Non-dyestuff chemicals: Safe handling in textile finishing
Dyeing and Finishing Information Sheet No 2 - HSE information sheet
Contents
Introduction
This Information Sheet is part of a series. You will need to read it together
with Sheet No 1 Dyes and chemicals in textile finishing: An introduction
which gives background information on hazards, risk assessment and relevant
law.
This guidance was written with the assistance of the Textiles Industry
Advisory Committee (TEXIAC). The aim of TEXIAC is to help protect employees
and others from hazards to their health and safety arising from work activity.
It brings together representatives from employers' associations and
trade unions under the chairmanship of HSE to produce sound, practical advice
to meet the industry's specific needs.
Background
The dyeing and finishing of textiles, even when carried out on a small
scale, can involve the use of a large range of chemical products. Some of
these products will be hazardous to health or safety and you will need to
have made a formal assessment of the risks they present to your employees.
A logical approach to this assessment is to look at each stage of the industrial
process and to consider the potential risks associated with each one.
Outlined below are risks typical to the dyeing and finishing industries
together with risk control measures likely to be appropriate. The list is
not exhaustive and highlights only those risks arising from the toxicological
and chemical properties of the substances in use. Take care to include risks
arising from other sources in your overall risk assessment, particularly
those connected with the manual handling of loads.
Bulk delivery
Risk
Tanks may be either overfilled or filled with the wrong substance.
Precautions
- Label tanks clearly with their contents.
- Draw up a written procedure to cover every stage from the arrival of
the road tanker at the factory gates to its eventual departure. Include
a description of the route to the relevant filling inlet point; identification
of the point and the tank to be filled; the procedure for checking that
ullage space is adequate; together with any appropriate coupling, discharging,
uncoupling, hose draining and cleaning routines.
- Agree the procedure with the supplier so that there is no uncertainty
over 'who does what'. Keep them informed if you make any relevant
changes. One of your employees should be present during a delivery.
Storage
Risk
When mixed, certain chemicals may react in a hazardous way. They may react
violently, generate much heat, or evolve toxic gases.
Precautions
- Make sure you know which chemicals in your inventory are incompatible.
Read the safety data sheet from your supplier. As a rule of thumb, acids
should be kept separate from alkalis and oxidising agents from reducing
agents. However, incompatibilities within the same class of chemical also
exist.1
- Organise your store so that incompatible chemicals are kept in segregated,
marked product bays.
Risk
Fire may arise from ignition of stored flammable substances. The level
of precautions you need to take will depend on the degree of flammability
of the substances in question. Detailed guidance is available.2,3
However, in general terms:
Precautions
- Small quantities of flammable liquids may be stored in the workroom
in a fire-resisting cupboard or bin. Mark the outside to indicate that
it contains flammables.
- Larger quantities of flammable liquids should be stored either in the
open air or in an outside store or in a separate fire-resisting room constructed
in accordance with published guidance.2
- Smoking should be prohibited, particularly in any area where flammables
are stored.
- Provide adequate ventilation at low levels in storage areas to disperse
heavy vapours.
- Ensure that adequate means of escape from the store are maintained.
Risk
An existing fire may be made considerably worse if an oxidising agent is
involved. When heated in a fire, many of these substances decompose with
the liberation of oxygen which can cause an increase in the rate of burning.
Precautions
- Store oxidising agents away from reducing agents and from flammable
and combustible materials.
- Do not exceed the storage time limits, particularly for solid oxidising
agents, since this increases the likelihood of decomposition.
Risk
Some substances, such as sodium hydrosulphite (Hydros), may react violently
if contaminated with a small quantity of water.
Precautions
- Substances which are dangerous when wet should be stored under cover
and off the floor. Container lids should always be kept in place.
Risk
Serious consequences may arise from accidental spillages.
Precautions
- Where liquids are stored in bulk tanks, provide a catchment area, suitably
lined, and capable of containing the total volume of the tank. Any drainage
outlet from a bunded area should be arranged so that it cannot be left
open by accident.
- In product bays where liquids are stored in small containers, provide
sills to hold back spillage. These should be ramped to ensure ease of
transport over them.
- Provide drainage sufficient to cope with regular hosing down and inadvertent
spillage. Remember to take into account possible environmental risks.
- Lay down safe systems of work for coping with major spillages, particularly
of flammables or corrosives.
Dispensing
It is often convenient to locate a number of dispensing points around the
factory to minimise travel distances to machines. However, these should
not be allowed to spring up on an ad hoc basis. Dispensing areas
need to be well laid-out, with plenty of space to work in.
Risk
Splashes of chemicals or very hot water may cause burns.
Precautions
- Consider your overall strategy for dispensing hazardous substances.
If not already in use, consider introducing enclosed chemical handling
systems.
- Do not pour acids and other corrosives straight from small chemical
containers into buckets and jugs. It is difficult to pour in a controlled
way and the liquid is likely to splashback as air tries to replace the
displaced volume in the container. Instead, use proper discharge valves,
powered or hand pumps, ensuring adequate provision for venting. Alternatively
mount the container on a pivoting cradle so that tipping can be controlled.
- Always add acids and corrosives to water, never the other way around.
- Provide appropriate personal protective equipment. This includes gloves,
overalls or aprons, work boots and eye protection, all of which should
be chemical resistant.
- Instruct employees in the proper use of the equipment you provide; give
unambiguous rules as to when it must be used; and then ensure equipment
is used.
- Consider how you would provide emergency first aid in the event of a
chemical splash. Is there for instance a plentiful supply of running water
near to each dispensing point which could be used to douse a casualty
in an emergency?
Risk
Chemical cross contamination of incompatible substances may result in a
violent reaction.
Precautions
- Always use clean and dry scoops and buckets.
Risk
People may suffer ill health if exposed to airborne chemicals with irritant
or other toxic properties.
Precautions
- Keep containers of chemicals such as ammonia and formaldehyde-based
resins closed.
- Ensure that ventilation in the chemical handling area is adequate to
remove any gases or vapours released.
Risk
Dermatitis may result from prolonged exposure of the skin to chemicals
and water.
Precautions
- Make sure that suitable gloves are worn to prevent skin contact with
chemicals.
- Provide washing facilities of a good standard.
- Provide and encourage the use of a conditioning cream to replace oil
and moisture in the skin after washing.
- Prohibit the use of organic solvent or neat hypochlorite bleach to clean
dye stains from the skin. Sodium hydrosulphite solution or a cleansing
cream that contains sodium hydrosulphite should be used (unless the stains
are from a dye which may regenerate a carcinogen if treated with a reducing
agent). If staining is very stubborn, diluted bleach may be used providing
the skin is then neutralised with sodium hydrosulphite and rinsed thoroughly.
- Inform employees of the characteristic signs of dermatitis. Encourage
them to self-inspect their skin and report any symptoms. Refer any suspected
cases of dermatitis promptly to an occupational health adviser or family
doctor.
Transport by bucket
Risk
Splashes from buckets may result in burns to feet and legs.
Precautions
- Use lidded buckets when carrying hot or corrosive liquids any distance.
- Keep floors in good repair to avoid tripping hazards. Floors of tile
or brick are less prone to chemical corrosion than concrete. Provide spillage
trays at dispensing points.
- Chemical-resistant overalls or a long apron should cover the top of
open-topped workboots to deflect spillages.
Piped delivery systems
Many of the risks mentioned above in connection with dispensing and transport
can be avoided if a piped delivery system is used to convey chemicals directly
from bulk storage to process points. However, such a system presents risks
of its own.
Risk
Pipes and joints may leak.
Precautions
- Use industrial pipework and fittings of suitable material and type for
the substance being conveyed. Do not use push-fit connections or domestic
compression fittings.
- Pipework should be adequately supported. Protect any sections which
may be vulnerable to mechanical damage.
- Use spring-loaded valves which cannot be left open.
Risk
Accidents may occur if mistakes are made during maintenance work upon the
system.
Precautions
- Clearly label or colour mark the pipework according to the chemical
it conveys.
- When breaking into transfer lines and during some other maintenance
work, safety will rely on people following a number of steps in sequence.
These should ensure that the worker is wearing suitable protective equipment
and that the plant being worked upon is effectively drained and isolated.
Where such tasks are routinely undertaken, prepare written procedures
and consider instituting a permit-to-work system.
Addition of 'Hydros' to process vessels
The addition of sodium hydrosulphite, also known as sodium dithionite or
'Hydros' to process vessels continues to give rise to a number of
serious injuries. These have generally arisen when the substance has been
added at too great a rate and has solidified into a plug. The subsequent
reaction is often so violent that it causes the contents to erupt over the
side of the vessel.
Risk
Hydros may react violently upon addition to a vessel
Precautions
- Lay down a safe system of work for the addition of Hydros, particularly
for cleaning dye vessels.
- Do not add Hydros to an item of plant that has previously contained
an oxidising agent such as hydrogen peroxide unless it has been thoroughly
rinsed first.
- Always dispense Hydros into clean, dry containers.
- Ensure adequate ventilation to remove the fumes of sulphur dioxide which
are likely to be evolved upon addition.
- Always ensure Hydros is adequately diluted and that any lumps are broken
up. Consider fixing a mechanical mixer to any vessel which regularly has
Hydros introduced to it.
Other Information Sheets in the Dyeing and Finishing series
No 1 Dyes and chemicals in textile finishing: An introduction
No 3 Dyestuffs: Safe handling in textile finishing
No 4 Hazards from dyes and chemicals in textile finishing: A brief
guide for employees
*No 5 Reactive dyes: Safe handling in textile finishing
*No 6 Dust control in dyestuff handling
* To be published early 1997
Textiles Information Sheets are available from the Textiles, Clothing and
Laundries NIG, HSE, 8 St Paul's St, Leeds LS1 2LE. They are also available
from HSE Books (see Further information for details).
References
- Storage of packaged dangerous substances HS(G)71 HSE Books
1992 ISBN 0 11 885989 7
- The storage of flammable liquids in containers HS(G)51 HSE
Books 1990 ISBN 0 7176 0481 0
- The safe use and handling of flammable liquids HS(G)140 HSE
Books 1996 ISBN 0 7176 0967 7
Further reading
General COSHH ACOP (Control of substances hazardous to health) and
Carcinogens ACOP (Control of carcinogenic substances) and Biological agents
ACOP (Control of biological agents). Control of Substances Hazardous to
Health Regulations 1994. Approved Codes of Practice L5 HSE Books 1995
ISBN 0 7176 0819 0
Personal protective equipment at work. Personal Protective Equipment
at Work Regulations 992. Guidance on Regulations L25 HSE Books 1992
ISBN 0 7176 0415 2
Further information
HSE priced and free publications are available by mail order from HSE Books,
PO Box 1999, Sudbury, Suffolk CO10 6FS Tel: 01787 881165 Fax: 01787 313995.
HSE priced publications are also available from good booksellers.
For other enquiries write
to HSE's Information Centre, Broad Lane, Sheffield S3 7HQ.
This guidance is issued by the Health and Safety Executive.
Following the guidance is not compulsory and you are free to take other
action. But if you do follow the guidance you will normally be doing enough
to comply with the law. Health and Safety inspectors seek to secure compliance
with the law and may refer to this guidance as illustrating good practice.
This publication may be freely reproduced, except for advertising, endorsement
or commercial purposes. The information it contains is current at 6/96.
Please acknowledge the source as HSE.
Printed and published by HSE 6/96 TIS2 C100
Further help:
Further advice can be obtained from HSE offices (see under
Health and Safety Executive in the telephone directory). For
other enquiries
write to HSE's Information Centre, Broad Lane, Sheffield S3
7HQ.
