Carson Ph., Mumford C. Hazardous Chemicals Handbook (Справочник по опасным химическим веществам)

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138 TOXIC CHEMICALS

to health arises due to administration in the course of medical treatment, and substances below

ground in mines, which have their own legislation.)

Substances ‘hazardous to health’ include substances labelled as dangerous (i.e. very toxic,

toxic, harmful, irritant or corrosive) under any other statutory requirements, agricultural pesticides

and other chemicals used on farms, and substances with occupational exposure limits. They

include harmful micro-organisms and substantial quantities of dust. Indeed any material, mixture

or compound used at work, or arising from work activities, which can harm people’s health is

apparently covered.

The regulations set out essential measures that employers (and sometimes employees) have to

take:

• Prohibit use of substances listed in Table 5.20.

• Assess the risk to health arising from work, and what precautions are needed (see Figure 5.3).

Table 5.19 Combination of measures for dust and fume control in the rubber industry

Factory process Health hazard Control measures

Drug room Dust from ‘small drugs’ Substitution

(complex organic compounds) Master batches

Preweighed, sealed bags

Dust-suppressed chemicals

Local exhaust ventilation

Care in handling

Dust from bulk fillers and whitings Local exhaust ventilation

Care in handling

Dust from carbon black Master batches

Local exhaust ventilation

Totally enclosed systems

Not

by ‘careful handling’ alone

Skin contact with process oils Direct metering into mixer

Care in handling and protective clothing.

Compounding Dust Local exhaust ventilation

Master batches

Preweighed, sealed bags

Dust-suppressed chemicals

Care in handling

Fume Local exhaust ventilation

Removal of hot product from workroom –

cool before handling

Skin contact with process oils Direct metering

Care in handling and protective clothing

Moulding Fume Local exhaust ventilation

Removal of hot product from workroom –

cool before handling

Deflection by shields

Calendering and extruding Fume Local exhaust ventilation

Water cooling of extrudate

Dust from release agents Substitution of wet methods

(chalk stearate or talc) Enclosure and local exhaust ventilation

Curing Fume Local exhaust ventilation at autoclave

door and storage racks

Allow autoclave to cool before opening

Spreading Fume Local exhaust ventilation

Care in handling mixes

Table 5.20 Prohibition of certain substances hazardous to health for certain purposes

Substance Purpose for which substance is prohibited

2-Naphthylamine; benzidene; 4-aminodiphenyl; 4-

nitrodiphenyl; their salts and any substance containing any

of those compounds, in a total concentration equal to or

greater than 0.1% by mass

Sand or other substance containing free silica

A substance:

(a) containing compounds of silicon calculated as silica to

the extent of more than 3% by weight of dry material,

other than natural sand, zirconium silicate (zircon), calcined

china clay, calcined aluminous fireclay, sillimanite, calcined

or fused alumina, olivine; or

(b) composed of or containing dust or other matter deposited

from a fettling or blasting process

Carbon disulphide

Oils other than white oil, or of entirely animal or vegetable

origin or entirely of mixed animal and vegetable origin

Ground or powdered flint or quartz other than natural sand

Ground or powdered flint or quartz other than:

(a) natural sand; or

(b) ground or powdered flint or quartz which forms part of a

slop or paste

Dust or powder of a refractory material containing not less

than 80% of silica other than natural sand

White phosphorus

Hydrogen cyanide

Benzene and any substance containing benzene in a

concentration equal to or greater than 0.1% by mass other

than:

(a) motor fuels covered by specific EEC

(b) waste Directives

Manufacture and use for all purposes including any

manufacturing process in which the substance is formed

Use as an abrasive for blasting articles in any blasting apparatus

Use as a parting material in connection with the making of

metal castings

Use in cold-cure process of vulcanizing in the proofing of

cloth with rubber

Use in oiling the spindles of self-acting mules

Use in relation to the manufacture or decoration of pottery

for the following purposes:

(a) the placing of ware for the biscuit fire;

(b) the polishing of ware;

or other articles used for supporting ware during firing;

and

(d) as dusting or supporting powder in potters’ shops

Use in relation to the manufacture or decoration of pottery

for any purpose except:

(a) use in a separate room or building for (i) the manufacture

of powdered flint or quartz or (ii) the making of frits or

glazes or the making of colours or coloured slips for the

decoration of pottery;

(b) use for the incorporation of the substance into the body

of ware in an enclosure in which no person is employed

and which is constructed and ventilated to prevent the

escape of dust

Use for sprinkling the moulds of silica bricks, namely bricks

or other articles composed of refractory material and containing

not less than 80% of silica

Use in the manufacture of matches

Use in fumigation except when:

(a) released from an inert material in which hydrogen cyanide

is absorbed;

(b) generated from a gassing powder; or

applicators other than for fumigation in the open air to

control or kill mammal pests

Uses for all purposes except:

(a) use in industrial processes; and

(b) for the purposes of research and development or for the

purpose of analysis

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140 TOXIC CHEMICALS

• Introduce appropriate measures to prevent or control the risk.

• Ensure that control measures are used and that equipment is properly maintained and procedures

observed.

• Where necessary, monitor the exposure of the workers and carry out an appropriate form of

surveillance of their health.

• Inform, instruct and train employees about the risks and the precautions to be taken.

Assessment

The HSE provide elegant guidance and checklists for conducting and recording risk assessments

in COSHH Essentials (see Bibliography). This is supplemented by guidance sheets on ventilation,

engineering controls and containment for a variety of unit operations including charging reactors;

dipping; filling/emptying sacks/kegs/drums; mixing; sieving; weighing.

The basic steps in any assessment include a review of:

1 What substances are present? In what form?

(a) Substances brought into the workplace.

(b) Substances given off during any process or work activity.

Substances ‘hazardous to health’ can be identified by:

• for brought-in substances, checking safety information on labels and that legally obtainable

from the suppliers, e.g. on their Material Safety Data sheet: making sure it is the most up-to-

date version;

• use of existing knowledge, e.g. past experience, knowledge of the process, understanding of

relevant current best industrial practice, information on related industrial health problems;

• seeking advice from a trade association, others in a similar business, consultants;

• checking whether a substance is mentioned in any COSHH Regulations or Schedules, or listed

in Guidance Note EH 40;

• examination of published trade data, HSE guidance information, literature or documentation;

• checking Part 1 of the approved supply list under the Chemicals (Hazard Information and

Packaging for Supply) Regulations 1994. (Anything listed as very toxic, toxic, corrosive,

harmful or irritant is covered by COSHH.)

Table 5.20 Cont’d

Substance Purpose for which substance is prohibited

The following substances:

chloroform, carbon tetrachloride; 1,1,2-trichloroethane,

1,1,2,2-tetratchloroethane; 1,1,1,2-tetrachloroethane;

pentachloroethane, vinylidene chloride; 1,1,1-trichloroethane

and any substance containing one or more of those substances

in a concentration equal to or greater than 0.1% by mass,

other than:

(a) medical products;

(b) cosmetic products

Supply for use at work in diffusive applications such as in

surface cleaning and the cleaning of fabrics except for the

purposes of research and development or for the purpose of

analysis

Project details/work procedure

Identify substances hazardous to health, quantities, grouping,

mixtures

Establish how they could enter the body and potential effects

Consider

• Who is exposed (remember general public, other groups of

employees, contractors etc.)?

• Under what circumstances (include breakages and spills,

emissions to atmosphere)?

• How much they would be exposed to and for how long?

Prevention of exposure – is it possible?

• Elimination •Enclosure of equipment/apparatus

• Substitution •Ventilation

• Change the process •Exclusion of people from work area

If prevention is not possible, consider control measures, e.g.

•Engineering controls

•Safe systems of work

•Personal hygiene needs

If PPE

or RPE

necessary, information on types required

Emergency procedures following spillage, including first aid

Routine exposure monitoring requirements

Health surveillance requirements

Personnel training needs

Storage arrangements for raw materials, disposal

arrangements for products

Any further action needed to comply with the regulations

Review date for assessment

Keep test records

Keep RPE test

records

Keep records

2 What is the health hazard?

• if breathed in, on contact with the skin or eyes, or if ingested?

• quantity of material used, i.e. small (grams or millilitres), medium (kilograms or litres), or

large (tonnes or cubic metres)?

• how dusty or volatile is the substance?

Figure 5.3

COSHH assessment procedure

PPE = Personal Protective Equipment

RPE = Respiratory Protective Equipment

CONTROL OF SUBSTANCES HAZARDOUS TO HEALTH 141

142 TOXIC CHEMICALS

3 Where and how are the substances actually used or handled?

• Where and in what circumstances are the substances handled, used, generated, released, disposed

of etc.?

• What happens to them in use (e.g. does their form change – such as from bulk solid to dust by

machining)?

• Identify storage and use areas.

• Identify modes of transport.

4 What harmful substances are given off etc.?

5 Who could be affected, to what extent and for how long?

Identify both employees and non-employees – including cleaners, security staff, employees,

contractors, members of the public who could be affected.

6 Under what circumstances?

• Is some of the substance likely to be breathed in?

• Is it likely to be swallowed following contamination of fingers, clothing etc.?

• Is it likely to cause skin contamination or be absorbed through the skin? (NB some materials

have a definite Sk notation in EH 40.)

• Is it reasonably foreseeable that an accidental leakage, spill or discharge could occur (e.g.

following an operating error or breakdown of equipment or failure of a control measure)?

Consider:

• How are people normally involved with the substance?

• How might they be involved (e.g. through misuse, spillage)?

7 How likely is it that exposure will happen?

Check control measures currently in use.

• Check on their effectiveness and whether they are conscientiously/continuously applied.

8 What precautions need to be taken to comply with the rest of the COSHH Regulations?

Having regard to

• who could be exposed,

• under what circumstances,

• the level and possible length of time,

• how likely exposure is,

• the environmental hazards,

together with knowledge about the hazards of the substance (i.e. its potential to cause harm),

conclusions are reached about personal exposure.

The employer’s duty is to ensure that the exposure of employees to a hazardous substance is

prevented or, if this is not reasonably practicable, adequately controlled. Duties under the Regulations

extend with certain exceptions to other persons, whether at work or not, who may be affected by

the employers work.

Control

Prevention of exposure should be given priority, e.g. by:

• changing the process or method of work to eliminate the operation resulting in the exposure;

• process modification to avoid production of a hazardous product, by-product or waste product;

• substitution of a hazardous substance by a new, or different form of the same, substance which

presents less risk to health.

If for a carcinogen prevention of exposure is not reasonably practicable by using an alternative

substance or process there is a requirement to apply all the measures listed in Table 5.21. If these

measures do not provide adequate control then suitable personal protective equipment as will

adequately control exposure must be provided.

Table 5.21 Measures for the control of exposure to carcinogens

• Total enclosure of the process and handling systems unless not reasonably practicable.

• Use of plant, processes and systems of work which minimize the generation of, or suppress and contain, spills, leaks, dust,

fumes and vapours.

• Limitation of quantities in the workplace.

• Keeping the number of persons who might be exposed to a minimum.

• Prohibition of eating, drinking and smoking in areas that may be contaminated.

• Provision of hygiene measures including adequate washing facilities and regular cleaning of walls and surfaces.

• Designation of those areas and installations which may be contaminated and the use of suitable and sufficient warning

signs.

• Safe storage, handling and disposal, and use of closed and clearly labelled containers.

For hazardous substances not classified as carcinogens, where protection of exposure is not

reasonably practicable, adequate control should be achieved by measures other than personal

protection, so far as is reasonably practicable. This is subject to the degree of exposure, circumstances

of use of the substance, informed knowledge about the hazards and current technical developments.

Any combination of the measures listed in Table 5.22 are applicable.

Table 5.22 Measures for the control of exposure to hazardous substances not classified as carcinogens

• Totally enclosed process and handling systems.

• Plant or processes or systems of work which minimize generation of, or suppress or contain, the hazardous dust, fume,

biological agent etc. and limit the area of contamination in the event of spills and leaks.

• Partial enclosure with local exhaust ventilation.

• Local extract ventilation.

• Sufficient general ventilation.

• Reduction of number of employees exposed.

• Exclusion of non-essential access.

• Reduction in the period of exposure for employees.

• Regular cleaning of contamination from, or disinfection of, walls, surfaces etc.

• Provision of means for safe storage and disposal.

• Prohibition of eating, drinking, smoking, application of cosmetics etc. in contaminated areas.

• Provision of adequate facilities for washing, changing and storage of clothing, with arrangements for laundering contaminated

clothing.

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144 TOXIC CHEMICALS

Again when the measures in Table 5.22 do not prevent, or provide adequate control of exposure

there is a requirement to provide suitable personal protective equipment to accomplish it. This

includes respiratory protection, protective clothing generally, footwear and eye protection which,

in the UK, complies with the Personal Protective Equipment Regulations 1992. All routes of

exposure, e.g. inhalation, ingestion, absorption through the skin or contact with the skin, must be

considered.

Control measures in existing work situations should be reviewed, extended or replaced as

necessary to achieve and sustain adequate control.

If leaks, spills or uncontrolled releases of a hazardous substance could occur, means are

required for limiting the extent of health risks and for regaining adequate control as soon as

possible. Where appropriate means should include:

• establish emergency procedures;

• safe disposal of the substance;

• sufficient suitable personal protective equipment to enable the source of the release to be safely

identified and repairs to be made;

• exclusion of all persons not concerned with the emergency action from the area of contamination;

• in the case of carcinogens, ensuring that employees and other persons who may be affected by

an escape into the workplace are kept informed of the failure forthwith.

Exposure limits

Exposures require control such that nearly all people would not suffer any adverse health effects

even if exposed to a specific substance (or mixture of substances) day after day. For certain

substances there are set occupational exposure limits: refer to page 78.

As noted earlier, routes other than inhalation must also be considered. Thus exposure to a

substance which can be hazardous upon ingestion, absorption through the skin or mucous membranes,

or contact with skin or mucous membranes needs control to a standard such that nearly all

the population could be exposed repeatedly without any adverse health effect. (Note that this

will not necessarily protect those who are atopic or with a relevant pre-existing condition, e.g.

dermatitis.)

Maintenance, examination and testing of control measures

An employer has specific obligations to ensure all control measures are kept in an efficient state,

efficient working order and good repair. Engineering controls should be examined and tested at

suitable intervals, e.g. local exhaust ventilation equipment must be tested at least once every

fourteen months, and more often for processes specified in Table 5.23, and a record kept. Respirators

and breathing apparatus must also be examined frequently and the checks recorded.

Monitoring

The exposure of workers should be monitored in certain cases, e.g.

• substances or processes listed in Table 5.24;

• where it is not certain that particular control measures are working properly;

• where it is not possible to be sure that exposure limits are not being exceeded;

• where there could be serious risks to health if control measures were to fail or deteriorate.

Table 5.24 Specific substances and processes for which monitoring is required (Schedule 5, Reg. 10(2))

Substance or process Minimum frequency

Vinyl chloride monomer Continuous or in accordance with a procedure approved

by the Health and Safety Executive

Spray liberated from vessels at which an Every 14 days while the process is being carried on

electrolytic chromium process is carried

on, except trivalent chromium

A record should be kept of any monitoring for at least 5 years, unless it is representative of

personal exposure of identifiable employees when records must be retained for at least 40 years.

Personal/workplace air monitoring

Sampling strategies may include measurement of the hazardous substance:

• in the breathing zone of a worker (personal dosimetry); and/or

• in the workplace air (see Chapter 10).

Biological monitoring

For a few substances exposure may be assessed using biological monitoring (see page 114).

Depending upon the substance the sampling strategy varies from post shift, random, or pre-shift

the day after exposure.

Health surveillance

If a known adverse health effect can reasonably be anticipated under the circumstances of work

– and could readily be observed – some form of health surveillance is appropriate. This may

involve a doctor or trained nurse. It may include the checking of employees’ skin for dermatitis

or asking questions relevant to any asthmatic condition where work is with recognized causative

agents (e.g. epoxy resin curing agents).

In the UK health surveillance is a statutory requirement for the agents, operations and processes

Table 5.23 Frequency of thorough examination and test of local exhaust ventilation plant used in certain processes

(Schedule 4, Reg. 9(2)(a))

Process Minimum frequency

Blasting in, or incidental to cleaning of metal castings, 1 month

in connection with their manufacture

Processes, other than wet processes, in which metal 6 months

articles (other than gold, platinum or iridium) are ground,

abraded or polished using mechanical power, in any room

for more than 12 hours per week

Processes giving off dust or fume in which non-ferrous 6 months

metal castings are produced

Jute cloth manufacture 1 month

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146 TOXIC CHEMICALS

Table 5.25 UK health surveillance requirements

Medical surveillance is required unless exposure is insignificant (Schedule 6 to COSHH Reg. 11(2)a and 5)

Substance Process

Vinyl chloride monomer (VCM) In manufacture, production, reclamation, storage, discharge,

transport, use or polymerization

Nitro or amino derivatives of phenol and of benzene In the manufacture of nitro or amino derivatives of

or its homologues phenol and of benzene or its homologues and the

making of explosives with the use of any of these

substances

Potassium or sodium chromate or dichromate In manufacture

Orthotolidine and its salts In manufacture, formation or use of these substances

Dianisidine and its salts

Dichlorobenzidine and its salts

Auramine In manufacture

Magenta

Carbon disulphide Processes in which these substances are used, or given

Disulphur dichloride off as vapour, in the manufacture of indiarubber or

Benzene, including benzol of articles or goods made wholly or partially of

Carbon tetrachloride indiarubber

Trichloroethylene

Pitch In manufacture of blocks of fuel consisting of coal, coal

dust, coke or slurry with pitch as a binding substance

Health surveillance is appropriate unless exposure is insignificant (Control of Carcinogenic Substances ACOP,

15–18)

Selected relevant legislation

Asbestos Control of Asbestos at Work Regulations 1987 and

subsequent amendments

Compressed air (other than diving operations) Work in Compressed Air Special Regulations 1958

Diving operations Diving Operations at Work Regulations 1981 and

subsequent amendments

Flint, quartz, transfers, colours, Approved Code of Practice. Control of substances

frits, glazes, dusts hazardous to health in the production of pottery.

Control of substances hazardous to health regulations.

Ionizing radiations Ionizing Radiations Regulations 1999

Lead Control of lead at Work Regulations 1998

Pesticides MAFF/HSC Code of Practice for the safe use of

pesticides on farms and holdings.

Approved Code of Practice. Safe use of pesticides for

non-agricultural purposes. Control of substances

hazardous to health regulations.

summarized in Table 5.25. Advice on health surveillance is also given for the agents listed in

Table 5.26.

Health records must be kept of the health surveillance carried out for at least 40 years after the

last entry. Appropriate action should be taken based upon the results, i.e. it should be established

how and when workers should be referred for further examination and how the results will be

used to improve the management of health risks.

Information supply

There is requirement to train and inform employees of:

• the risks arising from their work

• the precautions to be taken

• the results of any monitoring carried out

• the collective (anonymous) results of any health surveillance carried out.

Specific precautions

Ways in which these principles are applied in practice are illustrated in the following section

using common potentially hazardous operations or substances:

• Everyday operations such as painting and welding.

• Toxic dusts such as asbestos and catalysts.

• Hyperpoisons such as cyanides.

• Insecticides.

• Primary irritants and corrosives.

• Common gases such as oxides of carbon and nitrogen, hydrogen sulphide, and inert gases.

• Liquids which pose a health hazard due to volatilization, e.g. mercury and degreasing with

chlorinated solvent, i.e. dry cleaning with perchloroethylene or metal cleaning with

trichloroethylene.

• Liquids posing problems because of the presence of impurities, e.g. mineral oils.

• Use of a strong disinfectant/biocide, i.e. glutaraldehyde.

• Machining operations on metals involving cooling by fluids.

• Application of synthetic resins, e.g. epoxy resins.

• Gases present in buildings, e.g. offices.

Table 5.26 Agents for which health surveillance is advised

Agent UK HSE Guidance Note

Agents liable to cause skin disease EH 26

Antimony EH 19

Arsenic EH 8

Beryllium EH 13

Cotton dust MS 9

Agents causing genetic modification ACGM/HSE Note 4

Isocyanates

EH 16

MS 8

Mineral wool EH 46

Platinum MS 22

Talc dust EH 32

Biological monitoring

Cadmium EH 1

Mercury

EH 17

MS 12

Trichloroethylene EH 5

Biological effect monitoring

Organophosphorus pesticides MS 17

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SPECIFIC PRECAUTIONS 147