.
It all comes down to what kinds of ingredients you pack in your salad, but spoiler alert: They're all most likely perishable and should be refrigerated ASAP. Lettuce, dairy-based dressings, cheeses, and other produce in your salad, to name a few, should be stored properly at a temperature at 40°F or below. And most protein, such as meat, poultry, eggs, and seafood, should also be refrigerated within two hours of cooking or purchasing, or within one hour if the temperature outside is above 90°F, says Cassell.
So basically, unless you're planning on a 10 a.m. lunch, you should store your salad in an insulated lunch bag with an ice pack, or just stick your Tupperware in the office fridge.