Unions are calling for better toilet facilities for workers after research suggested some are using bags, bottles and buckets to relieve themselves because of a lack of loos.

A survey of 4,000 workers by the TUC found that almost three in five said they do not always have the opportunity to use a toilet when they need to, with many citing a lack of breaks or access during shifts.

These included train, bus and delivery drivers, teachers who cannot leave children unattended and warehouse workers the union organisation said were punished for taking time out to use the toilet.

Almost half of other workers such as postal staff, firefighters and builders said they do not always have access to a toilet.

One in four of those who do have access to toilets reported that they are either unclean, poorly functioning, or not fit for use.

A postal worker surveyed said: “I have to keep a bottle, funnel, wipes and hand sanitiser in the back of the van in case my bladder can’t hang on until the next available pub or public toilet.”

A female firefighter said: “During a night shift I don’t drink as I should as there’s a great lack of facilities at an incident. This goes against hydration policy, but I don’t want to wet myself in front of a male-oriented workforce.”

The TUC is calling on employers to improve workers’ access to toilets by allowing longer breaks and partnering with local authorities and businesses to improve facilities for mobile workers.

TUC assistant general secretary Kate Bell said: “We all deserve dignity at work but carrying a bucket or a bottle around as your toilet is not dignified for anyone and holding out when you need to go can lead to health problems.

“Toilet access can be especially important for some, including pregnant workers or those with health conditions that may require frequent or fast access to a toilet.

“It might not be something a person likes to talk about, so employers should consider how staff with specific toilet needs can have them met with dignity and confidentiality.

“The decline in public toilets has made life especially hard for people like delivery workers or tradespeople who are out and about all day.”

Mick Whelan, general secretary of the train drivers union Aslef added: “It cannot be right that train drivers are often left with no dignified or hygienic options for carrying out basic bodily functions.

“This problem only serves to undermine efforts by stakeholders in the rail industry to recruit a more representative number of women to the driver’s seat.

“Some train drivers choose not to drink tea or coffee or water – ‘deliberate dehydration’ – to avoid having to go to the toilet. Not maintaining good fluid levels has an effect on concentration, and harmful long-term effects on health, too. Drivers’ cabs can reach temperatures of 30°C in the summer heat.

“Some drivers are having to change sanitary towels in bushes by the side of the track – that’s outrageous in a first world country in the 21st century.”

Unite general secretary Sharon Graham said: “The right to decent toilets while at work should be a given. It defies belief that in the 21st century, workers are still being denied access to decent toilets.

“Employers should be in no shadow of doubt. Not giving workers proper access to toilets is totally unacceptable. Unite is ready to take on any employer that won’t meet this basic requirement with the whole force of the union.”

Richard Hines, Office of Rail and Road’s HM Chief Inspector of Railways, said: “The welfare of the people who work on our railways is vitally important.

“Whilst the industry has invested and made tangible improvements over time in welfare provision across the network, it is clear from our interventions that further work is required.

“I am therefore convening a rail industry round-table which will focus on securing further improvements to appropriate welfare facilities for workers, recognising that this is a complex issue with no simple solutions.

“By working collaboratively, we can build on the progress that has already been made and establish a clear, industry-led strategy for improvement.

“This will also help us to build a more diverse and inclusive railway workforce that is representative of the people we serve now, and in the future.”