Cleanroom Safety Introduction


Welcome to the Clean Room facility at LCN. We hope the Clean Room, the Back End laboratory (BEL), and associated facilities will fulfill your needs. Whilst using these facilities, your safety is of paramount importance to us. This document will help make you aware of the rules  and your own role in creating a safe environment.

Safety within the LCN is governed by law, namely the Health and Safety at Work Act. If you have a query regarding safety in the clean room please contact Steve Etienne the cleanroom manager, or the Department Safety Officer, who will deal with it or contact the UCL Safety Officer for a definitive ruling if necessary. The Health and Safety at Work Act places on all of us - the  technical team and each user - the responsibility for awareness of hazards and for behaving in a safe and responsible manner.

Clean Room Facts
The Clean Room is different to ordinary laboratory areas because it has a recirculating air supply which maintains it at a positive pressure of 5 Pa and at a constant temperature of 20-22oC with air humidity at 45 to 50%. The Clean Room is designed as a building within a building. This is to isolate the users from activities in other areas.

Access to Clean Room
Before anyone is allowed to carry out any standard processing in the clean room the risk assessment for the procedure must be studied and signed up to.   Each risk assessment contains details of the appropriate Chemical safety data sheets, and they are available for viewing in the cleanroom office. New procedures will require a new risk assessment, these are the the responsibility of the User's Principal Investigator and must be counter signed by the Department Safety Officer.

Access to the equipment requires payment and prebooking 24 hours in advance.  The procedure is outlined  here.

Working Hours

A document describing summarising Working Hours rules can be downloaded.

Days Time Period Notes
Monday to Friday 09:00 - 18:00 Normal Hours Normal Access applies
Monday to Friday 18:00 - 23:00 Out of Hours Follow Out of Hours guidance
Saturday, Sunday 09:00 - 23:00 Out of Hours Follow Out of Hours guidance
Every Day 23:00 - 09:00 Overnight No Access, Automatic Processes only
Christmas & Easter break 24 Hours Closed No Access, Equipment Shut down

Out of Hours Periods

  •  All activities must conform to LCN’s Safety Guidance Notes GN3 on Lone working, published as part of the Health & Safety Policy.
  • An Out of Hours Document defines who is permitted to work, and restrictions on operations that can be carried out.  This document will be posted in the Changing room  and will be updated from time to time.
  • All equipment must be pre booked using the Web booking system
  •  There must always be minimum of two named people in the Cleanroom
  • Each person must be aware of the work that the other is doing, and to be working close enough to be of assistance in an accident or emergency.
  • Cleanroom staff must authorise in advance who is working, what is being done and when it will occur.  This information must be noted in the Diary kept in the cleanroom entrance.
  • Only certain operations are permitted and some are prohibited, as defined on the document.
  •  Operations not on the list may be considered after additional precautions in the form of a Risk Assessment are carried out.

Overnight Periods

  •  No persons may access or remain in the Cleanroom
  • Only operations designated as automatic operations on the Out of Hours Document can carry on during this period.
  • During this time the LCN building is locked.

Closed Periods
UCL has a shutdown during Christmas and Easter holidays, and maintenance of equipment may also require Cleanroom shutdowns. No access is permitted except for maintenance staff during these periods, and equipment will be turned off.  Dates will be notified in advance.

Clean Room Telephne Numbers
Cleanroom Manager: 39904
Department Safety Officer: 30574
Technical Team: 33514 30572
Cleanroom:  39990, 39991 or 39994
Back End Lab: 39982

Equipment and chemical log books

All significant equipment has a log book which must be filled out in full. The logbooks are located on the cleanroom computers, and in paper form near to the equipment.

CCTV  has been installed in the Clean Room and it is networked to the Clean Room office. This provides a check of who is in the facilitiy at all times.  This is essential in the event of a fire or other emergency. The images are recorded and can be retrieved if required.

As people start to use the equipment they will be trained by the Cleanroom staff.  A training record will be maintained listing a person’s competency for an item of equipment.  This competence will graded as either User or Expert. 
A User may use the equipment, within the guidelines given in the Cleanroom Operating Instructions for the equipment. 
An Expert will additionally be able to reconfigure the equipment, and train people to be Users.
People will be addedd to the permitted people list for out of hours working at the discretion of the Cleanroom Manager

Undergraduates & Supervision

MSC students and undergraduates are not permitted to use the Clean Room alone. LCN Guidance Note GN4 details the requirements for supervison. Any Undergraduate or MSc project work work must be supervised, or carried out by the Clean Room staff.  These students will NOT be permitted in the Cleanroom outside normal hours.

Basic Safety rules
The general rule for your safety in the Clean Room should be that in the event of an incident, GET OUT of the room immediately and then call for help. It is not necessary to remove cleanroom clothing before leaving in an emergency, although removal of the overboots will enable a safer descent of the staircase. If you feel ill or faint or have your vision impaired ask for assistance immediately. In case of emergency dial 222 from any phone. In the remainder of this document RULES are written in BOLD CAPITALS.

Fire & Safety appliances

There  are fire extinguishers and fire blankets in this facility, but these should be used by trained people only. In the event of a fire GET OUT and GET HELP. Your safety comes first. There are FIRE ALARMS  in the cleanroom,  if they sound LEAVE THE FACILITY IMMEDIATELY, EXIT THE BUILDING and ASSEMBLE at the fire assembly point at the entrance to the Bloomsbury Theatre on Gordon Street.

In the Clean Room lobby there is an emergency spills kit for use by the Cleanroom staff. In case of spill, evacuate the area and REPORT ALL SPILLS to them.  Do not attempt to clean them up yourself.

A Safety shower and eyewash bath is provided for emergency flushing of chemical spills.

Clean Room clothing

All people entering the cleanroom must wear a set of Clean Room clothes. The garments are changed and cleaned every week. These garments do not provide any Chemical or Mechanical protection. If you tear, rip or spill acid on the garments REPORT DAMAGE to Cleanroom staff. They will issue a new set and remove contaminated garment from use.

Air conditioning
The air conditioning is controlled externally to the room. If the system fails, loss of pressure to the room occurs and the noise level of the room drops - this is a form of audible warning. The laminar flow benches are controlled internally by switches located on the benches, as are the bench lights. If the fans in these overheat and cause a fire switch them off and GET HELP.

Electrical appliances
The Clean Rooms uses normal 240V AC 3 pin plugs and sockets. All high voltage sources are securely boxed. Emergency power Off buttons are located in every tunnel, these will cut the electricity supply to everything in the vicinity, eexcept the lights and ventilstion fans.  Only Cleanroom staff are permitted to wire electrical plugs or open such electrical enclosures.

Vacuum systems

The main hazard is the risk of implosion of the evaporator glass bell jar. Always cover the bell jar with its protective shield. REPORT ANY CRACKED OR CHIPPED BELLJARS to Cleanroom staff. Vacuum chambers and pumps exhaust to ducting outside of the room. The reactive ion etch and deposition plasma-tools have safety interlocks to prevent release of gases to the atmosphere or RF power generation when the chamber is open.

Handling of chemicals and their misuse is the major cause for concern in the cleanroom. This is especially so given that some users may little knowledge of basic chemistry. EYE PROTECTION IS PROVIDED AND MUST BE WORN WHEN HANDLING CHEMICALS. The number of chemicals available in the Clean Room is limited to the minimum necessary.

If you want to bring specialist chemicals into the room for your research a risk assessment is required to identify any hazards that your chemicals may present for you and others befere permission will be granted.

The quantities of chemicals used should be minimal, acording to the size of the substrate and container. DO NOT LEAVE CHEMICALS STANDING UNATTENDED or IN WET BENCHES AFTER YOU HAVE FINISHED. If you make mixtures to keep, these must be in a suitable container, labelled with your Name, Contact number, Contents, date and have appropriate risk signs on it.  These must be stored in the Underbench cupboards.  Chemicals must be disposed off in the correct manner. If you have spilt acids or alkalis on the wet bench top, wash the top down and dry with a cleanroom paper towel before leaving the room. Chemical processes must only be carried out in the the appropriate wet stations which have inert surfaces and a fume extraction system. If the extract system fails the room pressurisation will give a partial protection via the extract ducts.

Acids & Alkalis

In the event of spillage of acids or alkalis on yourself ALWAYS FLUSH WITH COPIOUS QUANTITIES OF WATER over the contaminated area. Flushing should be for at least 2 to 3 minutes and carried out immediately the spillage has occurred. An emergency eye wash station is provided to flush the eyes.
Acids commonly used in the Clean Room are hydrochloric, nitric and sulphuric acids. Sulphuric acid represents a high risk due to the exothermic reaction with water causes rapid heating and the mixture can explode. NEVER ADD WATER TO ACID, ALWAYS ADD ACID TO WATER SLOWLY so that the heat of dilution is released in a controlled manner. This warning especially applies to making up Hydrogen Peroxide-sulphuric acid mixture, ADD ACID SLOWLY TO HYDROGEN PEROXIDE.

Within LCN, HF acid is only to be used in the dedicated wet bench in the cleanroom. ONLY those people who have completed the HF acid induction are allowed to use HF acid. HF ACID MUST BE USED IN A PTFE CONTAINER. YOU MUST USE HEAVY DUTY GLOVES AND ALWAYS USE EYE PROTECTION. If it is spilt onto your skin you will not feel any immediate reaction. It is absorbed and attacks bone tissue under the skin with excruciatingly painful erosion. Hydrofluoric acid is extremely water soluble and can be flushed off easily. Use calcium gluconate gel after flushing with copious amounts of water. Medical treatment must be sought IMMEDIATELY after such an incident. By each tube of calcium gluconate gel there is a document containing the information required by hospital personnel. THIS MUST BE TAKEN WITH YOU WHEN SEEKING TREATMENT. Copies can be obtained from the Clean Room office. A healthy fear and respect for this acid will ensure safe usage.

Solvents constitute a real fire hazard. They are extremely inflammable and can ignite if heated, and must never come in contact with acids.  Acetone, methanol and isopropyl alcohol (propanol-2-ol) should only be heated with extreme caution and under CONSTANT SUPERVISION. Solvents can be heated in small quantities in the wet bench by using a temperature controlled water bath set to a temperature below the ignition point to minimise the risk of ignition of the vapour. This operation represents one of our most potentially hazardous processes. A cover should always be at hand to smother the beaker in the event of ignition. All Solvents are stored in a fireproof cabinet under the bench. Waste solvents are disposed of by pouring into the waste container provided in the wet station.

Do not dispose of acid or alkali mixtures into the solvent waste bottles/bins. Large quantities of noxious fumes can result as well as possible explosive reactions. Locate the correct waste bin and use properly for HF acid, solvents, semiconductor waste, glass and domestic waste. All non domestic waste is stored in a metal cabinet  until removed to the central waste store.

A number of hazardous gases are in use in the cleanroom and certain items of equipment.  The installation has been carefully designed for safety of the hazardous gases, and uses only welded pipe work and VCR connections in ventilated enclosures.  Gas detectors are located everywhere, and will initiate an alarm signal and shut down the hazardous gas cylinder if any leak is detected. The gas alarm indicators will be shown to all users.  IF A GAS ALARM SOUNDS THEN LEAVE AREA IMMEDIATELY.

MODIFICATIONS to any gas line are NOT PERMITTED, except by Cleanroom staff or qualified Contractors after a risk assessment is done.  Only certain types of fitting are permitted.  Any new equipment introduced to the cleanroom must be properly installed by qualified people.

Back End Laboratory (room 2.02)
The BEL has equipment for finishing fabricated devices, using processes that are too dirty to be performed in the Cleanroom.  Procedures are in place for mechanical thinning and vacuum equipment cleaning in the fume cupboard, and bonding, sawing, and scribing at the appropriate bench. Standard Operating Procedures of each process are available. They should be followed at all times. Access to equipment in this room is controlled by same system as that of the Cleanroom.  While in this room, YOU MUST WEAR A LAB COAT WHEN WORKING WITH CHEMICALS.