Mr Brownlee said Parliament needed stricter policy and procedures to detect and assess any suspicious matter or materials that arrived.
White powder was also sent to the electorate offices of Peter Dunne, John Banks, and to the French embassy.
It was later found to be baking soda. All the envelopes originated in Waikato.
Mr Dunne said police confiscated a note that had arrived with the powder at his Johnsonville office before he or his secretary could view it.
"I've had no contact from police at all about it. My impression from talking to my staff member ... is that it was dealt with seriously and appropriately but that there are questions about the lines of communication back to Parliament.
Mr Dunne said it raised serious concerns that no one in Parliament knew what needed to be done.
Parliamentary Service spokeswoman Diana Wolken said it had policies and procedures in place for dealing with a range of security incidents, including those involving powder.
"It routinely conducts a debrief after an incident. It is in the process of conducting a debrief of the incident involving Mr Brownlee's office last week,'' she said.
"That debrief will review the service's response to the incident and also consider the validity of its policies and procedures,'' she said.
Today Health Ministry offices in central Wellington were evacuated after an envelope containing white powder was opened. The powder was found to be inert.
Yesterday Greymouth's centre was cordoned off after a man walked in with an envelope containing white powder and a note. The powder was found to be flour.
