Inclusion Criteria:  Have a Type 1 Diabetes diagnosis for at least 6 months Have been receiving insulin therapy via multiple daily injections or using an insulin pump and have been stable for at least 3 months prior to screening Have a HbA1c level of ≤ 9.0% at screening Have sufficient venous access for collection of blood samples Have good general health, apart from their Type 1 diabetes, with no prior history of choanal atresia, nasal/pharyngeal blockage or nasal anomaly  Exclusion Criteria:  Have a presence or history of glucagon hypersensitivity Have a history of pheochromocytoma Have a history of epilepsy or seizure disorder Have 1 or more congenital anomalies to the anatomy of the nose, or require changes to the anatomy of the nose Are using closed-loop insulin therapy, unless such a device is set to 'open loop/manual' mode on the day of the dosing visit Have an episode of severe hypoglycemia or have had glucagon administered , during the 3 months prior to the screening visit and no severe hypoglycemia between the screening and dosing visit