In 1892, Grinnell organized the General Fire Extinguisher Co. in Providence, R.I., an amalgamation of several smaller companies, which became the foremost organization in its field of manufacture. Grinnell died in 1905 in his hometown of New Bedford. In 1919, General Fire Extinguisher Co. was renamed Grinnell Co. In 1969, Grinnell Co. was purchased by ITT (International Telephone & Telegraph) and became ITT Grinnell. A few years later, ITT Grinnell sold its US industrial activities to Tyco International. Grinnell remains today a trade mark inside the Tyco group. In 2001, Grinnell Fire Protection was merged with the Simplex Time Recorder Company to form SimplexGrinnell, which is the largest fire protection company in the world. ITT Grinnell supporting products are still sold today by Anvil International in the US and PSS in Germany.
Grinnell was a director of several banks and manufacturing companies. He was inducted into the Rhode Island Heritage Hall of Fame in 1984.