Self-Indicating Silica Gels : New Regulations.

GeeJay Chemicals Ltd.
UK SUPPLIER OF DESICCANT SILICA GEL
FOR PREVENTING MOISTURE DAMAGE.

Self-indicating silica gels will adsorb moisture in exactly the same way as
standard non-indicating (white) silica gel, but they will literally indicate when
they are becoming saturated by changing their colour.
This is useful in two ways. Firstly, a silica gel sachet or breather unit where the
gel has changed colour, gives an immediate warning that it should be
replaced. Secondly, if regenerating the silica gel, the self-indicating grade will
be ready for reuse, when its original colour has returned.

Until recently the only indicating silica gels used a small concentration (between
0.5 and 1.0% weight for weight) of moisture sensitive cobalt chloride indicator,
which gives a blue silica gel. This changes to pink as it adsorbs moisture and
becomes saturated, returning to blue as it is regenerated.

There are now alternatives to this traditional self-indicating
silica gel though, following European Commission Directive 98/98/EC
(amendment to 67/548/EEC) reclassifying cobalt chloride as a potential
carcinogen by inhalation. Subsequently, the latest British Chemicals (Hazard
Information and Packaging for Supply) Regulations CHIP 99(2) now include
cobalt chloride in the Approved Supply List (Fifth Edition) for the first time.

This regulation came into effect on 1st July 2000, resulting in a number of changes.

We are now labelling all containers of self-indicating (blue) silica gel according
to the new regulations. This will include a TOXIC symbol and the risk phrase
'May cause cancer by inhalation'. We have produced a new Material Safety
Data Sheet to reflect these changes (reproduced below).

Users are advised to 'avoid raising dust' and to use 'a suitable, effective dust mask'
when handling the material. Being classified as a hazardous material, it will
also be classed as a special waste and need to be disposed of accordingly.

Please note the following points :

(1) Self-indicating (blue) silica gel is the same as it has been for 60 years - there has been no change
in its formulation or composition.
(2) Self-indicating (blue) silica gel has not been banned from use.
(3) The new regulations apply to cobalt chloride not silica gel, so they do not apply to non-indicating (white) silica gel.
(4) Self-indicating (blue) silica gel is still classified as non-hazardous for transportation.
(5) As far as we are aware, these regulations apply only to European Community countries.
(6) Some companies have carried out Risk Analysis on using the self-indicating
(blue) silica gel and are continuing to use it with certain safeguards in place.
(7) Self-indicating (blue) silica gel in beaded form or in sachets gives
virtually no exposure to dust.

NEW INDICATING SILICA GELS.

Many new self-indicating silica gels with non-toxic indicators are now available.
We have regular stocks of the following :

Orange to Green self-indicating.
This is in a 2 - 5 mm beaded form, suitable for dynamic adsorption processes and
general use. Beaded silica gels are less dusty than their granular counterparts.
It is also in stock in a fine granular form, suitable for packing into small sachets
and for use in drying flowers.
An organic indicator gives a colour change from orange (active) to dark green (near exhausted),
probably the strongest colour change of all the new gels.

Orange to Colourless granular self-indicating.
These are the strictest parallel alternatives to traditional blue to pink silica gels,
offering the same adsorption characteristics, whilst being available in fine,
medium and coarse grades for different applications. They use iron compounds as
their indicators, changing from a deep orange to colourless as they adsorb moisture.
They are the best suited new gel to repeated regeneration and reuse.

All new self-indicating silica gels are sold loose in bulk packs or packed in sachets.
Blue to pink self-indicating is, of course, still available.

MATERIAL SAFETY DATA SHEET.

Product and Company Identification.
SELF-INDICATING (BLUE) SILICA GEL.
Geejay Chemicals Ltd., 16 Gosforth Close, Sandy, Beds., SG19 1RB.
Telephone : 01767 682774.

Composition/Information On Ingredients.
Synthetic amorphous silica impregnated with cobalt chloride.
Formula SiO₂with CoCl₂
Silica Gel - CAS No. : 7631-86-9 EINECS : 231-545-4
Cobalt Chloride – CAS No. : 7646-79-9 EINECS : 231-589-4

Hazardous components : Cobalt Chloride < 1%
Classification symbol T Carc. Cat. 2
Risk Phrases R49 May cause cancer by inhalation

Hazards Identification.
The product is very adsorbent and may have a drying effect on skin and eyes. Sensitisation of skin and respiratory system is possible. Any dust could be a nuisance. Evolves heat on contact with water.
Cobalt Chloride has been classified by IARC (International Agency for Research on Cancer) in Group 2B. Possibly carcinogenic to humans. Very toxic to aquatic organisms. May cause long term adverse effects in the environment.

First Aid Measures.
1. After inhalation: remove to fresh air.
2. After skin contact: wash with water, if skin irritation persists seek medical advice.
3. After eye contact: flush with water, if irritation persists seek medical advice.
4. After ingestion: give water to drink, seek medical advice.

Fire Fighting Measures.
1. Products of combustion: not combustible.
2. Fire fighting procedures/extinguishing media : not applicable, unused material will not burn. Use media appropriate for surrounding fire.

Accidental Release Measures.
1. Personal precautions: respiratory protection if dusty, eye and hand protection.
2. Environmental precautions: try to prevent material from entering drains or watercourses. Advise authorities if spillage has entered watercourse or sewer.
3. Methods for cleaning up: sweep up or preferably vacuum up and collect in suitable container for recovery or disposal. Avoid raising dust.

Handling and Storage.
1. Precautions during handling: avoid raising dust, vacuum up dust sources, prevent static electric sparks. Beads may be slippery.
2. Precautions during storage: store in sealed containers in a dry place.

Exposure Controls/Personal Protection.
1. General
Respiratory: effective dust mask.
Hand: protective gloves.
Eye: goggles, safety glasses.
Skin: overalls

2. Exposure limits.
Amorphous silica
UK EH40:OES 8 hr. TWA 6mg/m³ total inhalable dust
UK EH40:OES 8 hr. TWA 2.4mg/m³ respirable dust.
Cobalt compounds as Co
UK EH40:MEL 8 hr. TWA 0.1 mg/m³
ACGIH:TLV 8 hr. TWA 0.02 mg/m³

Physical and Chemical Properties.
Appearance – blue granules or beads that turn pink on adsorption of water.
Odour – none.
pH – 3.5 minimum as a suspension 100g/l water.
Boiling point/melting point – not applicable.
Flammability/flash point – not applicable.
Density – 700 – 750 kg/m³Solubility – insoluble in water and solvents.

. Stability and Reactivity.
Stability – stable.
Conditions/materials to avoid – evolves heat in contact with water.

. Toxicological Information.
Acute toxicity
Silica, amorphous – oral, LD50>15,000 mg/kg, rat.
- dermal LD50>5,000 mg/kg, rabbit.
Cobalt chloride - oral, LD50>80 mg/kg, rat.

Effects of exposure:
Eyes – dust may cause irritation.
Skin – heat may be evolved when in contact with water. May have a drying effect.
Skin sensitisation – cobalt compounds are skin sensitisers.
Carcinogenicity – amorphous silica is not classified as carcinogenic to humans. There is limited evidence of cobalt chloride in experimental animals.

. Ecological/Biological Information.
Amorphous silica is chemically and biologically inert. It is not degradable. By its insolubility in water there is a separation at every filtration and sedimentation process. Cobalt is a List II substance in EEC Directive 76/464 for the control of dangerous substances in the aquatic environment. This product must not be allowed to contaminate soil and water.

. Disposal Considerations.
Disposal according to national and local regulations.
This material is classified as special waste under the UK Special Waste regulations 1996.
This material is classified as a hazardous waste under EEC Directive 91/689.
Used product may have different hazards or properties from the original product. This MSDS does NOT therefore apply to spent/used products.

. Transport Information.
Not dangerous goods according to the transport regulations of UK Road, RID-ADR, IMO, MARPOL and ICAO.
Not classified as dangerous goods under the United Nations Transport Regulations.
No special packaging requirements.

. Regulatory Information.
As required by the Chemicals (Hazard Information and Packaging for Supply) (Amendment) (No. 2) Regulations (CHIP 99(2)) and in Approved Supply List 5^th Edition.

This material contains less than 1% cobalt chloride.
EC Classification Carc. Cat. 2.
Labelling information
Symbol Toxic T
Risk Phrases R49 May cause cancer by inhalation
Safety phrases S22 Do not breathe dust
S45 In case of accident or if you feel unwell, seek medical advice (show label where possible)
S60 This material must be disposed of as hazardous waste
S2 Keep out of reach of children

. Other Information.
As with any material, general industrial hygiene and housekeeping standards should be observed.

This information is given in good faith and is based on information supplied by manufacturers of the material indicated. The suitability of the product for any particular use is not suggested or implied. The data does not constitute a specification and any properties shown are not guaranteed.

This latest edition (July 2000) of the Material Safety Data Sheet of SELF-INDICATING (BLUE) SILICA GEL contains a number of major changes. This is due to the reclassifying of Cobalt Chloride as a hazardous material. These changes have effected Sections 2, 3, 8, 11 and 15.

Date 31/01/2005.

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