Safety Archives - Page 5 of 6 - Outsource Safety Ltd

CDM Regulations 2015; Principal Designers Training Awareness Day

The Construction (Design and Management) Regulations are still raising a huge amount of questions, especially amongst those with new safety duties – designers / architects / structural engineers. We would strongly encourage you to take the time to get some solid guidance which comes (in part) right from the HSE themselves through our Principal Designers Training Day.

We’ve run several of these events and they are always sold out so please book your place soon.

https://www.eventbrite.co.uk/e/designers-awareness-day-plymouth-tickets-25669464058

CDM Regulations 2015; Principal Designers Training Awareness Day

Designer Awareness Day CDM 2015:

– prevention through design
– risk appreciation
– supporting small contractors

The South West Working Well Together (WWT) group and the Health and Safety Executive are inviting you to a Designer Awareness Day.

This is a seminar which will include presentations by the Health and Safety Executive and other experienced Construction industry safety Professionals.

WWT is a construction industry led partnership aiming to improve the standards of health and safety. The goal is to achieve a meaningful and sustained reduction in injury and ill-health in the construction industry.

Many people with design responsibilities are not clear how to address, mitigate or eliminate risk at the design stage and are therefore unable to meet the standards expected of them. Designers have a crucial role in improving the performance of the industry.

This event is supported by the professional institutions and HSE. You will gain valuable information about the Construction (Design and Management) Regulations (CDM 2015) which spells out your duty of care – certificates will be provided.

I look forward to meeting you at this seminar.

Pete Creese, Chair Working Well Together South West

Event Programme:

09:00- 09:15 REGISTRATION TEA/COFFEE AND BREAKFAST ROLL

09:15 – 09:30 Welcome and introduction Pete Creese, Chair WWT South West

09:30 – 12:30

CDM 2015 overview and your role PD
Designing in Fire Safety
Pre-Construction Information
Preparation health and safety File
Red, Amber, Green (RAG) lists and their purpose

During the event industry champions will be on hand to answer questions. Refreshments provided.

PARKING

There is plenty of free parking at Plymouth Training Centre. Please park in the car park provided to the left as you enter for the Training Centre.

Do you have questions about Designers Awareness Day – Plymouth?

Posted by Roger Hart

A Survivors Guide to the Construction Industry; WWT Southwest Event (free)

One of a series of free events which we support with WWT Southwest, this event specifically aims towards the needs of those new to the industry and preventing accidents – ideal for those taking on younger workers and hosting work placements over the summer months

You’re able to book a free place using the link below, read on for more details of what will be covered.

https://www.eventbrite.co.uk/e/a-survivors-guide-to-the-construction-industry-tickets-25668742901

Event Details

FREE Working Well Together Event

A Survivors Guide to the Construction Industry

This is one of a series of free partnership events run by the industry for the industry, as part of the UK-wide Working Well Together (WWT) campaign

The aim of this free Safety and Health Awareness event is to raise awareness of key health and safety issues facing the construction industry today. Also, to give practical advice on how to avoid risks on building sites of all sizes – in particular for Apprentices.

The South West Working Well Together Group is running this event, in conjunction with MGF to get our message to apprentices and trainees in construction alongside their employers.

Health and safety professionals and specialist plant providers will be available throughout the day to answer your questions and you will have the opportunity to see live demonstrations of the latest equipment and techniques.

There is no charge for the event. You will be asked to complete a feedback form in return for a Certificate of Attendance.

Your feedback form will be put into a free prize draw

The prize will be an IPad Mini donated by MGF

Parking is on the campus

Event Programme:

08:30 – 09:00 REGISTRATION TEA/COFFEE AND BREAKFAST ROLL

09:00 – 09:15 Welcome and introduction Pete Creese, Chair WWT South West

09:15 – Finish

The programme will consist of talks and demonstrations on:

Detecting Cables and underground services
Excavation Safety
Silica Dust
Working at Height
Banksman/Signallers/Traffic Management
Behavioural Safety

For further information contact Julia Bone

Tel: 01752 276309

email: julia.bone@hse.gov.uk

Do you have questions about A Survivors Guide to the Construction Industry?

Posted by Roger Hart

Mock trial event, Exeter Guild Hall 29 June 2016, R v Scott Painters Limited

Have you ever wondered what actually goes on behind those locked doors at a trial for health and safety offences?

Now is your chance to see who gets blamed for what and why and how they get sentenced – a real eye opener for all of us and something worth seeing or perhaps encouraging your Managing Director to attend.

This is an event which is run by Working Well Together Southwest, a partnership between the Health and Safety Executive (HSE) and a group of construction and safety professionals, including ourselves.

Even better, our MD, Roger Hart, is the person in the dock! So if you’d like to see him sweating under the glare of the lights and the scrutiny of Pinsent Masons please read more and book your place using the link below.

https://www.eventbrite.co.uk/e/hs-mock-trial-tickets-25168984109

R v Scott Painters Limited

The health and safety team at Pinsent Masons will present a half day mock trial based on a fictional construction based scenario.

This event will follow the legal process of a criminal trial through to the passing of a verdict and will help provide delegates with an idea of what it feels like to “have your day in court”. This is a hugely informative and a must-see event, providing a valuable and sometimes chilling insight into the legal responsibilities of all decision-makers who arrange and carry out construction work, especially Clients and their Contractors.The event is essential viewing for:

Client decision-makers at all levels
Construction Contract managers
Construction Site managers

The charge for the event is
£35 WWT Members
£45 Non WWT Members
BOOK NOW as places are limited.

Event Programme

9.00 – 9.30 Welcome and introduction to the court
9.30 – 12.00 The Trial
12.00 – 12.15 The Verdict
12.15 – 12.30 Discussion on the verdict and questions
12.30 – 13.30 LUNCH

Due to the restricted size of the Guild Hall, places are limited so please book early to avoid disappointment.

Exeter Guild Hall
High Street
EX4 3EB Exeter
United Kingdom

Wednesday, 29 June 2016 from 08:30 to 13:30 (BST)

Posted by Roger Hart

Driving of fork lift trucks (FLTs) on the public highway

This is a question which has been raised by some clients about using fork lift trucks or other materials handling equipment on public roads and highways. Questions have circulated about the need for registration, tax, lights and MOT – read on to find out how you might be affected If you need advice the DVLA can be contacted on 0300 790 6802, please note that we do not provide advice on this issue.

Guidance

Picture of a fork lift truck

Once a vehicle passes onto a public road (or as seen below certain other categories of “road”) further legislation will apply.

The following information has been taken from advice supplied by the Driver and Vehicle Licensing Agency and supporting Guidance V355/1.

The Road Traffic Act 1988 requires that the driver of a motor vehicle when driven on a road must hold the appropriate driving licence, and, if only provisional entitlement is held, to observe the relevant provisional licence conditions.A ‘motor vehicle’ is defined in the 1988 Act as a mechanically propelled vehicle intended or adapted for use on roads. A “road” is defined as any highway, and any other road to which the public has access.

Consequently it would be advisable in our view for an individual to hold the appropriate driving licence entitlement before using any of these vehicles on a “road”.If the fork lift truck is electrically propelled the driver would need a licence covering category L. Alternatively, if the vehicle is exempt from duty, under the Vehicle Excise and Registration Act 1994 because it is used for Agricultural, Horticultural or Forestry purposes (and its road travel does not exceed 1.5km each trip between different areas of land occupied by the same person) a category N licence would suffice. A full category B (motor car) licence gives full cover for both categories L and N.

The Vehicle Excise and Registration Act 1994 provides that any mechanically propelled vehicle used or kept on the public road should be registered, licensed and display registration plates. A fork lift truck can also be licensed within the “works truck” taxation class. The term “Works Truck” means a goods vehicle (that is a vehicle constructed or adapted for use and used for the conveyance of goods or burden of any description) which is designed for use in private premises and used on public roads only;

i) for carrying goods between private premises and a vehicle on a road in the immediate vicinity;

ii) passing between one part and another or to other private premises in the immediate vicinity;

iii) in connection with road works at or in the immediate vicinity of the site of such works.

‘The immediate vicinity’ is a phrase that has been the subject of much debate and ultimately only the courts can decide what is considered to be the ‘immediate vicinity’. We suggest that travelling any distance on a road as qualifying in respect of registration and road tax. To register a fork lift truck you should contact your nearest Vehicle Registration Office. They will also advise you about the taxation position, depending on the form of propulsion and usage that the vehicle in question is put to.

The driver of a fork lift would not be required to hold a driving licence when driving a vehicle on private land/site to which the public has no access, although the insurers of the vehicle may have their own policy on such matters. We would therefore suggest you contact a reputable insurance company to establish whether they would issue insurance cover to a non-licence holder.”

For more information go to www.direct.gov.uk/vehicletax For more information about DVLA’s online services, go to www.direct.gov.uk/onlinemotoringservices

Notes

The “Special Vehicle” tax class encompasses the following vehicles:

Mobile Crane
Mobile Pumps
Digging Machine
Road Roller
Showman’s HGV
Showman’s Haulage Special Trailer

Works Truck – The term “Works Truck” means a goods vehicle (that is a vehicle constructed or adapted for use and used for the conveyance of goods or burden of any description) which is designed for use in private premises and used on public roads only:-i) for carrying goods between private premises and a vehicle on a road in the immediate vicinity; orii) passing between one part and another or to other private premises in the immediate vicinity; oriii) in connection with road works at or in the immediate vicinity of the site of such works.

Vehicles of these descriptions weighing up to 3,500kg pay the PLG rate and tax in the PLG class. Vehicles of these descriptions over 3,500kg pay the basic HGV rate and tax in the Special Vehicles class. If these vehicles are used for purposes outside this concession, the appropriate HGV rate applies.

Exempt Vehicles ‘Limited use’ vehicles, vehicles used by a disabled person, Disabled Passenger Vehicle, Historic vehicles, National Health Service vehicles.

‘Limited Use’ applies to a vehicle used solely in connection with agriculture, horticulture or forestry and its road travel does not exceed 1.5km each trip between different areas of land occupied by the same person.

Posted by Roger Hart

Air sampling for exposure to solvents (toluene, xylene and similar)

If you would like to speak to one of our safety consultants or occupational hygienists about an air sampling survey for wood dusts please contact us on 01453 800100. Outsource Safety specialise in Occupational Health and Hygiene consultancy.

Xylene and toluene sampling methods

An activated charcoal badge type dosimeter was used, attached at the lapel. The badge was left exposed for a recorded period and later washed through with a solvent to extract the analyte which is then passed through a gas chromatography instrument to analyse the concentration of particular substances, in this case xylene and toluene were selected.

Xylene – Background Information

OCCUPATIONAL EXPOSURE STANDARDS

8-HOUR TWA: 100 ppm
15-MINUTE REF. PERIOD: 150 ppm
IDENTITY AND PROPERTIES
CAS No: 1330-20-7
EEC No: 601-022-00-9
Formula: C6H4(CH3)2
Synonyms: xylol, dimethylbenzene
Saturated vapour
concentration: about 8000 ppm at 20oC
Boiling point: 137-144 oC
Conversion factor: 1 ppm = 4.34 mg.m-3 at 25oC

Xylene is an aromatic hydrocarbon with a characteristic odour, perceptible at about 1 ppm. Commercial xylene is a mixture of the three xylene isomers and may contain some ethyl benzene. It is a clear, colourless, mobile, fairly volatile fluid, which is insoluble in water and miscible in other organic solvents. Xylene is classified under the CHIP 2 Regulations (1994) as harmful, to be labelled with risk (R) phrases:

R10: FLAMMABLE
R20/21: HARMFUL BY INHALATION AND IN CONTACT WITH SKIN
R38: IRRITATING TO SKIN

OCCURRENCE AND USE

Xylene is produced mainly from crude oil in the UK, but some also arises from coking processes. It is a component of petrol and hydrocarbon solvent mixtures; and is used in chemical manufacture and as a solvent. Individual isomers are raw materials for making terephthalic acid and phthalic anhydride. It is a carrier solvent for surface coatings (e.g. paints, adhesives, pesticides) supplied for commercial and domestic use.

EXPOSURE

Many thousands of workers may be potentially exposed to xylene, with more than 10 000 user-firms in the UK. Typically, exposures to xylene vapours are controlled to below 50 ppm where xylene is used as a chemical precursor and in the manufacture and use of formulated products. Higher exposures may occur in spray-painting large items, printing, and using xylene-containing products in confined spaces; in these circumstances respiratory protective equipment is worn. Short-term exposures up to 500 ppm have been reported in machine-cleaning operations.

MEASUREMENT

Long-term monitoring is performed by pumped sampling with solvent desorption or by diffusive sampling and thermal desorption {Methods for the determination of hazardous substances MDHS 66 (Rev) MIXED HYDROCARBONS (C5 TO C10) IN AIR – LABORATORY METHOD USING POROUS POLYMER DIFFUSION SAMPLERS, THERMAL DESORPTION AND GAS CHROMATOGRAPHY ISBN 0 7176 0867 0 HSE Books (1995)} and gas chromatographic determination. Measurement of the urinary metabolite methyl hippuric acid is a suitable biological indicator of uptake.

METABOLISM

Xylene vapour is rapidly absorbed through the respiratory tract. It is also absorbed by skin contact, and penetrates many materials used for protective clothing. Over 90% of the absorbed dose is metabolised and excreted in the urine as methyl hippuric acid. A small proportion (5%) is exhaled in the breath.

HEALTH EFFECTS

Animal studies

Exposure to high concentrations of xylene has been shown to cause hearing loss and enlargement of kidneys and liver, due to high metabolic demand. Toxicity to reproduction has been observed, but only at or near levels which are maternally toxic. Xylene gave negative results in carcinogenicity and various mutagenicity tests.

Human data

Minimal eye, nose and throat irritation has been reported at levels down to 100 ppm for 30 minutes, and this can also arise with brief exposures at slightly higher levels. The principal effects known in humans are on the central nervous system. Exposure at 300 ppm affected the sense of balance, caused visual disturbances and slowed reaction-times and some effects were seen at 200 ppm; but exposure to 160 ppm over 4 hours caused no significant adverse health effects. At around 700 ppm for up to 1 hour, headache, dizziness and nausea occur. The isomeric composition of xylene is not considered an important factor in its health effects.

BASIS FOR SETTING THE LIMIT

The critical health effects are irritation and central nervous system effects. The irritant effects reported at 100 ppm appear to be minimal and this was considered to be a no-effect level. In view of these irritancy effects an occupational exposure standard was set at 100 ppm (8-hour TWA). Since irritant effects can arise with even brief exposures at higher levels a short-term OES was set at 150 ppm (15-minute reference period). The limits apply to o-, m- or p- isomers of xylene, or mixtures thereof. A ‘Skin’ notation was considered appropriate to indicate the potential for absorption by this route.

Toluene – Background Information

OCCUPATIONAL EXPOSURE STANDARDS

8-HOUR TWA: 50 ppm
15-MINUTE REF. PERIOD: 150 ppm
NOTATION: SKIN
IDENTITY AND PROPERTIES
CAS No: 108-88-3
EEC No: 601-021-00-3
Formula: C6H5CH3
Synonyms: toluol, methyl benzene
Saturated vapour
concentration: about 30 000 ppm at 25oC
Boiling point: 110.6oC
Conversion factor: 1 ppm = 3.75 mg.m-3 at 25oC

Toluene is an aromatic hydrocarbon with the typical sweet/pungent odour of such substances and an odour threshold around 3 ppm. It is a clear, colourless, mobile, volatile liquid which is insoluble in water and miscible with most organic solvents. Toluene is classified under the CHIP 2 Regulations (1994) as highly flammable and harmful, to be labelled with risk (R) phrases:

R11: HIGHLY FLAMMABLE
R20: HARMFUL BY INHALATION

OCCURRENCE AND USE

Toluene occurs naturally in crude oils and is now produced by catalytic reforming of petroleum feedstocks. About 150 000 tonnes per annum are used in the UK. Toluene has widespread use in the production of a range of industrial chemicals, and as a solvent in adhesives, including rubber solutions, coatings and printing inks. It is a common component of many mixed petroleum hydrocarbon solvents.

EXPOSURE

A large number of workers are potentially exposed to toluene. Processes at which exposure to toluene is well-controlled are in the petrochemical sector; exposures are fairly well controlled in the footwear industry (adhesives), silk-screen printing, chemicals production, paint manufacture and decorating industries. In each case mean exposures are less than 15 ppm with more than 96 % of samples less than 100 ppm. Poorly controlled processes include rubber-coating, machine-cleaning, and general adhesives uses, where mean exposures range from 15 to 89 ppm with only around two thirds of samples less than 100 ppm. High short-term exposures can be experienced at liquid transfer points and during manual cleaning. There is a potential for domestic exposure from paint and adhesives.

MEASUREMENT

Short-term measurement can be performed by colorimetric detector tubes, and continuous monitoring is with meters, but these may not be selective for toluene. Long-term measurement is by pumped sampling onto charcoal with solvent desorption, {Methods for the determination of hazardous substances MDHS 36 (Rev) TOLUENE IN AIR – LABORATORY METHOD USING PUMPED CHARCOAL ADSORPTION TUBES, SOLVENT DESORPTION AND GAS CHROMATOGRAPHY ISBN 0 11 885960 9 HSE Books (1990)} or diffusive sampling with thermal or solvent desorption, {Methods for the determination of hazardous substances MDHS 40 (Rev) TOLUENE IN AIR – LABORATORY METHOD USING PUMPED POROUS POLYMER ADSORBENT TUBES, THERMAL DESORPTION AND GAS CHROMATOGRAPHY ISBN 0 11 885961 7 HSE Books (1990)} and gas chromatographic determination. Biological assessment of toluene exposure is by measuring blood-toluene at the shift-end.

METABOLISM

Toluene is readily absorbed by the respiratory tract, and is also absorbed through the skin. It is rapidly distributed, accumulating to some extent in fat and also the liver, brain and lung. Some toluene is exhaled: otherwise it is metabolised to hippuric acid and o-cresol, which are excreted in urine over an extended period.

HEALTH EFFECTS

Animal studies

Inhalation studies showed narcosis at 10 000 ppm, following central nervous system effects. In repeated studies at high exposures, kidney and liver damage occurred, with no effects at 200 ppm. It is difficult to form firm conclusions on findings that exposure to toluene may cause hearing or eyesight impairment.

IN VIVO and IN VITRO studies show toluene is unlikely to be carcinogenic or mutagenic. Toluene only showed teratogenic effects at high doses.

Human data

The principal effects are on the central nervous system with impaired reaction times and vigilance reported for exposures to 200 or 240 ppm for 3 to 7 hours, and dizziness, headache and fatigue reported following exposure at 50 to 100 ppm for 4 to 8 hours. Although longer term effects on the central nervous system have been claimed, there is no substantive evidence that they occur following repeated exposures between 50 and 200 ppm. Toluene vapour is irritating to the eyes and respiratory tract, with no effects being reported at 80 ppm. The liquid irritates the skin. There are no data on carcinogenic effects in humans.

BASIS FOR SETTING THE LIMIT

The critical health effect is upon the central nervous system. A level could be identified which was unlikely to be injurious to employees, and an occupational exposure standard was set at 50 ppm (8-hour TWA) on this basis. However, this implies a need to introduce improvements in control in some industry sectors. A short-term OES was set at 150 ppm (15-minute reference period) which would minimise short-term effects such as irritation. A ‘Skin’ notation was considered appropriate.

Posted by Roger Hart

The safety of bottled water in cars

This is a question which has been raised by some clients following a spate of emails circulating on the web. Read on to find out the opinion of our experienced safety consultants and if you have questions or need more advice please call our safety consultancy on 01453 800100.

Below is a copy of the email (in italics) which started this urban myth;

Email Subject: Drinking Bottled Water Kept in Car

…a friend whose mother recently got diagnosed with breast cancer. The doctor told her women should not drink bottled water that has been left in a car. The doctor said that the heat and the plastic of the bottle have certain chemicals that can lead to breast cancer. So please be careful and do not drink that water bottle that has been left in a car and pass this on to all the women in your life.

This information is the kind we need to know and be aware and just might save us!!!!

*The heats causes toxins from the plastic to leak into the water and they have found these toxins in breast tissue. Use a stainless steel canteen or a glass bottle when you can*!

The first alarm bell which rings here and announces this email as something which may not be 100% true is the fact that all materials containing food stuffs must pass stringent tests before being put into use.

However, there is as usual an element of truth, bottles can potentially leach endocrine disruptors into the water which they contain, in this case man made chemicals which have the potential to interfere with the production of reproductive hormones in the body – not cause cancer.

Research on this subject is in its early stages and there may not be a link – more research is needed but it is a potential concern. Some chemical leaching does take place but these are at levels which are minuscule and do not pose a threat to health. Tests have shown them to always be within the limits set within the EU and US authorities. You’re greatest risk is from microbial contamination, particular in the case of still mineral waters which will not have undergone special treatment to reduce these levels.

The bottom line is that single use water bottles are known to be safe and multiple use water bottles are also safe to the best of current knowledge. Nothing is without risk but you should not be concerned by leaving water bottles in cars but you might not want to drink the warm water anyway – unless you’re very thirsty!

Notes

Some concerns have also been raised involving reusable water bottles and the leaching of bisphenol A (BPA). You may now see a number of baby bottles boasting to be BPA free. This is potentially a concern but research continues into this to establish the actual level of risk and its true effects on the human body.

Posted by Roger Hart

Choosing a dust mask

We often have questions regarding which mask should be used and so thought a very quick summary here would be useful.

In general, filtering face masks used for dusts and similar can be categorised into three types all with an FFP number.

FFP1 for simple dusts such as nuisance and soft wood dusts
FFP2 for more hazardous dusts such as grinding, powder painting or respirable cystalline silica
FFP3 for hazardous dusts which also involve some vapours and gases which are hazardous to health (a good example here would be welding fumes)

One of the key failing when we review the use of face masks is how people wear them and you should, since November 2002 in fact, be testing the fit of these items to ensure they are effective – this is known as fit testing.

Many people do not fit masks well and do not even press the metal strip fixed around the nose of the mask to get a good seal – if a mask is to protect you this is essential. A second common error is keeping the mask at the point of work uncovered – perhaps on a work bench. This will allow the mask to collect exactly what it should be protecting you from and allow you to inhale it as soon as you use it! Always keep RPE in a sealed container or bag to prevent this type of contamination.

More information is supplied below on the new APF figures. These allow you, once occupational hygienists, such as ourselves, have completed an appropriate air sampling survey, to select an item of RPE which will adequately protect you and your staff from harm (see graphic to the right for more information). The APF is an allowance over which the mask will protect you;

For example; the allowable limit for hard and soft wood dusts is currently 5 mg per cubic metre. In your workplace an occupational hygienist such as one of our safety consultants may measure the dust level at 3 times this amount, 15 mg per m3. In that case you would need to seek an APF (assigned protection factor) of at least 3. This would put you in the typical 4-10 or 4-20 range.

One final point concerns the amount of time which a mask will last before requiring replacement, this can be summarised as follows;

For particulate (dusts) when breathing become more difficult the mask will be partially blocked and should be replaced
For gases and vapours the mask should be replaced when you detect ‘breakthrough’ i.e. when you can detect through smell or taste the item against which you should be protected be that a solvent or other substance.

As a general rule, disposable masks should be disposed of daily and reusable half face respirators should have their filters changed at least monthly.

If you would like to speak to an experienced occupational hygienist about this please contact us on 01453 800100

Posted by Roger Hart

Air sampling for exposure to isocyanate (MDI, TDI and similar isocyanates)

If you would like to speak to one of our safety consultants or occupational hygienists about an air sampling survey for isocyanate exposure please contact us on 01453 800100.

ISOcyanate air sampling method

The methods closely follows the recommendations of HSE MDHS 25/3 and the principle is as follows;

A measured volume of air is drawn through a glass fibre filter impregnated with 1-(2-methoxyphenyl) piperazine mounted in a sampler and attached in the breathing zone of the exposed worker. The Methylene Di-isocyanate (MDI) is held on the filter for subsequent High Pressure Liquid Chromatography (HPLC) analysis using ultraviolet and electrochemical detection. The results of this analysis, coupled with the flow rate and time period, enable the exposure levels to be quoted as milligrams per cubic metre (mg.m-3) for application to the exposure limit published in HSE Document EH40/2001.

ISOCYANATES

all (as -NCO)

MAXIMUM EXPOSURE LIMITS

8-HOUR TWA: 0.02mg.m-3

15-MINUTE REF. PERIOD: 0.07mg.m-3

NOTATION: SENSITISER

IDENTITY AND PROPERTIES

Isocyanate is the functional group (-NCO) which occurs in a number of substances and their reaction mixtures. The saturated vapour concentration at 25oC varies with the substance; refer to manufacturers data sheet.

Conversion factors:

di-isocyanate 1 ppm = 3.44mg.m-3 -NCO at 25oC

isocyanate 1 ppm = 1.72mg.m-3 -NCO at 25oC

Isocyanates react rapidly with all substances having ‘available hydrogen’. This includes alcohols, amines and amide groups in proteins. Isocyanates are soluble in many organic solvents and decompose at varying rates in water. Substances carrying the isocyanate group are not detectable by smell until many times the exposure limit (for example, TDI odour threshold is about 30 times the MEL).

OCCURRENCE AND USE

Organic isocyanates may arise from burning polyurethane. Only MDI is produced in the UK, by reacting methylene dianiline with phosgene in a closed process; other isocyanates are imported. About 60,000 tonnes per annum of isocyanates are used in the UK, of which about half is used for polyurethane foam, and the rest for surface coatings (paints, lacquers, inks, adhesives), foundry core binders and synthetic rubbers.

EXPOSURE

The number of persons who may be occupationally exposed to isocyanate is not known. In general, exposure can be minimised by using isocyanate prepolymers of low volatility. Control measures such as suitable extraction ventilation and use of airline breathing apparatus are needed where isocyanate aerosols or significant vapour concentrations may occur.

Exposures above 0.02 mg.m-3 isocyanate may be experienced in spray-painting large articles, with exposures briefly exceeding 0.06 mg.m-3, Respiratory protective equipment is required for these processes. In most foam plants, exposure is controlled to below 0.01 mg.m-3 isocyanate. Molten MDI can give rise to high exposures if the fume is not extracted.

MEASUREMENT

Methods based on air sampling through bubbler solutions and subsequent instrumental or colorimetric analysis are detailed in MDHS 25.

METABOLISM

The main exposure route is by inhalation of vapour, aerosol mist or dust. Isocyanate reacts rapidly with respiratory tract surfaces; its further metabolic fate is not known.

HEALTH EFFECTS (Human data)

The isocyanate group (-NCO) is the functional group which causes the adverse health effect. Heavy exposure has been associated with bronchitis. There have been numerous reports on asthma due to isocyanates, but the levels which can induce sensitisation are unknown although there are anecdotal reports suggesting that peak exposures may be important. Sensitised individuals may react with severe asthmatic symptoms at very low concentrations of isocyanate, in some cases below 0.02 ppm. The development of sensitisation may occur within months of exposure, or only after years of symptom-free exposure. Sensitisation may result in the development of bronchial hyper-reactivity, and the affected individual responds to non-specific stimuli such as cold air and exercise. In these individuals, recovery may not follow cessation of exposure. Health surveillance is appropriate. {EH 16 ISOCYANATES: TOXIC HAZARDS AND PRECAUTIONS ISBN 0 11 883581 5 HSE Books (1984)}

BASIS FOR SETTING THE LIMIT

The critical health effect of isocyanates is respiratory sensitisation and in the absence of dose-response data a no-adverse-effect level cannot be established. Consequently a maximum exposure limit was considered appropriate. This was set at 0.02 mg.m-3 (8-hour TWA) isocyanate, with a 15-minute reference period MEL set at 0.07 mg.m-3 isocyanate.

Posted by Roger Hart

Understanding noise exposure terms

Noise exposure terminology – Take a look at our explanatory video below and check below that for our glossary:

Exposure action values (EAV): Levels of noise exposure to noise at which certain actions need to be taken. The values are:

Lower exposure action values (LEAV):
daily or weekly exposure of 80 dB:
peak sound pressure of 135 dB;
Upper exposure action values (UEAV):
daily or weekly exposure of 85 dB;
peak sound pressure of 137 dB.

Exposure action values and noise exposure limit values
	Daily or weekly personal average noise exposure	Peak sound level	Actions
Below lower exposure action values	Less than 80 dB (A-weighted)	Less than 135 dB (C-weighted)	Reduce noise levels as far as reasonably practicable.
Lower exposure action values	80 dB (A-weighted) or aboveCannot take the effect of hearing protection into account	135 dB (C-weighted) or aboveCannot take the effect of hearing protection into account	Undertake risk assessment. If any employees are identified as being particularly susceptible to noise, health surveillance should be implemented. Make suitable hearing protection available. Establish a maintenance programme for equipment supplied to reduce noise risk such as noise limiters and hearing protection. Provide training.
Upper exposure action values	85 dB (A-weighted) or aboveCannot take the effect of hearing protection into account	137 dB (C-weighted) or aboveCannot take the effect of hearing protection into account	Implement the actions required by lower exposure action values (above). Establish and implement a programme of control measures. If these measures are not sufficient to reduce exposure below 85 dB then: suitable hearing protection must be worn; and a health surveillance programme implemented.
Exposure limit values	87 dB (A-weighted) Allowed to take hearing protection into account	140 dB (C-weighted) Allowed to take hearing protection into account	Must reduce to below limit values.

L_Aeq: The ‘equivalent’ continuous noise level that would deliver the same noise dose as a varying level over a given period, and is a good way of describing the average level of noise.

L_EP,d: Daily personal noise exposure level. It is averaged over an 8-hour period rather than the actual time in the work environment.

L_EP,w: Weekly personal noise exposure level. It is averaged over a period of 5 days (40 hours) by measuring the noise exposure on each of 7 days, then dividing the result by 5.
Limit values: See ‘Exposure limit values’.

Noise dose: See ‘Noise exposure’.

Noise exposure: ‘The noise dose’, which can be calculated, takes account of the actual volume of sound and how long it continues. Noise exposure is not the same as sound level, which is the level of noise measured at a particular moment.

Noise limiters: Sometimes known as volume regulatory device (VRD), controls noise exposure from amplified music. Modern noise limiters can be fitted with anti-tamper relays connected to external switches to improve system security.

Noise measurements: Decibels (dB) are used for measuring noise. A-weighting is used to approximate to the frequency response of the human ear. C-weighting is used to measure peak, impact or explosive noise.

Occlusion effect: Occurs when an object (like an unvented earplug) completely fills the outer portion of the ear canal. This changes the way sounds are produced in the ear canal, especially noises produced by the body (for example breathing, swallowing and noise travelling through bone and tissue.) The result is these noises appear louder.

Simple listening checks: An easy way of establishing whether there might be a noise problem. Where it is difficult to hold a normal conversation without shouting or where there is live amplified music (as in a pub, club or pop concert) it is probable that the noise is above the lower exposure action value.

Single number rating (SNR) value: Method of indicating the degree of protection offered by a hearing protector.

Sound restoration: Device in earmuffs that reduces ambient noise levels to allow relayed communication or other signals at a reduced level.

Three-decibel rule: The sound intensity doubles with every three dB increase. Thus sounds at 88 dB are actually twice as intense as they are at 85 dB and 115 dB is 1000 times as intense as 85 dB.

Tinnitus: Buzzing, ringing or tone in the ear. Temporary tinnitus is a warning; a sign that ‘you got away with it that time.’

VRD: Volume regulatory device (see noise limiter).

We carry out all noise assessments requirement using our experienced safety consultants. If you have a need for noise assessment please call us on 01453 800100.

Posted by Roger Hart

Fire Safety – Assessing the means of escape

Fire risk assessment – assessing the means of escape

The range of workplaces covered by these regulations is huge and so the following information is intended as a guide to get you started on an assessment. Our advice is to get expert help from one of our experienced safety consultants conducting a fire risk assessment at your premises, please call us on 01453 800100 or contact us for more information on our safety consultancy and fire risk assessment / fire risk audit services.

Please note that in some cases, it may be necessary to provide additional means of escape or to improve the fire protection of existing escape routes. At this point you should consult the fire authority and, where necessary, your local building control officer before carrying out any alterations. The distances given below should ensure that people are able to escape within the appropriate period of time. You can of course use actual calculated escape times but should do so only after consulting a fire safety consultant with appropriate training and expertise in this field.

Fire risk categories for assessing the means of escape

In general, most workplaces can be categorised as high, normal or low risk. Examples of the type of workplace or areas within workplaces likely to fall within these categories are:

High

Where highly flammable or explosive materials are stored or used (other than in small quantities).
Where unsatisfactory structural features are present such as:
lack of fire-resisting separation;
vertical or horizontal openings through which fire, heat and smoke can spread;
long and complex escape routes created by extensive subdivision of large floor areas by partitions, or the distribution of display units in shops or machinery in factories; and
large areas of flammable or smoke-producing surfaces on either walls or ceilings.
Where permanent or temporary work activities are carried out which have the potential for fires to start and spread such as:
workshops in which highly flammable materials are used, e.g. paint spraying;
areas where the processes involve the use of naked flame, or produce excessive heat;
large kitchens in works canteens and restaurants;
refuse and waste disposal areas; and
areas where foamed plastics or upholstered furniture are stored.

or, where there is a significant risk to life in case of fire, such as where:

sleeping accommodation is provided for staff, the public or other visitors in significant numbers;
treatment or care is provided where the occupants have to rely upon the actions of limited numbers of staff for their safe evacuation;
there is a high proportion of elderly or infirm people, or people with temporary or permanent physical or mental disabilities, who need assistance to escape;
groups of people are working in isolated parts of the premises such as basements, roof spaces, cable ducts and service tunnels etc; and
large numbers of people are present relative to the size of the premises (e.g. sales at department stores) or in other circumstances where only a low level of assistance may be available in an emergency (e.g. places of entertainment and sports events).

Normal

Where any outbreak of fire is likely to remain confined or only spread slowly, allowing people to escape to a place of safety.
Where the number of people present is small and the layout of the workplace means they are likely to be able to escape to a place of safety without assistance.
Where the workplace has an effective automatic warning system, or an effective automatic fire-extinguishing, -suppression or -containment system, which may reduce the risk classification from high risk.

Low

Where there is minimal risk to people’s lives and where the risk of fire occurring is low, or the potential for fire, heat and smoke spreading is negligible.
The work you have done on assessing the risks and reducing the risk of fire occurring, together with the knowledge you have gained about the location of people at risk, should generally provide you with the information you need to establish the risk category or categories of your workplace.

General principles for escape routes

Other than in small workplaces, or from some rooms of low or normal fire risk, there should normally be alternative means of escape from all parts of the workplace. Routes which provide means of escape in one direction only (dead-end) should be avoided wherever possible as this could mean that people have to move towards a fire in order to make their escape. Escape routes should be independent of one another and arranged so that people can move away from a fire in order to make their escape and should always lead to a place of safety. Remember that they should also be wide enough for the number of occupants and should not normally reduce in width and be kept clear of obstruction at all times.

Evacuation times and length of escape routes

The aim is, from the time the fire alarm is raised, for everyone to be able to reach a place of relative safety, i.e. a storey exit (see ‘Technical terms relating to means of escape’), within the time available for escape.The time for people to reach a place of relative safety should include the time it takes them to react to a fire warning.

This will depend on a number of factors including:

what they are likely to be doing when the alarm is raised, e.g. sleeping, having a meal etc;
what they may have had to do before starting to escape, e.g. turn off machinery, help other people etc; and
their knowledge of the building and the training they have received about the routine to be followed in the event of fire.
Where necessary, you can check these by carrying out a practice drill.

To ensure that the time available for escape is reasonable, the length of the escape route from any occupied part of the workplace to the storey exit should not exceed:

Where more than one route is provided

25 metres – high-fire-risk area;
45 metres – normal-fire-risk area;
60 metres – low-fire-risk area.

Where only a single escape route is provided

12 metres – high-fire-risk area;
18 metres – normal-fire-risk area (except production areas in factories);
25 metres -low-fire-risk area.

Where the route leading to a storey exit starts in a corridor with a dead-end, then continues via a route which has an alternative, the total distance should not exceed that given above for ‘Where more than one route is provided’. However, the distances within the ‘dead-end portion’ should not exceed those given for ‘Where only a single escape route is provided’.

People with disabilities

You may need to make special arrangements for staff with disabilities, which should be developed in consultation with the staff themselves. British Standard 5588: Part 8 gives guidance and provides full information.

Premises providing residential care and/or treatment

The distances shown in the paragraphs above may not be suitable for workplaces providing residential care – you should seek specialist advice from your fire safety consultant in this situation.

Number and width of exits

There should be enough available exits, of adequate width, from every room, storey or building. The adequacy of the escape routes and doors can be assessed on the basis that:

a doorway of no less than 750 millimetres in width is suitable for up to 40 people per minute (where doors are likely to be used by wheelchair users the doorway should be at least 800 millimetres wide); and
a doorway of no less than 1 metre in width is suitable for up to 80 people per minute.
Where more than 80 people per minute are expected to use a door, the minimum doorway width should be increased by 75 millimetres for each additional group of 15 people.

For the purposes of calculating whether the existing exit doorways are suitable for the numbers using them, you should assume that the largest exit door from any part of the workplace may be unavailable for use. This means that the remaining doorways should be capable of providing a satisfactory means of escape for everyone present.

Inner rooms

You should avoid situations where the only escape route for people in an inner room is through one other room (the access room). The exception to this is where the people in the inner room can be quickly made aware of a fire in the outer one and this is not an area of high fire risk. Where there is no automatic fire detection system, it may be reasonable to provide a self-contained smoke alarm which is solely within the access room, as long as it is clearly audible within the inner room.

Corridors

Corridors should generally be a minimum of 1 metre wide (although wheelchair users will need a width of 1.2 metres and a width of 1.5 metres is preferable). The doors should be aligned with the walls of the rooms so that the floor area is effectively divided into two or more parts. To avoid having to travel long distances in corridors affected by smoke, those corridors which are more than 30 metres long (45 metres in offices and factories) should be subdivided into approximately equal parts by providing, close-fitting, self-closing fire doors.

Where a corridor only leads in one direction, or serves sleeping accommodation, it should be constructed of fire-resisting partitions and self-closing fire doors (this does not apply to toilets).

If you would like assistance with any aspect of fire risk assessment please call one of our expert fire safety consultants on 01453 800100. We can complete a comprehensive fire risk assessment / fire risk audit for your workplace, just contact us to find out more.

Posted by Roger Hart

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