All the set procedures must be followed for the benefit of everybody working in or visiting the laboratory, including staff from the secretary's office, janitors, cleaning staff and students.
Smoking, eating and drinking is totally prohibited in the laboratory.
All the products used in the laboratory are potentially poisonous if inhaled, ingested or in contact with the skin. If the toxicity of a product is unknown it must be treated as if it were poisonous.
Inhaling aldehydes and osmium tetroxide is dangerous. Toxic substances supplied in the form of fine dust must be handled with care when they are weighed.
Avoid contact with toxic substances that can be absorbed by the skin. Eyes must be suitably protected and hands must be washed frequently. It is mandatory to wear a lab coat in the laboratory.
In the event of spillage you must use the products at your disposal in the laboratory and ask the technicians of the service for help.
Spillages of a fixer, aldehyde or osmium tetroxide must be covered with powdered milk. Reduce evaporation and the inactive.
The danger posed by these fixers depends on their volatility and TLV (Threshold limit value). TLV refers to the concentration of the substance in the air. Indicate the conditions to which it is considered that almost all the workers can be exposed daily without any harmful effects. For the fixers, the TLV must be considered as the maximum atmospheric concentration to work safely. As a guideline, if you can smell the fixer faintly it is near the TLV, and if the smell is clearly perceivable the TLV has probably been exceeded.
Solutions of formaldehyde and glutaraldehid must be prepared in a gas bell. You can also do this in a well-ventilated laboratory to avoid exceeding the TLV. Solutions of acrolein and osmium tetroxide have a higher steam pressure and can only be manipulated under an effective gas bell.
1. Mercury, cadmium, lead and uranium are poisons with cumulative effects. They can produce chronic poisoning if the laboratory or personal hygiene are inappropriate.
2. Chromic acid and chromates can produce burns and ulcers, and can provoke skin tumours.
3. Picric acid and metal picrates can explode if they are dry.
4. Cacodylate tampon contains arsenic and this can be absorbed by the skin or inhaled if it is
pulverised. Volatile compounds can be produced if it reacts with reducing agents.
1. Fixer solutions must be mixed and dispensed on a flat tray with absorbent material underneath.
2. Receptacles reinforced with a threaded lid must be used.
3. Fixers must be handled in the same way as other harmful chemical products.
4. A deep tray or a hermetic container must be used to transport bottles of fixers around the laboratory.
5. Gloves must be used whenever there is a risk of the fixer coming into contact with the hands.
6. Hands must be washed regularly with soap and cold water.
7. Glasses must be worn if there is a danger of splashing.
8. Protective glasses or a mask must always be worn when using osmium acroleina or fixers that contain osmium. Normal security glasses do not afford enough protection.
Storage of fixers
1. Do not store large amounts of fixers, only the amount required for your usual work. Moreover, the fact that glutaraldehid polymerises with time and goes from being a monomer to being a polymer, with reduced power as a fixer, must be taken into account.
2. It is advisable to use small, strong, one-litre bottles; domestic receptacles must never be used.
3. All bottles must be clearly labelled with a detailed list of the contents and the dangers they pose (if they are known).
4. The outside of all receptacles must be kept clean.
Take precautions when neutralising osmium tetroxide
The best way to neutralise osmium tetroxide is with vegetable oil. Spillages must be cleaned up with powdered milk as this is very absorptive, but it does have the inconvenience that it cannot be stored for a long time since it rots and smells bad, which does not happen with vegetable oil. Oil has the advantage of floating on water that contains osmium and, therefore, it retains vapour better.
To neutralise an osmium tetroxide solution to 2%, you must use double the vegetable oil than the volume of the solution you want to neutralise. Thus, if you have to neutralise 10 ml of osmium tetroxide you will need 20 ml of vegetable oil. If you increase the concentration or the volume, you must increased the oil proportionally.
Once you add the oil you must wait for it to turn black.
To confirm that you have all the osmium tetroxide reduced and you have added the correct volume of vegetable oil, you can cover the jar with a slide or a filter paper soaked with oil. If it turns black it means that it is not yet completely neutralised and more oil is needed.
Afterwards, the recipient must be stored until the company in charge of eliminating it picks it up. As a special product, it belongs in group 7.
Elimination of waste
The University of Girona has a selective waste collection programme through the company Chemical Tecnología y Medio Ambiente, S.A. This company manages the collection and subsequent elimination or recycling of waste.
Waste must be collected in accordance with these designated groups:
Group 1: chlorates
Group 2: non-chlorates
Group 3: aqueous solutions
Group 4: acids
Group 5: oils
Group 6: solids
Group 7: special waste
Groups 1, 2, 3, 4 and 5 are only used for liquid waste.
Group 6 is only used for solid waste.
Group 7 can be used for both liquid and solid waste.
The company supplies the receptacles required for the selective waste collection, but wherever possible the product's original receptacle and packaging must be used to store it in.
In all cases, the receptacles must be labelled with University of Girona labels, indicting the following:
- Generic group to which the waste belongs
- Majority component
- Identification of the product
- Recommendations about the risk it poses and safety measures that must be taken into account
- Date the recipient started to be used and date it finished being filled up
- Name of the UdG centre that generated the waste
Once the container is full the service technicians must be informed to start another container and store the full container until it is picked up.